Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/12—Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
  • A61B17/12022—Occluding by internal devices, e.g. balloons or releasable wires
  • A61B17/12099—Occluding by internal devices, e.g. balloons or releasable wires characterised by the location of the occluder
  • A61B17/12109—Occluding by internal devices, e.g. balloons or releasable wires characterised by the location of the occluder in a blood vessel
  • A61B17/12113—Occluding by internal devices, e.g. balloons or releasable wires characterised by the location of the occluder in a blood vessel within an aneurysm
  • A61B17/12118—Occluding by internal devices, e.g. balloons or releasable wires characterised by the location of the occluder in a blood vessel within an aneurysm for positioning in conjunction with a stent
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/12—Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
  • A61B17/12022—Occluding by internal devices, e.g. balloons or releasable wires
  • A61B17/12131—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
  • A61B17/1214—Coils or wires
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/12—Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
  • A61B17/12022—Occluding by internal devices, e.g. balloons or releasable wires
  • A61B17/12131—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
  • A61B17/1214—Coils or wires
  • A61B17/1215—Coils or wires comprising additional materials, e.g. thrombogenic, having filaments, having fibers, being coated
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/12—Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
  • A61B17/12022—Occluding by internal devices, e.g. balloons or releasable wires
  • A61B17/12131—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
  • A61B17/1214—Coils or wires
  • A61B17/12154—Coils or wires having stretch limiting means
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/12—Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
  • A61B17/12022—Occluding by internal devices, e.g. balloons or releasable wires
  • A61B17/12131—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
  • A61B17/12168—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a mesh structure
  • A61B17/12172—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a mesh structure having a pre-set deployed three-dimensional shape
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/12—Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
  • A61B17/12022—Occluding by internal devices, e.g. balloons or releasable wires
  • A61B17/12131—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device
  • A61B17/12168—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a mesh structure
  • A61B17/12177—Occluding by internal devices, e.g. balloons or releasable wires characterised by the type of occluding device having a mesh structure comprising additional materials, e.g. thrombogenic, having filaments, having fibers or being coated
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D23/00—Producing tubular articles
  • B29D23/18—Pleated or corrugated hoses
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00526—Methods of manufacturing
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00526—Methods of manufacturing
  • A61B2017/0053—Loading magazines or sutures into applying tools
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00831—Material properties
  • A61B2017/00893—Material properties pharmaceutically effective
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00831—Material properties
  • A61B2017/00898—Material properties expandable upon contact with fluid
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00831—Material properties
  • A61B2017/00942—Material properties hydrophilic
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/12—Surgical instruments, devices or methods, e.g. tourniquets for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord
  • A61B17/12022—Occluding by internal devices, e.g. balloons or releasable wires
  • A61B2017/1205—Introduction devices
  • A61B2017/12054—Details concerning the detachment of the occluding device from the introduction device
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/08—Accessories or related features not otherwise provided for
  • A61B2090/0807—Indication means
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/39—Markers, e.g. radio-opaque or breast lesions markers
  • A61B2090/3966—Radiopaque markers visible in an X-ray image
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2002/823—Stents, different from stent-grafts, adapted to cover an aneurysm

Definitions

• This application relates to medical devices, and more particularly, to vascular implants for occluding vasculature and methods of manufacturing the vascular implants.
• An aneurysm is a localized, blood filled balloon-like bulge that can occur in the wall of any blood vessel, as well as within the heart.
• One endovascular treatment option for aneurysms is complete reconstruction of the damaged vessel using a vascular prosthesis or stent-graft.
• a stent-graft is an implantable tubular structure composed of two parts, a stent and a graft.
• the stent is a mesh-like structure made of metal or alloy which functions as a scaffold to support the graft.
• the graft is typically a synthetic fabric that is impervious to blood flow and lines the stent.
• Stent-grafts are not a treatment option for intracranial aneurysms due to the risk of cutting off blood flow to feeder vessels that may be vital for brain function.
• Stent- grafts can also be stiff, hard to deliver/retract, and can be highly thrombogenic within the parent vessel, all of which are undesirable features for intracranial aneurysm treatment.
• endovascular treatment of intracranial aneurysms has centered on packing or filling an aneurysm with material or devices in order to achieve a high packing density to eliminate circulation of blood, which leads to thrombus formation and aneurysm closure over time.
• Mechanical vaso-occlusive devices are another option for filling an aneurysm.
• One type of mechanical vaso-occlusive device for the placement in the sac of the aneurysm is a balloon.
• Balloons are carried to the vessel site at the end of a catheter and inflated with a suitable fluid, such as a polymerizable resin, and released from the catheter.
• a suitable fluid such as a polymerizable resin
• Other types of mechanical vaso-occlusive devices are composed of metals or alloys, and biocompatible fibers, for example.
• the materials are formed into tubular structures such as helical coils.
• One of the earliest fibered coils was the Gianturco coil (Cook Medical). This coil was formed from a 5 cm length of 0.036” guidewire (inner core removed) and featured four 2 inch strands of wool attached to one tip of the coil to promote thrombosis. This device was difficult to introduce into tortuous vessel sites less than 3 mm in diameter. This is generally because the coil was stiff or bulky and had a high coefficient of friction.
• Chee et al. (U.S. Pat. No. 5,226,911) introduced a more deliverable fibered coil with fibers that were directly attached to the length of the coil body. This coil was designed for more tortuous anatomy by decreasing the amount of thrombogenic material being delivered with the coil.
• Other examples of coils are U.S. Pat. No. 4,994,069 to Ritchart et al.; U.S Pat. No. 5,354,295 and its parent, U.S. Pat. No. 5,122,136, both to Guglielmi et al.
• Materials can also be formed into tubes/strings/braided sutures (see, e.g., U.S. Pat. No. 6,312,421 to Boock; U.S. patent application Ser. No. 11/229,044 to Sepetka et al.; U.S. patent application Ser. No 13/887,777 to Rees; U.S. patent application Ser. Nos. 13/552,616 and 10/593,023 both to Wu et al.), cables (see, e.g., U.S. Pat. No. 6,306,153 to Kurz et al.), or braids. Metal coils can also be covered by winding on thrombogenic fiber as described in U.S. patent application Ser. No 12/673,770 to Freudenthal and U.S. Pat. No. 6,280,457 to Wallace et al.
• braided or polymer coils can be further divided into non-expandable and self-expandable devices.
• These devices can be made from materials such as textiles, polymers, metal or composites using known weaving, knitting, and braiding techniques and equipment. Included in the weave or the finished braid can be optional mono or multifilament fiber manufactured to impart additional features or effects (e.g., radiopacity and thrombogenicity).
• Non-expandable braids can act as the implant and be mainly metallic, polymer, or a combination of metal and polymer.
• braids have some minimal space between the filaments (braid strands) resulting in open cell designs.
• tight, mostly metal braids employing such designs result in stiff structures which are difficult to track via catheter or risk injury to the vasculature.
• metal braided structures may be rough to the touch if not covered or further processed.
• These braids can be formed into secondary shapes, such as coils that have little or no inherent secondary shape, they can be dimensioned to engage the walls of the aneurysm, or they can have other shapes (e.g. random,“flower”, or three dimensional).
• These structures can also have a fiber bundle(s) in, or protruding from, the interior core made of natural fibers or thermoplastics infused with drugs to help with clotting (see, e.g., U.S. Pat. No. 5,423,849 to Engelson et al.; and U.S. Patent No. 5,645,558 to Horton).
• Coiled braids can also be supplied with bio-active or other surface coatings (see, e.g., U.S. Pat. No. 6,299,627 to Eder et al.).
• Non-expandable braids can also cover core or primary structures, such as coils or other braids (see, e.g., U.S. Pat. No. 5,382,259 to Phelps et al.; U.S. Pat. No. 5,690,666 to Berenstein et al.; U.S. Pat. No. 5,935,145 to Villar et al.; and U.S. Pat. No. 8,002,789 to Ramzipoor et al.).
• these covers have open cell designs (e.g., inner coil structure is visible through the braid).
• Braids may also be self-expanding and can be shaped into various forms such as a ball, a coil(s), and a combination braid-stent.
• self-expanding devices are disclosed in the following: U.S. Pat. No. 8,142,456 to Rosqueta et al.; U.S. Pat. No. 8,361,138 to Adams; U.S. patent application Ser. No. 13/727,029 to Aboytes et al.; U.S. patent application Ser. No. 14/289,567 to Wallace et al.; U.S. patent application Ser. No. 13/771,632 to Marchand et al.; and U.S patent application Ser. No. 11/148,601 to Greenhalgh.
• Self-expanding braids are expected to occupy all or substantially all of the volume of an aneurysm to obstruct flow and/or promote endothelization at the neck.
• a major problem for these designs is sizing.
• the implant has to be accurately sized so that upon expansion it occupies enough volume to fill the entire aneurysm, dome to neck. Undersized devices lead to insufficient packing as described above, whereas oversizing risks rupturing the aneurysm or blockage of parent vessel.
• Neck bridges are yet another approach to treating intracranial aneurysms.
• Neck bridges that support the coil mass tend to be petal/flower shaped and span the neck of the aneurysm or placed between the parent vessel and aneurysm sac. Examples of neck bridges for supporting the coil mass are disclosed in the following: U.S. Pat. No. 6,193,708 to Ken et al.; U.S. Pat. No. 5,935,148 to Villar et al.; U.S. Pat. No. 7,410,482 to Murphy et al.; U.S. Pat. No. 6,063,070 to Eder; U.S. patent application Ser. No. 10/990,163 to Teoh; and U.S. Pat. No. 6,802,851 to Jones et al.
• Neck bridges that obstruct flow through the aneurysm neck can be deployed either internal or external to the aneurysm and may not require deployment of embolization coils.
• Examples of intra-aneurysmal neck bridges with deployment at the base of the aneurysm sac with components extending into the neck are disclosed in U.S. Pat. No. 6,454,780 to Wallace; U.S. Pat. No. 7,083,632 to Avellanet et al.; U.S. Pat. No. 8,292,914 to Morsi; and U.S. Pat. No. 8,545,530 to Eskridge et al.
• Examples of neck bridges deployed external to the aneurysm (in the parent vessel) are disclosed in U.S. Pat No.
• Neck bridges can also have surface treatment to encourage neointima formation as disclosed in U.S.
• Stents and flow diverters are similar to neck bridges in function, but are intended for parent vessel reconstruction and therefore run distal to proximal of the aneurysm, covering the neck. Such devices are deployed in the parent vessel and are intended to act as a physical blood flow barrier to induce sac embolization, stabilize embolic coils, and prevent coil protrusion and/or migration.
• Flow diverters due to their relative low porosity (high coverage), can be used with or without coils and have been found to promote thrombus formation by restricting blood flow into the aneurysm sac.
• complications such as recanalization, delayed stent thrombosis, delayed aneurysm rupture, and stent migration have also been observed.
• An example of a stent is disclosed in U.S. Pat. No. 6,746,475 to Rivelli and a flow diverter is disclosed in U.S. Pat. No. 8,398,701 to Berez et al.
• a balance needs to be achieved in the overall device between the stiffness of the device to maintain its heat set shape and the softness/flexibility of the device to avoid damage to the vasculature and to enhance aneurysm packing. Additionally, in manufacture, in attaching the components of the device, a balance needs to be maintained between sufficient stiffness and flexibility. To date, no device effectively achieves this along with the other objectives enumerated above, with current devices at best achieving one objective at the expense of the others.
• the present invention overcomes the problems and deficiencies of the prior art as it provides an implant with an optimal balance of the foregoing objectives.
• an implant for inducing blood stagnation in an intracranial aneurysm of a patient comprising an outer expandable structure and an inner absorbent textile structure.
• the outer structure contacts one or both of the wall or neck of the intracranial aneurysm and is movable from a reduced profile position for delivery to an expanded placement.
• the inner absorbent textile structure is positioned within the outer structure, the inner textile structure including a plurality of yams which are formed from a plurality of filaments.
• the filaments of the yams have spaces therebetween to induce flow of blood between the filaments of the yam to transport blood along the yams, and the yams are formed into a permeable structure to allow inflow of blood between the yams and through the implant, the implant becoming saturated with blood to cause stagnation of blood and blood clotting.
• the outer structure is partially wrapped around the inner structure.
• the outer structure forms a lattice structure to form a scaffold for tissue.
• the outer structure is an open cell braided structure.
• the outer structure can in some embodiments be a metallic structure having struts and openings between stmts.
• the inner structure can include one or more radiopaque elements.
• the inner structure in some embodiments is tubular with a lumen extending longitudinally therein for receipt of blood and a capillary effect is created within the implant when the inner structure is exposed to blood such that blood is transported in a proximal direction through the lumen.
• the spaces between the plurality of filaments create a first capillary effect and the plurality of yams have a set of pores forming the permeable structure for absorption of blood to create a second capillary effect.
• a core element having a lumen for receiving blood is positioned within the inner structure and attached to the inner structure.
• an implant for inducing blood stagnation in an intracranial aneurysm of a patient comprising an outer structure for contacting one or both of a wall or neck of the intracranial aneurysm and an inner absorbent permeable textile structure positioned within the outer structure.
• the outer structure forms a lattice structure and is movable from a reduced profile position for delivery to an expanded placement position.
• the textile structure induces flow of blood along and into the textile structure, the implant becoming saturated with blood to cause stagnation of blood and blood clotting.
• the outer structure is an open cell braided structure. In some embodiments, the outer structure is a mesh. In some embodiments, the outer structure is composed of a metallic material.
• the inner structure in some embodiments is a tubular braid. In some embodiments, the inner structure is assembled from a plurality of electrospun filaments.
• the inner structure can include in some embodiments a radiopaque inner coil positioned within the textile structure and having a lumen extending therein.
• an implant for inducing blood stagnation in an intracranial aneurysm of a patient comprising an absorbent textile structure including a plurality of yams, the yams formed from a plurality of filaments, the filaments of the yams having spaces therebetween to induce flow of blood between the filaments of the yams to transport blood along the yams, and the yams formed into a permeable structure to allow inflow of blood between the yams and through the implant, the implant becoming saturated with blood to cause stagnation of blood and blood clotting.
• a mesh for contacting one or both of a neck or wall of the intracranial aneurysm is positioned around a least a first portion of the textile structure leaving a second portion of the textile structure exposed.
• the mesh is self-expandable to move from a reduced profile position for delivery to an expanded placement position and the textile structure is non self-expandable.
• a radiopaque structure is positioned on one or both of a proximal end and a distal end of the textile structure.
• a radiopaque coil is positioned within the textile structure and attached to the textile structure forming a core element with a lumen therein for receiving blood.
• an implant for inducing blood stagnation in an intracranial aneurysm by placement at the bifurcation adjacent the aneurysm comprising a support movable from a reduced profile position for delivery to an expanded placement position within the vessel adjacent the intracranial aneurysm.
• An absorbent textile structure is positioned at a distal end of the support and forms an open umbrella like structure.
• the textile structure includes a plurality of yams, the yams formed from a plurality of filaments, the filaments of the yams having spaces therebetween to induce flow of blood between the filaments of the yam to transport blood along the yams, and the yams formed into a permeable structure to allow inflow of blood between the yams and through the implant, the implant becoming saturated with blood to cause stagnation of blood and blood clotting.
• the support is composed of metallic stmts. In some embodiments, the support is positioned outside the aneurysm and the inner structure is positioned at the neck of the aneurysm. In some embodiments, the textile structure includes one or more radiopaque elements.
• an implant for inducing blood stagnation in an intracranial aneurysm comprising an absorbent textile structure and a support movable from a reduced profile position for delivery to an expanded placement position within the neck of the intracranial aneurysm.
• the support includes a plurality of radially extending fingers with ends facing into the aneurysm.
• the absorbent textile structure is attached to a distal end of the support.
• the textile structure includes a plurality of yams, the yams formed from a plurality of filaments, the filaments of the yams having spaces therebetween to induce flow of blood between the filaments of the yam to transport blood along the yams, and the yams formed into a permeable structure to allow inflow of blood between the yams and through the implant, the implant becoming saturated with blood to cause stagnation of blood and blood clotting.
• the support has a cup shape.
• an implant for inducing blood stagnation in an intracranial aneurysm comprising an absorbent textile structure.
• the textile structure includes a plurality of yams formed from a plurality of filaments, the filaments having spaces therebetween to induce flow of blood between the filaments of the yam to transport blood along the yams, and the yams formed into a permeable structure to allow inflow of blood between the yams and through the implant, the implant becoming saturated with blood to cause stagnation of blood and blood clotting.
• a wire strand extends within the textile structure to add rigidity to the textile structure.
• the present invention also provides in some aspects methods for filling and infusing an intra-aneurysmal micrograft with blood or another liquid and delivering it to an intracranial aneurysm.
• Figure 1 is a side view partial cut away of an intra-aneurysmal micrograft in accordance with one embodiment of the present invention
• Figure 2A is a view of another embodiment of the intra-aneurysmal micrograft of the present invention having a larger diameter and thinner wall;
• Figure 2B is a side view similar to Figure 2A except showing the micrograft stretched to highlight the peaks and valleys;
• Figure 2C is a side view of the micrograft of Figure 2A in a bent placement position
• Figure 3A is a side view of another embodiment of the intra-aneurysmal micrograft formed into a helical shape
• Figure 3B is a side view of another embodiment of the intra-aneurysmal micrograft having a flared end to be directed by blood flow;
• Figure 4A is a side view partial cut away of an intra-aneurysmal micrograft in accordance with another embodiment of the present invention.
• Figure 4B is an enlarged view of a proximal end of the micrograft of Figure 4A;
• Figure 4C is side view of a proximal end of an alternate embodiment of the micrograft of the present invention.
• Figure 4D is a cross-sectional side view of the micrograft of Figure 4A placed over a mandrel before crimping;
• Figure 4E is a cross-sectional side view of the micrograft of Figure 4A after crimping
• Figure 4F is a cross-sectional view of the micrograft of Figure 4A showing the entire micrograft
• Figure 4G is a cross-sectional view similar to Figure 4F showing an alternate embodiment of the micrograft
• Figure 4H is side view of the proximal portion of the micrograft of Figure 4A with an alternate tube;
• Figure 41 is a bottom perspective view of the micrograft of Figure 4A with the braid cut to illustrate the inner coil;
• Figure 4J is a front perspective view showing the inner coil within the braid
• Figure 4K is a perspective view of the micrograft of Figure 4 A formed in a secondary helical configuration
• Figure 4L is a close up view of a transverse cross-section of the filaments of Figure 4 A;
• Figure 4M is a close up view of the braid of Figure 4A;
• Figure 4N is a side view similar to Figure 4F showing an alternate embodiment of the micrograft with a longer fuse joint
• Figure 40 is a side view similar to Figure 4F showing an alternate embodiment of the micrograft with a fuse joint spaced from a distal end of the coil;
• Figure 4P is a side view similar to Figure 4F showing an alternate embodiment of the micrograft with a non-continuous fuse joint
• Figure 4Q is a side view similar to Figure 4F showing an alternate embodiment of the micrograft with a fuse joint at the proximal tube and proximal windings of the inner coil
• Figure 5A is a side view of an intra-aneurysmal micrograft delivery system in accordance with an embodiment of the present invention.
• Figure 5B is a side view of the delivery wire and mounted micrograft of Figure 5A;
• Figure 5C is an enlarged partial cross-sectional view of the intra-aneurysmal micrograft of Figure 5B showing the mating of the micrograft with the taper of the delivery wire;
• Figure 5D is a side view of the pusher catheter of Figure 5A without the delivery wire;
• Figure 5E is a side view of an alternate embodiment of the micrograft delivery system of the present invention.
• Figure 5F is an enlarged cross-sectional view of a portion of the delivery system of Figure 5E shown in the locked position;
• Figure 5G is view similar to Figure 5F showing the delivery system in the unlocked position
• Figure 5H is a view similar to Figure 5G showing the delivery system withdrawn and the micrograft fully deployed;
• Figure 6 is a side view of a rapid exchange pusher catheter for micrograft delivery in accordance with another embodiment of the present invention.
• Figure 7 is a side view of another embodiment of the intra-aneurysmal micrograft delivery system of the present invention having a pusher wire with locking arms;
• Figure 8 is a side view of another embodiment of the intra-aneurysmal micrograft delivery system of the present invention using a stent or flow diverter to push the micrograft;
• Figure 9 is a side view of an intra-aneurysmal micrograft introducer system in accordance with another embodiment of the present invention.
• Figure 10 is a side view illustrating the loading of an intra-aneurysmal micrograft delivery system of Figure 5 A into a microcatheter;
• Figures 11 A, 11B, 11C, 11D, 11E and 1 IF illustrate delivery of an intra- aneurysmal micrografl into an intracranial aneurysm in accordance with an embodiment of the present invention wherein:
• Figure 11 A shows the delivery wire inserted into the aneurysm sac
• Figure 11 B shows initial advancement of the micrograft into the intracranial aneurysm after removal of the wire
• Figure 11 C is an enlarged cross-sectional view of the micrograft exiting from the catheter corresponding to the position of Figure 1 IB;
• Figure 11 D shows the micrografl fully deployed from the catheter and positioned in the intracranial aneurysm
• Figure 11E is an enlarged cross-sectional view of the deployed blood- filled micrograft corresponding to the position of Figure 1 ID;
• Figure 1 IF shows multiple micrografts of Figure HE positioned in the intracranial aneurysm sac
• Figures 12 A, 12B and 12C illustrate directed delivery by the delivery wire of an intra-aneurysmal micrograft into an aneurysm in accordance with an embodiment of the present invention
• Figure 13 illustrates delivery of smaller length flow directed intra-aneurysmal micrografls into an intracranial aneurysm in accordance with another embodiment of the present invention
• Figure 14 illustrates delivery of the delivery wire carrying the intra-aneurysmal micrografl through cells of a stent or flow diverter into an aneurysm in accordance with another delivery method of the present invention
• Figure 15 illustrates delivery of an intra-aneurysmal micrografl into an aneurysm using a delivery wire with the arms of Figure 7;
• Figure 16A is a photograph of an uncrimped tubular PET braid alongside a crimped braid of the present invention to show a wave-like profile as in Figure 1 A;
• Figure 16B is a photograph of a crimped micrografl braid alongside a crimped micrografl braid that has been heat set into a coiled shape in accordance with an embodiment of the present invention
• Figure 16C illustrates a micrograft tubular body of the present invention partially filled with a fluid to illustrate the capillary effect.
• Figure 17 is a photograph of one end portion of the micrograft of Figure 1A;
• Figures 18A and 18B are flowcharts summarizing alternate methods of placing and deploying a micrograft of the present invention
• Figure 19 is a flowchart summarizing viscosity lock function in accordance with an embodiment of the present invention.
• Figure 20A is a side view of an alternate embodiment of the delivery system of the present invention.
• Figure 20B is a side view of another alternate embodiment of the delivery system of the present invention.
• Figure 21 A is a side view of another alternate embodiment of the delivery system of the present invention shown interlocking with a micrograft of the present invention
• Figure 21B is a top view of the delivery system and micrograft of Figure 21 A;
• Figure 22A is a side view of another alternate embodiment of the delivery system of the present invention shown interlocking with a micrograft of the present invention
• Figure 22B is a cross-sectional view taken along line A-A of Figure 22A;
• Figure 22C is a top view of the delivery system and micrograft of Figure 22 A;
• Figure 23A is a side view of another alternate embodiment of the delivery system of the present invention.
• Figure 23B is a side view of the delivery system of Figure 23A interlocking with a micrograft of the present invention
• Figure 24 is a side view of another embodiment of the delivery system of the present invention delivering a micrograft and a flow diverter;
• Figures 25A, 25B, 26A, 26B, 27A, 27B, 28A and 28B show a comparison of the braid before and after crimping (the inner coil removed for clarity) wherein Figures 25A and 26A are close up views of the braid prior to crimping and Figures 25B and 26B are close up views of the braid after crimping, Figure 27A is a transverse cross-sectional view of the braid prior to crimping and Figure 27B is a transverse cross-sectional view of the braid after crimping, and Figure 28A is a perspective view of the braid before crimping and Figure 28B is a perspective view of the braid after crimping; Figure 29 is a side view of an alternate embodiment of the present invention showing a double braid attached at the proximal end;
• Figure 30 is a side view of an alternate embodiment of the implant of the present invention having a tubular braid within a self-expanding structure;
• Figure 31 is a side view of another alternate embodiment of the implant of the present invention having an expandable mesh partially wrapped around the tubular braid;
• Figure 32 is a side view of another alternate embodiment of the implant of the present invention having a tubular braid positioned partially within an expandable spherical structure;
• Figure 33 is a side view of another alternate embodiment of the implant of the present invention having a tubular braid positioned entirely within an expandable spherical structure;
• Figure 34 is a side view of an umbrella shaped tubular braid for use in bifurcated aneurysms
• Figure 35 is a side view of another alternate embodiment of the implant of the present invention having a metal braid inside the tubular braid and shown in the stretched position for delivery;
• Figure 36 is a side view of the implant of Figure 35 in the non-stretched condition
• Figure 37 is a side view of another alternate embodiment of the implant of the present invention having a stiffening strand within the tubular braid.
• Figure 38 is an alternate embodiment of the implant of the present invention having a cup portion at the neck of the aneurysm.
• Figure 1 illustrates a partial cut away side view of an intra-aneurysmal micrograft for insertion into an intracranial aneurysm in accordance with one embodiment of the present invention.
• the micrograft of this embodiment designated generally by reference number 10, includes a biocompatible non-self-expandable absorbent braided polymeric textile tubular body 12 that has been crimped to reduce stiffness and increase wall thickness and fabric density.
• the micrograft 10 has sufficient stiffness as well as sufficient flexibility to provide the advantages described below. It further is structured to enable a triple capillary action to promote blood clotting as also discussed in detail below.
• the micrograft further preferably has a high surface area for increased blood absorption, is radially deformable, has a low friction surface for ease of delivery and can be shape set to enhance packing of the aneurysm. These features and their advantages are described in more detail below. Note the micrografts of the present invention are especially designed to induce blood stagnation or clot to rapidly treat the aneurysm.
• micrografts are configured for delivery to an intracranial aneurysm, although they can be utilized for occlusion in other aneurysms in other areas of the body as well as for occlusion in other vascular regions or in non-vascular regions.
• An over the wire delivery system is provided to deliver the micrograft of the present invention to the aneurysm. Variations of these delivery systems of the present invention are discussed in detail below. Preferably, multiple micrografts are delivered so that the aneurysm sac is densely packed.
• the preferred tubular body 12 of micrograft 10 is constructed of substantially 100% 20 denier/18 filament polyester (e.g., PET) multi- filament interlaced yams, but can be made of other combinations of denier and filament such as 10 denier/ 16 filament yam, or 15 denier/ 16 filament yam, for example. That is, each yam is composed of a plurality of polyester filaments having pores or spaces therebetween, and the plurality of yams also have pores or spaces therebetween, for reasons described below.
• PET 20 denier/18 filament polyester
• each yam is composed of a plurality of polyester filaments having pores or spaces therebetween, and the plurality of yams also have pores or spaces therebetween, for reasons described below.
• the tubular body has a proximal end 14 and a distal end 16, with proximal defined as closer to the user and distal defined as further from the user such that the distal end is inserted first into the aneurysm. Blood then flows through the micrograft 10 in a distal to proximal direction.
• the tubular body 12 has a preferred inner diameter in the range of about 0.001 inches to about 0.068 inches, and more narrowly in the range of about 0.006 inches and about 0.040 inches, for example about 0.008 inches.
• It has a length ranging from about 2 mm up to about 150 cm and a preferred outer diameter in the range of about 0.002 inches to about 0.069 inches, more narrowly in the range of about 0.010 inches to about 0.041 inches, for example about 0.010 to about 0.020 inches. Note that although these ranges and dimensions are the preferred ranges and dimensions, other ranges and dimensions are also contemplated. These dimensions provide a sufficiently small size micrograft so that the micrograft can be navigated to and into the cranial vasculature for placement within a cranial vessel.
• Each of the multi-filament yams are made of multiple wettable micro-filaments, or fibers, assembled with spaces (pores) between them, referred to as inter-fiber spaces or pores.
• the pores are sufficiently sized to induce capillary action when contacted by a liquid, resulting in the spontaneous flow of the liquid along the porous yam (i.e., wicking).
• This capillarity between fibers (intra-fiber) within the yam is termed as “micro-capillary” action.
• a sufficiently wettable and porous yam will have high wickability and transport liquid along its length.
• the multiple filaments also provide a high surface area and can be hydrophilic or hydrophobic.
• This assembly of the two or more wickable multi-filament yams into a permeable structure results in a“macro-capillary” action, i.e., the transporting of liquid between the yams and throughout the structure.
• a“macro-capillary” action i.e., the transporting of liquid between the yams and throughout the structure.
• Such yams and/or fibers can be textured, flat, twisted, wettable, non-wettable, with beads, of various cross-sections (tri- lobal, multi-lobal, hollow-round, etc.), coated or having a modified surface, composite, reticulated, porous, pre-shrunk, crimped or modified using similar heat treatment or chemical processes.
• the multi-filament yams can be assembled into a textile tubular structure using a braider or other textile manufacturing equipment and methods.
• the braider can be set-up with a program or recipe, spools of multi-filament yam and an optional core mandrel to braid over. Anywhere from about 8 to about 288 strands of multi-filament yam may be used to form the tube, depending on the desired final structural properties such as density, picks per inch (PPI), porosity, compliance, etc.
• multiple braiders or a braider in combination with a coil winder can be run simultaneously to form a braid over braid or braid over coil design.
• the vascular graft (micrograft) has a proximal opening at the proximal end and a distal opening at the distal end for blood flow into the distal end and through the lumen, (the proximal and distal openings aligned with a longitudinal axis), thereby forming a conduit for transport of blood through the continuous inside lumen (inside diameter).
• a capillary effect is created within the vascular graft when the biocompatible structure is exposed to blood such that blood is transported in a proximal direction through the distal opening in the vascular graft and through the vascular graft wherein blood clots.
• the vascular graft retains blood, and becomes saturated with blood, to promote clotting.
• the outer member, i.e., the textile structure, as disclosed herein is configured as a tubular member for flow therein, functioning as a capillary tube.
• the tubular textile member is configured in a closed cell fashion so as to form a tube for flow therethrough, i.e., the lumen inside the textile structure is sufficiently small to enable function as a capillary tube, but the textile structure still has sufficient sized openings/spaces for absorbing blood through and along the yams and filaments as described herein.
• a continuous wall continuously inner diameter is formed along the length of the textile structure to retain blood while also maintaining small spaces (micro-capillaries) in between fibers to wick and absorb blood.
• This closed cell or tight textile, e.g., braided, structure is maintained in the non-expanding embodiments disclosed herein since the diameter of the textile structure (and thus the diameter of the vascular graft) does not change from the delivery to implant positions. That is, the textile structure is non-expanding such that when it is delivered to the aneurysm its outer diameter X is equal to its outer diameter X when positioned within the delivery member.
• the closed cell structure of the embodiments disclosed herein forms such small openings that the inner element, i.e., the core element, covered by the textile structure is not visible through the outer textile structure.
• the tubular textile structure (which forms a braid in some embodiments) forms a continuous circumferential wall along a length without large spaces between the filaments and/or yams.
• This continuous wall is shown in the tight spacing of Figures 4A-4D and thus creates a continuous outer member (low porosity wall) to contain and direct flow.
• the use of large open pores between filaments would result in an outer member (outer textile structure) with a non-continuous wall that would allow blood to pass radially through the large pores or gaps between strands of the textile structure (forming a highly porous wall) so the structure will not contain or direct blood flow and thus capillary action (effect) will not take place nor will it behave like a vascular graft that transports blood therethrough.
• the yams of the textile structure in preferred embodiments are close enough to form a continuous wall to wick and transfer blood via the wall and inside lumen.
• Capillary action can be defined as the ability of liquid to fill fine gaps or voids with wettable walls driven by capillary forces that arise from wetting of the walls (e.g., fiber surface). Wettability, or wetting, is the ability of a solid surface to attract a liquid in contact with it such that it spreads over the surface and wets it. Wickability, or wicking, is the spontaneous flow of a liquid driven by capillary forces. Capillary flow through a textile medium is due to a meniscus (wetting) formed in microscopic, inter-connected voids between fibers and yams. Wicking in a textile or fibrous medium can only occur when a liquid wets fibers assembled with capillary spaces between them.
• a structure experiencing capillarity is constructed of wettable fibers with sufficiently small, inter-connected gaps. Since the textile structures disclosed herein are composed of wettable yams and the yams are made up of wettable fibers, which wick blood, capillary flow in such a wall structure of the textile structure can be considered as the filling of capillary spaces between fibers within a yam (inter-fiber) and between yams (inter-yam) in the wall of the textile structure.
• the capillary spaces formed between yarns can be termed as macro-capillary and capillary spaces formed between individual fibers of a yam may be termed microcapillary as described herein.
• the capillary action occurs as the yams making up the wall of the textile structure and the fibers making up the yams are assembled close enough, as shown for example in Figures 4A and 4M, to create microcapillaries that induce wicking as in the textile structure of the vascular grafts disclosed herein.
• the tubular textile structure of embodiments disclosed herein utilizes the three capillary actions (i.e., inside (inner) lumen, inter-yam and inter-filament capillary actions) to act as a capillary tube and also achieves blood retention inside the tubular structure.
• capillarity is dependent on pore size, meaning gaps in the textile structure have to be sufficiently small to initiate capillary flow (i.e., smaller pores or spaces result in better wicking).
• the textile structure will not induce capillary action if there is excessive porosity of the textile structure.
• the vascular graft of the present invention advantageously promotes blood clotting, i.e., induces blood stagnation or clot to rapidly treat the aneurysm. This is achieved in part by the construction of the vascular graft holding blood therein once blood permeates the graft.
• the blood in some embodiments permeates the graft when still held by the delivery member and positioned in the aneurysm.
• portions of the inner surface of the inner wall of the textile structure are in contact with the inner element.
• these contact portions can be end portions.
• these contact portions can be the areas of the valleys of the crimped textile structure.
• Other intermittent contact portions are also contemplated.
• Current embolic coils require an internal stretch-resistant member to prevent stretching or unraveling during use.
• an internal stretch resistant member is not necessary since the risk of unwinding or unraveling of the internal element, e.g., radiopaque coil, is not present since the textile structure provides stretch resistance.
• the implant structure of the implants disclosed herein can be devoid of such additional internal stretch resistant member(s).
• the absence of such stretch resistant member inside the structure also, for use in some applications, provides an obstruction- free lumen so as not to interfere or inhibit blood flow through the distal end and through the lumen of the vascular graft.
• the micrograft 10 is braided over the core mandrel which sets the internal diameter (ID) of the braid.
• the core mandrel can be made of a variety of materials such as metal, wire, polymers or other textile fibers. It can also be formed of a stretchable material to aid in removal during manufacturing.
• the micrograft 10 in preferred embodiments can also include a permanent core element such as shown in the embodiment of Figure 4 A discussed below.
• the core element can be made of a variety of materials, and can itself be formed of one or more filaments, and may optionally be coated.
• the core element is formed of a metal coil having a lumen therein. It can be composed of platinum- tungsten or other materials.
• the braid and coil can be heat set at a temperature that would not damage or disintegrate the braid.
• the braiding process may be adjusted for the highest PPI possible so as to produce a tightly interlaced, dense braid without tenting (braiding over itself or overlapping). However, in some cases tenting may be desirable to produce a useable feature such as a braid bulge or ring for locking or wall thickening.
• the braid while still mounted on the core mandrel, may be heat treated after manufacturing to set the braid structure, including PPI, and to relieve filament stresses produced during braiding.
• the preferred PPI for the as-braided therapeutic structure may range from about 80 to about 200 PPI for a 16 strand braid, and more narrowly in the range of about 120 to about 180 PPI, preferably about 167 PPI.
• the PPI is dependent on the number of strands used to braid, the braid angle, and the braid diameter, such that a braided tube of a given diameter with 120 PPI and 16 strands would have a PPI of 60 when braided using 8 strands at the same diameter (assuming all of the variables constant).
• the preferred PPI should be high enough to produce a dense interlacing pattern, but not so high as to interfere with core mandrel removal, unless the core is stretchable.
• Crimping which will be discussed later in detail, may be used to increase PPI (and braid angle), once again depending on final structural requirements.
• the use of multi-filament yams in combination with a relatively high PPI of the present invention results in a somewhat stiff, relatively small or closed cell (high pick density) braided tube.
• high pick density high pick density
• a third capillary effect is created.
• this third capillary effect is responsible for spontaneous flow of liquid inside the micrograft lumen, e.g., within the lumen of the braid, in a proximal direction.
• the third capillary effect is through either or both a) the lumen of the inner element which is in the lumen of the braid so the capillary effect is within the braid lumen; or b) in the gap between the inner diameter of the tubular braid and the outer diameter of the inner element.
• the liquid can also spread in other directions as it is absorbed.
• This structure thus results in a soft capillary tube that has absorbent walls.
• This triple capillary effect is beneficial for a vaso-occlusive device due to the fact that the yams, the fibrous wall, and the micrograft lumen can become saturated with blood. Since blood absorbed by the micrograft is trapped within the structure, it becomes stagnant and will quickly thrombose or form clot.
• the inner diameter is preferably about .003” to about .012”, and more preferably about .007”.
• the micrograft 10 achieves an optimal balance of porosity and fluid containment within the same structure. This is achieved by controlled interlacing of microporous yams that allow blood wicking and cell ingrowth. When braided with sufficiently high PPI and tension, for example, the porous yams are able to form a fluid barrier that maintains a degree of permeability.
• the resultant structure is an assembly of micro-porous yams that may be interlaced with sufficient density to form a fluid-tight tubular capillary. This interlacing of the yams or assembly of filaments can be achieved using textile manufacturing processes, such as weaving, knitting, or electrospinning.
• Porous or semi-porous filaments may also be used in place of multi-filament yams to achieve desired absorbency.
• the micrograft structure does not have to include a clearly defined inside lumen to maintain capillarity, e.g., a defined lumen formed within the wall of the braid or core element, but may alternatively be a porous assembly of fibers sufficiently spaced to allow transport of liquid (much like a suture or string wicking liquid) or a porous scaffold or biocompatible open cell foam.
• the semi-porous micrograft 10 as formed as described above has the desired effect of aiding thrombus formation, it is also relatively stiff as a result of the filaments being closely packed or tightly braided as mentioned above.
• One benefit of a stiff, denser braid is its ability to retain its non-linear heat-set shape as compared with lower PPI (less dense) braids. This may facilitate the use of stiffer, higher density 3D shaped micrografts as framing-type devices used for initial filling of aneurysm circumference, and then soft and highly compliant micrografts may be used as fillers or “finishing” devices towards the end of the embolization procedure.
• a dense (or high PPI) 2x2 (two-over-two) configuration braid may be used as the initial“framing” device whereas a softer and more compliant braid having a lower-PPI 1x2 (l-over-2- under-2) configuration braid may be subsequently used to fill the framed space within the first device.
• excessive stiffness is an undesirable mechanical property for the microcatheter delivery because an overly stiff device may cause unwanted movement of the microcatheter tip during delivery which can adversely affect navigation of the microcatheter or damage vessels during advancement through the tortuous vasculature.
• Excessive stiffness is also an undesirable property because stiff devices will conform less to the configuration of the aneurysmal sac and thus prevent efficient aneurysm packing.
• the micrograft tubular body (braid) 12 is crimped during manufacture, i.e., longitudinally compressed and heat set.
• the braid 12 is compressed, axial orientation of the braided strands is reduced thereby increasing braid angle with respect to the longitudinal axis of the tubular body which reduces their influence on overall stiffness of the structure, much like a straight wire taking on a more flexible form when coiled.
• Crimping will also effectively increase the PPI, wall thickness, and linear density of the braid by axially compressing the structure and filament bundles. This compression causes an outward radial expansion and an increase in wall thickness of the tube.
• the resulting braid is much more deflectable, has reduced bend radius, a higher density and up to 2x to 3x or higher increase in PPI, depending on braid structure and compressive force applied.
• This axial compression also causes the braid structure to“snake” or produce a spiral wavy form as shown in Figure 1, which as viewed from the side is a series of macro peaks and valleys, termed“macro-crimps” in a sinusoidal shape.
• the sinusoidal undulations are typically more pronounced in braid structures where the ratio of wall thickness to overall braid diameter is larger (i.e., overall diameter decreases).
• Sufficient crimping may also re-orient individual yam fiber bundles from a mostly flattened (longitudinally organized cross-section) state to a compressed (transversely organized cross-section) state.
• micro-crimps This increases surface unevenness of the braid since individual yams bulge outward and produce micro peaks and valleys on the braid surface, termed“micro-crimps” (see Figure 4B and 25B for example) with the peaks 17 located at the height of the yam and the valleys 19 between adjacent yams.
• the braid can have a series of coaxial aligned filaments and compressed so the filaments orient substantially transversely (with respect to a longitudinal axis of the mandrel).
• Different braid patterns may also produce varied results when crimped.
• a lxl braid structure will tend to have a more uniform tubular shape and less distinctive macro-crimp pattern
• a 1x2 braid structure will produce a more sinusoidal (macro peaks and valleys) crimped structure in addition to the micro peaks and valleys (micro-crimps) of individual fiber bundles.
• These structural changes result in an ultra-deflectable, increased density, wavy-wall structure having macro-peaks 18 and valleys 20 as shown in the sinusoidal shape of Figure 1.
• crimping Besides increasing braid flexibility, PPI and/or wall thickness, varying amounts of crimping imparts other potentially desirable features such as kink and crush resistance, reduced bend radius, as well as increased surface area per unit length via accordion-like compression of the wall (i.e., forming peaks and valleys).
• the uneven texture of crimped peaks and valleys also helps create localized hemodynamic turbulence and flow stagnation, resulting in improved thrombus formation.
• the crimps make the device more compliant, easily deflectable and conformable which facilitates packing confined spaces or voids in the vasculature, e.g., the aneurysm. Crimping may also be used to vary wicking and permeability of the textile wall since it reduces fabric porosity and increases yam tortuosity.
• the location, amount and magnitude of crimping can be controlled to impart different amounts of flexibility and elongation to the structure to achieve its desired characteristics. For example, extreme crimping can be applied so the braid is compressed until the individual fibers within each yam bundle come together and cannot compress any further, giving the braid some rigidity and improving pushability through a microcatheter lumen. Other factors that impact crimping and the resulting longitudinal pattern are fiber diameter and stiffness, yam tension during braiding, wall thickness, wall porosity (PPI), number of filaments, and mandrel diameter.
• PPI wall porosity
• larger diameter, thin walled tubular bodies may show macro peaks and valleys which are more dense and visible than small, thick walled crimped tubes.
• Figures 2A-2C show an example of such large diameter thin walled tube where crimping can form an accordionlike folds or pleat structure rather than a sinusoidal configuration as the peaks are closer together.
• Crimping smaller diameter braids typically induces a wave-like, sinusoidal longitudinal (macro) contour that is larger in comparison to overall diameter and increases wall thickness of the structure, as shown in Figure 16A and 28B.
• the sinusoidal contour is typically three-dimensional in form (like a spiral) and is visible from all sides of the braid.
• the ends of the tubular body may also be rotated/twisted relative to each other and then heat set as another method to impart deflectability to the tubular body.
• the crimps are produced by compressing the textile tubular structure axially to reduce length and thereby produce a longitudinally extending wavy shape.
• the crimping reduces an axial orientation of the fibers to increase a braid angle and increase a linear density and wall thickness by axially compressing the biocompatible tubular structure, and forms a series of alternating peaks and valleys along a length of a surface of a wall, i.e., in a longitudinal direction along the longitudinal axis, to form a longitudinally extending wavy sinusoidal shape.
• crimping can increase the braid angle by at least 5 degrees.
• crimping can increase the braid angle by between 1 and 4 degrees.
• the braid angle precrimping can be between 1 degree and about 40 degrees and the post crimping angle can be between about 35 degrees and 90 degrees. Other angles are also contemplated.
• the braid 10 can also be made more flexible by varying the braid angle or PPI, by reducing yam tension, by adding cuts/slits, changing the number of filaments or strands, or heat setting repeating patterns along its length (such as flat sections or kinks). If a stiffer tube is desired, denser yam and/or braid pattern may be used or crimping decreased. Additionally, the micrograft structure may incorporate a coaxial construction (i.e., having a graft inside a graft) or multi-ply or multi-lumen wall design, especially when using fine-denier textiles.
• Intra-luminal braid inserts such as the coils mentioned above, may also be composed of, or coated with, a highly wettable/hydrophilic material to enhance the capillary effect.
• the micrograft may be coaxially assembled with a secondary braid or internal coil structure that is highly hydrophilic and/or radiopaque, while maintaining the therapeutic external surface.
• the tubular body 12 may be braided, woven or knitted, partially or completely, from monofilaments or multi-filament yams, strands, sutures, microfibers, or wire that is synthetic, semi-synthetic, natural or thermoplastic.
• Such materials may include, but are not limited to, Dacron, poly ester amide (PEA), polypropylene, olefin polymers, aromatic polymers, such as liquid crystal polymers, polyethylene, HDPE (high density polyethylene), ultra-high-molecular-weight polyethylene (UHMWPE, or UHMW), polytetrafluoroethylene (PTFE), ePTFE, polyethylene terephthalate (PET), polyether ketone (PEK), polyether ether ketone (PEEK), poly ether ketone ketone (PEKK), nylon, PEBAX, TECOFLEX, PVC, polyurethane, thermo plastic, FEP, silk, and silicone, bio- absorbable polymers such as polyglycolic acid (PGA), poly-L-gllycolic acid (PLGA), polylactic acid (PLA), poly-L-lactic acid (PLLA), polycaprolactone (PCL), polyethyl acrylate (PEA), polydioxanone (PDS) and pseudo
• Metallic, metallic alloy or radiopaque material may also be included, Such material may be in the form of strands or filaments and may include, for example, platinum, platinum alloys (platinum-iridium or platinum-gold, for example), a single or multiple stainless steel alloy, nickel titanium alloys (e.g., Nitinol), barium sulfate, zinc oxide, titanium, stainless steel, tungsten, tantalum, gold, molybdenum alloys, cobalt- chromium, tungsten-rhenium alloys.
• platinum platinum alloys (platinum-iridium or platinum-gold, for example)
• nickel titanium alloys e.g., Nitinol
• barium sulfate zinc oxide
• titanium stainless steel
• tungsten tungsten
• tantalum gold
• molybdenum alloys cobalt- chromium
• tungsten-rhenium alloys cobalt- chromium, tungsten-rhenium alloys.
• the textile structure is formed of fibers of nonabsorbable material such as the non-absorbable materials (materials which do not have a medical indication for the material to be absorbed into the tissues or absorbed by the human body) listed above.
• tubular body may have an impact on the capillary effects discussed earlier.
• a change in material or construction methods may result in a simple capillary tube with capillary flow restricted to only the inner lumen of the tube, and not the walls.
• strands or filaments may be braided, interwoven, knitted, or otherwise combined to form a fabric or textile structure.
• the micrograft 10 of Figure 1 has a tubular body 12 with a proximal end 14 and a distal end 16.
• the micrograft 10 can include radiopaque structures such as radiopaque marker bands 22 which are inserted into the ends of the micrograft 10.
• Figure 17 is a picture of an end of micrograft 10 with such marker band.
• the marker bands which can also be in the form of coils or spheres, can be made from tantalum, platinum, platinum alloys (e.g., platinum- iridium alloy), gold, tungsten, or any suitable radiopaque material such as radiopaque polymer.
• the marker bands 22 are preferably approximately 1 mm or less in length and can be either of a sufficient inner diameter to slide over tubular body 12 or of a smaller diameter to fit inside the tubular body 12.
• Figure 1 shows an example of the marker bands 22 fit inside the tubular body and the marker bands 22 can be secured by melting of the braid over the bands (the melted fiber) at region 24, or attached by gluing.
• the bands 22 can also be undersized and sliced lengthwise so that they can be swaged or folded over the outside of tubular body 12, or tubular body 12 can be stretched so that undersized bands can be slid over the stretched/compressed length in order to attach the bands 22 to the tubular body 12.
• the bands can be flared at one end.
• a radiopaque fiber can be utilized to connect the bands, and the radiopaque fiber incorporated into the textile structure, or placed inside the tube.
• the bands can be composed of metal, or alternatively of a non-metallic material such as radiopaque shrink tubing or polymer.
• the marker bands can be adhered to the tubular body 12 using adhesive, mechanically by swaging or winding directly on to the tubular body, or by heating (when possible) and melting one of the materials.
• the bands can alternatively be attached by being screwed onto or into the core element, e.g., a helical core element, as discussed below.
• radiopaque balls or spheres can be put inside the braid lumen to provide radiopaque structure. This provides the radiopacity while providing a less stiff, i.e., more deflectable, device.
• the balls or spheres can be spaced apart axially along the tubular braid, or alternatively one or more can be in contact with one another, and can be either as an addition to the radiopaque coil and/or marker bands or as an alternative.
• the coils and spheres can be made of the foregoing materials utilized for the marker bands.
• radiopacity can be obtained by coating, wetting, staining, or impregnating the micrograft with a radiopaque material such as contrast media solution or nanoparticles. This can be done in manufacturing or in the operating room as part of the clinical procedure.
• the fibers or yams themselves may be doped or impregnated or coated with radiopaque substances as described above.
• the micrograft may also contain a series of equally spaces radiodense inserts along its length, resulting in intermittent radiopacity which may be sufficient for visualization in clinical settings.
• bands 22 can also be used to indicate structural changes in tubular body 12, as a means to control fraying, or as an integral part of the delivery system (e.g., stop-collar) as will be better understood in the discussion below of the delivery of the micrograft.
• Nitinol structures that are made increasingly radiopaque can be utilized. These structures can be glued, melted over, sewn or otherwise attached to the proximal and/or distal ends of the micrograft, either on the inner or outer diameter, and/or attached along a length of the tubular body. Sections of the micrograft or meltable/fusible sleeves of a braided polymer may also be heated and used to adhere bands or other radiopaque structures (components) to the micrograft. Bands or other radiopaque components can alternatively be attached by screwing into the coil windings inside the braid as discussed in more detail below. The bands or other radiopaque components can either be self-expanding or non-self-expanding. When mated with the delivery wire and pusher catheter described below, they can serve to control micrograft linear movement relative to the wire.
• a radiopaque agent as described above could be utilized which would allow complete visualization of the full length of the graft.
• Another way to provide visualization is the inclusion of a radiopaque coil or insert across the entire length of the inner lumen of the micro-graft. The addition of such coil would make the entire length of the graft radiopaque, however, preferably, to avoid such coil adding an unwanted increase to the structure’s radial stiffness, and to minimize such stiffness while maximizing x-ray visibility, such coil may be wound using very thin wire typically not visible via fluoroscopy, but when coiled with sufficiently small pitch (spacing between each loop) it becomes increasingly dense and visible.
• the coil may also vary to make some sections more radiopaque or flexible than others.
• the coil can be made of materials such as platinum, platinum-iridium, tantalum, gold, silver or other radiopaque materials used for medical device visualization.
• the coil can have a continuous diameter or variable diameter along its length, depending on use.
• the coil can also be used in combination with radiopaque bands, coatings or as a stand alone radiopaque solution. Insertion of such coils inside the micrograft may also reduce the amplitude of macrocrimps formed during crimping if desired, depending on radial apposition of coil to braid.
• coils or other internal inserts may be partially visible through the braid wall depending on the amount of crimping, although in a preferred embodiment, the braid is closed cell, defined herein as the inner coil not being visible between braid strands or not being directly visible through gaps of the braid. However, in a preferred embodiment, the closed cell configuration still has sufficient spaces between the yams and filaments for blood flow as discussed herein.
• a simple“J” shape can be heat set into tubular body 12 to aid with introduction into the aneurysm.
• Agents may also be added to the tube to aid in delivery and/or endothelial cell growth.
• a hydrophilic coating can be applied to the surface of tubular body 12 to aid in delivery through a microcatheter or a swellable hydrogel infused with drugs can be added to provide medicinal treatment and additional filling of the aneurysm.
• a clotting agent which may be added to either slow or inhibit the clotting process or to promote clot formation.
• Bio-absorbable and bio-compatible fibrous elements such as Dacron (polyethylene terephthalate), polyglycolic acid, polylactic acid, a fluoropolymer (polytetrafluoroethylene), nylon (polyamide) or silk can also be incorporated into the braid, or to the surface, to enhance the ability of the tubular body 12 to fill space within the vasculature and to facilitate clot formation and tissue growth.
• hydrogels, drugs, chemotherapy beads and/or fibers can be added to the inner diameter of tubular body 12 or infused into the walls, yams, or fibers depending on specific use (for example embolic chemotherapy).
• a microcoil On the finishing side of the micrograft (proximal end), a microcoil (not shown) may be added to provide a barrier between the aneurysm sac and the parent vessel.
• Figure 1 can include similar features or functions as will be described below.
• Figures 2 A- 2C illustrate a micrograft similar to micrograft 10 of Figure 1 except having a larger diameter and thinner wall.
• Figure 2A illustrates the thin walled micrograft 25 crimped in the process described above to forms peaks and valleys resulting in circumferential corrugations or folds.
• Figure 2B is provided for illustrative purposes to highlight the peaks and valleys by stretching the tubular body.
• Figure 2C shows a portion of the micrograft 25 in the bent position.
• the micrograft is pre-set in this bend, e.g., a U-shaped configuration, to improve packing within the aneurysmal sac. As shown, due to the structure of the micrograft, when bent, it maintains its radius in the similar manner to a bent coil.
• micrograft would be delivered in a substantially linear position as described below.
• the compression and heat setting (crimping) process creates an“accordion like” structure with peaks 18’ and valleys 20’.
• the wall of the micrograft 25 is a fine braid, or textile structure, and will approximate a solid structure when placed in direct blood flow, causing high flow disruption.
• Another feature of the graft is its white color, which may vary depending on PET formulation and processing. If desired, colors other than white may be used to denote different body diameters or transitions in mechanical or therapeutic properties, for example.
• crimping alters the direction/orientation of the yams/filaments with respect to a longitudinal axis of the tubular braid.
• the yams/filaments after crimping, are substantially transverse to the longitudinal axis.
• the yams/filaments after crimping are at about 35 degrees to the longitudinal axis, or between about 35 degrees and about 90 degrees.
• the yams/filaments after crimping are at about 45 degrees to the longitudinal axis, or between about 45 degrees and about 90 degrees.
• the effect of crimping is to increase the angle of the yam or filament relative to the longitudinal axis, i.e., if the uncrimped braid angle is X degrees with respect to the longitudinal axis, the braided angle when crimped is X + Y degrees.
• Y In preferred embodiments, Y>5 degrees, although other values of Y are also contemplated.
• braid angle relative to longitudinal axis (typically referred to as the alpha (a) angle) is measured while braided structure is in a straight orientation, however, the angle may also be measured between crossing yams or filaments (typically referred to as beta (b) angle) in which case the value would be double (2X degrees) as exemplified in Figure 25B discussed below (compare angles B and C).
• tubes braided with 16 ends (yams) and braid angles above 40 degrees (relative to longitudinal axis) become increasingly challenging to process, are much stiffer, and increased friction between the tight braid and mandrel hinders removal of the mandrel from inside the braid.
• such braids are typically manufactured with braid angles below 40 degrees.
• the typical maximum a braid angle is even lower, around 30 degrees. Crimping, therefore, as disclosed herein, as a secondary process, allows increase of PPI and braid angle while maintaining softness/conformability/ flexibility.
• Crimping increases the amount of thrombogenic (fiber) surface exposed to the body. That is, crimping increases the amount of fiber material per unit length as the length of the braid decreases and the diameter increases. In some embodiments by way of example, the length of the tubular body can decrease as a result of crimping by about 50%, although other decreases in length are also contemplated.
• FIGS 4A, 4B, 4D and 4E-4M show an alternative and preferred embodiment of the micrograft, designated generally by reference numeral 10’.
• Micrograft 10’ is similar to micrograft 10 as it formed from a braided tube 12’ and has the same features and functions of tube 12 as well as can include any of the alternate braid constructions described herein.
• the various descriptions herein of the filaments, yams, capillary effects, shape set, etc. are fully applicable to the micrograft 10’ of Figure 4A.
• micrograft 10’ has a core element 27, preferably formed by a helical coil, having a lumen for blood flow in the aforementioned capillary effect.
• the coil is formed into a helical shape and has a proximal end 27a ( Figure 4F) and a distal end 27b. Lumen 27c extends through the coil 27 from the proximal end 27a to the distal end 27b.
• the coil 27 is composed of a metal such as platinum or a platinum tungsten alloy.
• the textile structure in the form a tubular braid 12’ is positioned over the coil 27. That is, the braid is formed separately into a tubular shape with a lumen or longitudinally extending opening 39 extending from the proximal end to the distal end for receipt of the coil 27.
• the braid 12’ is preferably composed of PET or other thrombogenic material.
• the braid 12’ can be in the forms disclosed herein and is preferably substantially a closed cell design to provide a large percentage of outer surface area for contact with the blood and/or vessel/aneurysm wall. However, although generally a closed cell design, it has spaces between the yams and filaments as described herein to enable blood flow into and/or through the device. Such flow achieves the capillary effects described herein. This configuration promotes tissue ingrowth in a relatively short amount of time, and in some instances within 30 days of implantation.
• the micrograft 10’, with braid 12’ and attached inner coil 27, is formed into a helical coil shape as shown in Figure 4K with a lumen 39 extending along its length.
• the braid is preferably crimped to increase the braid angle and increase softness, compressibility and amount of thrombogenic surface area in the device.
• the structural effect of such crimping can be appreciated by the comparative views of Figures 25A-28B.
• Figures 25A and 26a show the braid 12’ before crimping wherein the braid 12’ has an angle A with respect to the longitudinal axis L of the tubular braided textile structure 12’.
• Figures 25B and 26B illustrate the braid 12’after crimping where the braid 12’ has an angle B with respect to the longitudinal axis L of the tubular braided textile structure 12’which is greater than angle A.
• Angle C of Figure 25C depicts the alternate way to measure braid angle by measurement between crossing filaments.
• This configuration of the embodiment of Figure 4A also encourages rapid blood clotting and in some instances clotting can occur immediately upon implantation.
• the micrograft (implant) 10’ when the micrograft (implant) 10’ is held in the delivery system within the vessel/aneurysm but prior to release from the delivery system, the micrograft 10’ becomes filled partially or entirely with blood so that blood stagnation can commence even before the micrograft 10’ is released and implanted, thereby expediting thrombus formation. Saturation of the micrograft in the delivery assembly and once implanted accelerates and/or improves thrombosis.
• braid fibers are not only thrombogenic (attract blood platelets and proteins which promote clot) due to their material, e.g., PET can be used as the filaments or as a thrombogenic surface, but also promote stasis as the braid structure traps blood.
• the braid is melted onto tube 29, with region 24a showing the melted fibers, to attach the tube 29.
• the tube 29 (or tubes 29’, 29”, 29’”) extends proximally of the core element 27. It also extends proximally of the tubular textile structure 12’ so a proximal region is exposed for engagement by a delivery member. A distal portion of the tube 29 is within the tubular textile structure.
• threads in the tube 29 for attachment to the core element windings allows the textile structure, e.g., braid, to melt into the threads, thereby further stabilizing/reinforcing the attachment of the outer textile structure 12 to the inner elements. That is, the cut feature in the tube 29 provides a better joint (increased bond strength) between the textile structure 12’ and the tube 29’ as the melted material (textile structure) flows into the spaces between the threads. It is contemplated that instead of threads, laser cut holes or tabs or other engagement features can be provided to attach the tube to the inner (core) element by screwing into, pressing into or other methods of interlocking.
• these engagement features e.g., cut features or surface gaps
• these engagement features can be used instead of threads for twisting into or other attachment of the tube to the proximal coils of the core (inner) element and such features can also be provided to receive the melted material (textile structure).
• other laser cut features such as holes or surface gaps can be made in the tube to provide additional spaces for the melted material to increase the strength of the attachment. These additional spaces can be in addition to the features for attaching the tube to the inner element.
• tube 29 has a deflectable tab 29a and a window 29b to receive a delivery wire as described below in conjunction with the delivery method.
• Region 24b ( Figure 4F) illustrates the region at the proximal end where the fibers of braid 12’ are melted onto the proximal end of coil 27.
• Figure 4F an alternative tube configuration is illustrated, with tube 29’ having a slot to receive a ball or hook as in Figure 22 A.
• electrolytic detachment of the implant is disclosed with wire 230 held within tube 29’ by epoxy 232 or other material to which it is attached, e.g., glued or fused.
• the material 232 provides an insulator to ensure the wire 230 is not in contact with the tube 29’.
• the micrografts of Figures 4F-4H are identical to micrograft 10’ of Figure 4A.
• Tube 29’ can be screwed into the coils of core element 27 in the same manner as tube 29. It should be appreciated that tubes 29, 29’ (and electrolytic detachment) can be used with the braid of Figures 4A-4M as well as with any of the other micrograft and braid embodiments disclosed herein.
• braid (braided tube) 12’ is made up of yams 31 each containing multiple fibers 33.
• the yam(s) 31 of tube 12’ will lay relatively flat with the fibers 33 bundled horizontal and spaced apart (see Figure 4D showing tube 12’ positioned over mandrel 35).
• Figure 4E illustrates the braided tube 12’ which has been crimped over mandrel 35 to create crimped braided tube 12’ prior to formation into the structure of Figure 4A. This is also described below in conjunction with the method of manufacture.
• the inner diameter of the tubular braid 12’ is preferably about .003” to about .012”, and more preferably about .007”.
• the coil 27 can have an inner dimeter of about .002” to about 010”. In some embodiments, the coil can have an inner diameter between about 001” to about .002” less than the inner diameter of the braid. In other embodiments, the coil can have an inner diameter greater than the inner diameter of the tubular braid since the braid expands in diameter upon crimping.
• Figures 4N, 40 and 4Q illustrate alternate embodiments of the device having an optimized joint between the outer polymeric structure and inner element.
• a balance needs to be achieved in the overall device between the stiffness of the device to maintain its heat set shape and the softness/flexibility of the device to avoid damage to the vasculature and to enhance aneurysm packing.
• the components of the device i.e., the outer polymeric structure, e.g., a textile structure such as the aforedescribed braid
• the inner element e.g., a radiopaque coil such as the aforedescribed metal coil
• connection i.e., joint
• the connection is of insufficient length, it will be too weak and the polymeric structure and inner element could separate during delivery through tortuous vasculature and/or in use/placement within the aneurysm.
• the connection i.e., joint
• the connection is too long and thereby too stiff, it could be hard to deliver and in some instances possibly undeliverable through tight turns in tortuous vessels and could also increase the risk of rupturing the aneurysm.
• the joint has a solid (non-porous) outer surface, it prevents tissue ingrowth. Therefore, the longer the attachment (connection), the less surface area of the implant available for tissue ingrowth. Stated another way, the advantages of a shorter joint are that it reduces the stiffness of the device and maximizes the area for tissue ingrowth. However, the joint must be long enough to maintain attachment of the components/materials.
• the implant 300 is identical to implant 10’ of Figure 4F except for the joint.
• the term joint denotes the connection or attachment of the outer polymeric structure, i.e., the braid, to an internal (inner) component, i.e., the radiopaque coil and/or metal tube, within the braid.
• the joint can be an attachment formed by application of energy to bond the materials/components, formed by an adhesive attachment, formed by a mechanical bond, or formed by other methods. Examples of use of energy include heat (for melting), ultrasound, laser and electric current.
• the biocompatible polymeric structure can be a textile structure formed by manufacturing processes such as weaving, knitting, and braiding or may be a porous structure made by electrospinning or extrusion.
• the polymeric structure is porous, i.e., has spaces to maintain porosity which can let air or gas through and in preferred embodiments sufficiently spaced to let in blood.
• the polymeric structure is a textile structure in the form of a braid composed of a plurality of filaments and a plurality of yams as discussed herein.
• the inner element is in the form of a coil, preferably radiopaque, and can be made of a polymer or metal.
• region 324 denotes the distal joint formed by melting the fibers of the textile structure, i.e., the braid, onto the inner coil, i.e., the radiopaque metal coil.
• the distal joint 324 extends for a length LI between about .002 inches and about .050 inches. In a more particular embodiment, the distal joint 324 extends for a length of between about .004 inches and .020 inches. Note that other lengths are also contemplated, however, the foregoing ranges optimize the joint length by obtaining the minimum length for secure attachment without unduly sacrificing flexibility or sufficient tissue ingrowth.
• the distal joint 324 covers at least two windings (also referred to as wire loops or rings) of the inner element 327, shown in Figure 4N as a metal coil similar to metal coil 27 described herein. It has been found in some embodiments that covering, e.g., attachment, to two coil windings achieves the desired balance/objectives described above.
• the inner metal coil 327 extends to the distal end of the textile structure 12 which is in the form of a braid in Figure 4N.
• distal joint 324 covers two coil windings 327a, 327b, which are the distalmost windings of coil 327.
• radiopaque coil 328 can be positioned within the distal coils of metal coil 327 to provide a closed pitch and also enhance radiopacity for imaging of the distal portion of the implant 300.
• An optimal melt joint will fuse at least two coil windings of a single coil or at least one coil winding from each coil when two coils or helical elements are being joined together.
• implant 400 has an inner coil 427, which is a metal coil similar to coil 27, that extends a further distal distance beyond the distal edge of the textile structure 12 (which is in the form of a braid).
• the distal joint 424 extends from the distalmost part of the textile structure 12 to cover two coil windings 427a and 427b, which are spaced proximally from the distalmost coil winding 427c of the inner element 427.
• a small weld joint 427d at the distalmost end joins the coils together.
• the distal joint 424 extends from the braid to a portion of the inner element 427 spaced proximally from its distalmost end.
• the distal joint 424 like distal joint 324 of implant 300 of Figure 4N, extends for a length L3 between about .002 inches and about .050 inches, and in a more particular embodiment for a length from about .004 to about .020 inches. Note that other lengths are also contemplated, however, the foregoing ranges optimize the joint length by obtaining the minimum length for secure attachment without unduly sacrificing flexibility or sufficient tissue ingrowth.
• Figure 40 also differs from Figure 4N at the proximal joint which is discussed in detail below. In all other respects, the embodiment of Figure 40 is the same as the embodiment of Figure 4N.
• Note implant 400 can also include an additional radiopaque coil 428 positioned within the distal coils of metal coil 427 which provides a closed pitch and also enhances radiopacity for imaging of the distal portion of the implant 400.
• the exposed length of the radiopaque coil distal of the distal joint 424 can be closed pitch as shown.
• region 330 denotes the proximal joint formed by melting the fibers of the textile structure, i.e., the braid, onto the metal tube 329 which is the same as metal tube 29 of Figure 4A.
• Tube 329 can be screwed into the proximal coils of inner element 327 in the same manner as discussed above with respect to tube 29 or attached by other methods.
• region 370 denotes the proximal joint formed by melting the fibers of the textile structure onto the metal tube 379 (which is the same as tube 329) and at least one coil winding of inner coil element 377.
• the vascular implant of Figure 4Q is the same as the vascular implant 300 of Figure 4N.
• the proximal joint 330 (and 370 of Figure 4Q) extends for a length L2 between about .002 inches and about .050 inches.
• the proximal joint 329 extends for a length of between about .004 inches and .020 inches. Note that other lengths are also contemplated, however, the foregoing ranges optimize the joint length by obtaining the minimum length for secure attachment of the braid 12 and tube 329 (or tube 379 and inner element) without unduly sacrificing flexibility or sufficient tissue ingrowth.
• the proximal joint can be formed by the various methods described herein, e.g., energy application, adhesive, mechanical bonding, etc.
• the distal joint is formed by heating the braid to form a melt joint with the inner metal coil 327, 427, 377, respectively.
• the proximal joint 330 is formed by heating the braid to form a melt joint with the metal tube; in the embodiment of Figure 4Q, the proximal joint is formed by heating the braid to form a melt joint with the metal tube and the inner coil; and in the embodiment of Figure 40, the proximal joint 430 is formed by heating the braid to form a melt joint with a proximal region of inner metal coil 427, e.g., the two proximalmost coil windings of inner coil 427, since the metal tube is not provided.
• the proximal joint 430 preferably has a length L4 as described above with respect to length L2 of Figure 4N. Note that the distal joint of Figures 4N, 40 and 4Q can be utilized with the proximal joint of Figures 4N or 40 depending on whether a metal tube or other helical element is provided at the proximal end of the inner metal coil.
• melt joint preferably covers a width of the yam of the braid.
• the joint 324, 424, 330, 370 and/or 430 can be formed other than by heating such as by vibrational methods, adhesive, etc.
• the distal joint 324, 424, respectively is continuous along a length.
• proximal joints 330, 430 370, respectively are continuous along their length.
• the distal and/or proximal joint of these embodiments be non-continuous. This is illustrated for example in the embodiment of Figure 4P wherein the distal joint 524 is formed by a plurality of discrete spaced apart (non-continuous) sections. As shown, joint 524 is composed of discrete melted (or alternatively welded or adhesive) areas along a length L5 of between about .002 inches and about .050 inches.
• the distal joint 524 extends along a length of between about .004 inches and .020 inches. Stated another way, the distance from the proximalmost attachment of the textile structure 12 and inner coil 527 to the distalmost attachment of the textile structure 12 and inner coil 527 is preferably within these ranges. Note that other lengths are also contemplated, however, as noted above, the foregoing ranges optimize the joint length by obtaining the minimum length for secure attachment without unduly sacrificing flexibility or sufficient tissue ingrowth. Note the proximal joint 530 (attaching the braid 12 to the proximal coil windings or alternatively to a metal tube like tube 29) can also be non-continuous like the distal joint 524.
• attachments A1 and A2 e.g., melts or welds
• additional attachments e.g. melts or welds
• Other spaced ways of attaching e.g., adhesive, are also contemplated.
• a mechanical joint can be utilized instead of a heat or adhesive joint. That is, a band, preferably composed of metal, can be swaged or otherwise mechanically attached to the braid.
• the length of the band is preferably between about .002 inches and about .050 inches to achieve the advantages enumerated above associated with these lengths.
• the metal band extends for a length of between about .004 inches and .020 inches. Note that other lengths are also contemplated, however, the foregoing ranges optimize the band length by obtaining the minimum length for secure attachment without unduly sacrificing flexibility or sufficient tissue ingrowth due to the non-porous outer wall of the band.
• the metal band can have a continuous outer wall of the foregoing lengths or non-continuous outer wall (e.g., axially spaced bands) of the foregoing lengths to satisfy the above balance of competing factors regarding its length.
• a band can be provided to form a mechanical distal joint at a distal end of the implant and/or a mechanical proximal joint at a proximal end of the implant.
• proximal and distal joints can be utilized with the other embodiments of implants disclosed herein.
• the implant 350 includes two polymeric structures 352, 354 attached at a proximal end.
• the two polymeric structures can be any of the polymeric structures, such as the braided structure, with an inner element, e.g., a radiopaque coil such as a metal coil, positioned herein.
• the polymeric structures can have the distal and/or proximal joints discussed above to avoid undue stiffness.
• the polymeric structures 352, 354 are shown attached at their proximal ends to a radiopaque element, e.g., a coil or marker band 356 and are unattached at their distal ends.
• a radiopaque element e.g., a coil or distal marker band 357, 358, can be provided at their distal ends.
• the polymeric structures 352, 354 are joined at their distal ends by a radiopaque element such as a coil or marker band.
• the polymeric structures 352, 354 can be joined by a radiopaque element at their proximal end and/or their distal end.
• the side-by side double braid configuration provides a more efficient packing of the aneurysm. It can also save procedural time by enabling insertion of two braids simultaneously. Note that any of the implants disclosed herein can be provided as a double structure as in Figure 29 to obtain these advantages.
• a marker band 22’ is attached to the tube to provide retention structure for engaging structure on the delivery wire.
• the micrograft of Figure 4C is the same as the micrograft 10’ of Figure 4 A and has therefore been labeled with the same reference numerals.
• the braid of the implant is preferably non-expandable. That is, after formed, a dimension measured through a transverse cross-section of the implant (braid and coil) is the same in a delivery position within a delivery member as in the placement position.
• the implant may be stretched to a reduced profile position for delivery and then released for placement to assume its coil shape discussed above. However, when it moves from the delivery to the placement position, the braid does not expand. The change is to the implant (braid and coil) from the linear shape within the delivery member to its secondary helical shape within the body, but the combined thickness of the braid and coil (i.e., the outer diameter of the braid) remains constant during delivery and placement.
• the braid is formed separately into a tubular form and then the coil is positioned within the braid before heating and melting of the braid onto the coil.
• the braid is not wound onto the coil but is formed separately and the two elements/components (structures) subsequently attached.
• the braid (formed by the aforedescribed filaments) is formed on a mandrel.
• the braid in a preferred embodiment is composed of PET, although as noted above, other materials are contemplated.
• the textile structure can alternatively be in the form of a woven textile structure, an electrospun structure formed from one or more polymeric fibers, or other overlapping fiber arrangements/structures formed into a tubular shape as in step 2 below).
• the tubular braid is compressed on the mandrel to crimp the braid, increasing the amount of fiber per unit length and/or in certain embodiments forming peaks and valleys as described above. Note when the tubular braid is compressed, the inner coil is not within the braid, so that the crimping does not affect the coil.
• the braid is removed from the mandrel to ready for attachment to the inner element, i.e., the metallic coil.
• the metallic coil is formed by winding a wire about a mandrel into a helical shape, and the opposite ends of the coil wire are attached, e.g., glued, in tension around the mandrel.
• the tensioned metallic coil is positioned within the tubular braid, i.e., inserted into the tubular braid or the tubular braid is slid over the tensioned metallic coil, which in either case means the metallic coil is“insertable into” the braid. Note in this tensioned position, the metallic coil is tightly wound around the mandrel and of a reduced height (the height defined as the diameter or transverse dimension measured from a topmost point along the length to a bottommost point along the length of the coil).
• the coil wire in a preferred embodiment is composed of platinum alloy for radiopacity, although other radiopaque materials can also be utilized.
• the coil wire 27 comes into contact with some or all of the inner surface of the valleys and not in contact with the peaks.
• An example of this is shown in the cross- sectional view of Figure 4G wherein coil 27 contacts the inward portions of the braid 12’.
• One end of the tubular braid is heated to melt onto the coil to attach the tubular braid and coil (at a melt joint) to form the braid/wire assembly (implant).
• the mandrel can be left during melting or alternatively removed prior to melting.
• a filament (yam or wire) is threaded through the device lumen (so the device is able to slide over the filament) to aid in formation of a second device configuration.
• each successive heat treatment is at a higher temperature and/or a longer duration to improve shape retention of that treatment and to control shrinkage of the braid.
• the final heat treatment can be used to impart the most shrinkage of the braid to aid in setting the secondary shape.
• the secondary shape is a helical shaped, although, alternatively, the secondary shape could be other 3D shapes, such as spherical, conical, etc. 1 l)The device (atached braid and coil) is removed from the oven to cool and the filament and shaping mandrel/fixture removed, leaving the assembly (implant) in its set secondary shape.
• a nitinol tube such as tube 29 as discussed above (or alternatively a stainless steel tube) is inserted into the coil at one end of the tubular braid.
• the tube has a helical feature cut into one end.
• the tube in some embodiments is attached by rotating or screwing it in between the windings of the coil wire so the helical feature interlocks with the windings.
• Nitinol provides resiliency which reduces the likelihood to break when acting as a lock component with the pusher of the delivery system. Also Nitinol provides more favorable MRI visualization (less interference).
• the tube is preferably made of Nitinol, alternatively other materials such as stainless steel can be utilized.
• the inner diameter and outer diameter of the tube is the same or substantially the same as the inner diameter and outer diameter of the coil wire so that the tube and coil wire are substantially flush.
• the coil and tube can have a stepped surface.
• the braid is heated to melt onto the nitinol tube and the end of the coil, thereby ataching the tube to the braid and coil, forming the final assembly (micrograft/implant).
• the melted braid region covers the entire region where the helical feature (thread) of the tube and coils of the metallic coil are intertwined. The material flowing into the helical structure reinforces the joint.
• Crimping makes the tubular braid softer as there is more room for the tubular braid wall to compress.
• the increased compressibility enables a higher packing density in the aneurysm, i.e., more implants can be fited in the aneurysm, and fill a higher volume.
• the increase in the amount of thrombogenic fiber per unit length of the device is also directly proportional to the amount of crimping (compression) and as stated earlier, depending on the braid filament type or patern, does not always result in peaks and valleys. It does, however, reduce braid cell size while increasing braid angle and outer diameter.
• the sufficiently crimped braids (high braid angle) disclosed herein made with multifilament yams maintain a closed cell structure on the outer bend surface even if deflected or coiled in a secondary shape. That is, although the tubular braid in its coiled secondary shape will experience compression of the yams/filaments on the inside of its bend radius and stretching/expansion of crimped yams on the outside of the bend radius, it still does not allow visibility of the internal coil through the braid surface. In other words, the crimped braid will maintain its closed cell configuration in the linear as well as in a non-linear, e.g., bent or curved or coiled, configuration. In contrast, for uncrimped and monofilament tubular braids, the inside bend surface will experience compression and a reduction in cell size and porosity whereas the outer bend surface will experience cell/pore size increase (resulting in open cell structure).
• the implant is formed into a secondary shape after insertion of a filament through the device lumen.
• the inner coil is released from a tensioned positioned once inside the tubular braid to move to its less tensioned more relaxed position. In this position, in some embodiments, portions of the coil may remain out of contact with the braid.
• the braid By crimping the braid without the internal coil, avoidance of compression of the coil is achieved, which due to different heat set temperatures of the braid and coil materials, could result in the coil not being shape set to a shorter length and remaining in tension relative to the braid. Also, since crimping increases the inner diameter of the braid, the inner diameter of the braid can be set and then a coil positioned therein, which in some instances can have an outer diameter larger than the internal diameter of the uncrimped braid. This enables a larger coil to be used. Note in an alternate method, the braid is compressed with a coiled wire positioned inside, but the coiled wire is a closed pitch coil so it is not compressible.
• the closed pitch coil is mechanically clamped to a mandrel, so that when the braid is crimped, the coil cannot change in length so therefore would not be under tension.
• compression of the braid is achieved without compression and tensioning of the inner coil wire.
• the former method utilizes an open pitch coil which facilitates healing.
• the braided tubular structure is formed directly over the metallic member whereby releasing the metallic member causes it to expand within the braid.
• Figure 3 A illustrates another embodiment of an intra-aneurysmal micrograft.
• a variable stiffness micrograft 26 with tubular body 28 includes the same features and functions as described above with respect to Figure 1, or its alternatives, e.g., multifilament yams, capillary effects, etc.
• the micrograft 26, after forming and crimping is wound about a mandrel to form a secondary coil shape as shown.
• Figure 16B wherein the micrograft 26 is pictured both after braiding and crimping (still straight) and after it is wound into a coil after formation of such braided and crimped structure.
• Such helical configuration is also shown in Figure 4K where a secondary configuration of the micrograft 10’ of Figure 4A is formed.
• Other micrografts described herein, with the varying features described herein, can also be wound into a coil shape of Figure 3 A if desired.
• the tubular body 28 of micrograft 26 is composed of a variable stiffness braid having a proximal stiff section 30 and a distal flexible section 32, the varying stiffness achieved in the ways described above.
• Tubular body 28 also has a primary diameter D.
• a radiopaque band 36 can be provided to allow visualization under fluoroscopy and is shown in the approximate center of the braid where it transitions in stiffness.
• the radiopaque band 36 can alternatively be positioned in other locations and multiple bands can be provided. Alternatively, radiopacity can be achieved in the various ways described above.
• Device 26 is shape-set with heat in a pre-biased (secondary) helical shape of Figure 3 A (and 16B). This is the delivered shape-set form of the device 26. This device may not have such pronounced peaks and valleys as micrograft 10 due to the stretching, bending and heating needed to form secondary shapes. However, the original crimping operation induces the desired properties and makes the micrograft more compliant. Partial stretching or partial un-doing of the crimping also results in a braided lumen that is more compliant radially for improved packing.
• device 26 can be shape set into any complex three dimensional configuration including, but not limited to, a cloverleaf, a figure-8, a flower-shape, a vortex-shape, an ovoid, randomly shaped, or substantially spherical shape.
• a soft, open pitch coil can be added to the inner diameter of the braid to aid in visualization. If stiffness of such metal coil is sufficiently low, the secondary shape-set of the polymer braid will drive the overall shape of the device. In other words, the secondary shape of the braid molds the unshaped metal coil which normally shape sets at temperatures much greater than the glass transition temperature of polymers.
• the micrograft 26 also has frayed end fibers 38 shown on one end of the device. These loose frayed fibers can alternatively be on both ends of the braid, if desired (other micrografts disclosed herein could also have such frayed ends). When these frayed ends come in contact with another braid within the aneurysm sac having the same feature, the mating ends act like Velcro, allowing the micrografts to interlock and move together.
• device 26 For delivery and introduction into catheter, device 26 would be elongated, e.g., moved to a substantially linear configuration, and inserted into a loading tube having an inner diameter of sufficient size to accommodate primary diameter D.
• An optional filament may extend from the proximal end of the braid to allow pinching/anchoring of the micrograft between a stent or flow diverter and the parent vessel wall upon release to obstruct flow at the aneurysm neck. Packaging and delivery is discussed in detail below.
• FIG. 3B illustrates another embodiment of an intra-aneurysmal micrograft.
• Sliced micrograft 40 has a tubular body 42 that can include the same features and functions as described above for the previous embodiments, e.g., multifilament yams, capillary effects, etc.
• Tubular body 42 has a longitudinal cut 44 and is shape set to expose its inner surface 46, thereby providing a flared distal end.
• Micrograft 40 is configured with a portion of the inner diameter exposed to maximize surface area constricted by flowing blood and to aid in movement with blood flow.
• Device 40 can include a proximal marker band 48 (or alternatively any of the other aforedescribed radiopaque features) for visualization.
• Micrograft 40 is particularly suited for placement at the neck of the aneurysm either manually with a delivery system or through movement with blood flow circulating within the aneurysm. Delivering micrografts 46 to an aneurysm may result in clogging at the neck/stent interface as they get caught up in exiting blood flow and accumulate at the aneurysm neck.
• This structure can also be a round tube, flattened tube, or other shape that is easily moved by blood flow.
• tubular bodies for the above embodiments have been described as crimped braided tubes, however, the tubes can be made using other manufacturing methods such as weaving, knitting, extruding, or electro-spinning. Structures can also be manufactured with alternating diameters or cross-sections, such as flat to round.
• the tube can be made from a rolled sheet or other material formed into desired tubular or substantially cylindrical structures. Structural flexibility can then be adjusted either by crimping or selective laser cutting, for example. If desired, the tubular body can also be flattened to create a thin walled tape or heat pressed to create oval sections.
• crimping or the use of axial/longitudinal compression and heat is described to produce crimps or peaks and valleys
• other manufacturing methods of constructing peaks and valleys can be utilized to achieve similar effects.
• a wire may be wound tightly around a braid placed on a mandrel. The gaps between windings will create peaks and when the assembly is heat set (with or without longitudinal compression) and the wire removed, valleys will be formed where the wire compressed the braid and peaks where the braid was exposed.
• Figures 16A through 16C and Figure 17 illustrate a portion of micrograft 10 tubular body 12 constructed of 20 denier/18 filament polyester yam.
• Figure 16A shows examples of an uncrimped tubular body 171 alongside a crimped micrograft 10 tubular body 12 to illustrate the formed macro peaks and valleys.
• Figure 16B shows a crimped tubular body alongside a tubular body that has been shape set into a helical coil 172 post crimping similar to Figure 3 A.
• Figure 16C shows micrograft 10 that has fluid 174 which has been drawn into the micrograft via capillary action described earlier.
• Figure 17 shows a tubular body with a marker band (stop collar) 22 attached to the body as in Figure 1.
• FIGS 30-33 illustrate an alternate embodiments of the implant wherein the tubular member, i.e., tubular textile structure, described herein forms an inner member or inner structure of the implant and is positioned within an outer member or outer structure.
• the outer member forms a lattice structure forming a scaffold for tissue ingrowth and the inner member is an absorbent structure encouraging blood flow therein and promoting tissue ingrowth as in the textile structures described herein.
• the textile structure becomes soaked with blood and traps blood therein causing relatively rapid stagnation of blood.
• any of the textile structures described herein can form the“inner member” of the embodiments of Figures 30-33, and can be encapsulated in whole or in part by the “outer member.”
• the inner member can include one or more radiopaque elements for imaging as in the tubular textile structures disclosed herein.
• the inner member can be crimped as described above.
• the inner tubular member e.g. textile structure 602 is positioned within an expandable outer structure (outer member) 604 of implant 600.
• the outer structure 604 moves from a non-expanded or less expanded delivery position, also referred to herein as a reduced profile position, to an expanded placement position when exposed from the delivery member.
• the tubular member 602 can be the structure of the braided tube 12 or 12’ described herein, or any of the alternate structures also described herein, and is preferably an absorbent textile structure made of a plurality of yams formed from a plurality of filaments, and the filaments of the yams have spaces therebetween to induce flow of blood between the filaments of the yam to transport blood along the yams.
• the yams are formed into a permeable structure to allow inflow of blood between the yams and through the tubular member 602 so the tubular member 602 becomes saturated with blood to cause stagnation of blood and blood clotting.
• Tubular member 602 has a proximal opening 608 and a distal opening 606 so blood can flow through the distal opening 606, through the lumen of the tubular member, and out the proximal opening 608. It is also contemplated that the proximal end can be closed so blood flowing through the distal opening 606 and through the lumen does not exit through a proximal end.
• Tubular member 602 can include an internal member in the form of a radiopaque coil, which can be identical to the coil (core element) described herein, e.g., coil 27 of Figure 4A. It can also have a tubular member attached thereto. Alternatively, or in addition, the tubular member 602 can include one or more marker elements (structure) or bands at its proximal region, its intermediate region and/or its distal region.
• the outer member 604 can also include radiopaque marker element(s) at proximal, distal, and/or intermediate portions. In the embodiment of Figure 30, by way of example, distal and proximal marker bands 607, 609 are shown at the respective distal and proximal ends of the outer tubular member 604.
• the outer structure of Figure 30, as well as the outer structures of Figures 31-33 described below, can be in the form of a braid or mesh composed of a metallic material such as cobalt chromium, a nickel titanium alloy (Nitinol), the combination of these materials or composed of other materials.
• the inner tubular member 602 promotes tissue ingrowth. Blood enters between the spaces in the outer member 604.
• the inner tubular member 602 extends linearly within the outer member 604 during delivery.
• the inner tubular member 602 preferably does not expand beyond its primary outer diameter (or beyond the inner diameter of the delivery catheter).
• the outer member 604 during delivery in some embodiments can collapse onto the inner member 602 and squeeze it down while inside the catheter. When the implant 600 exits the delivery catheter, the outer member 604 would then expand beyond the internal diameter of the catheter and the inner member 602 would just expand back to its primary inner diameter (which is less than the catheter inner diameter).
• the inner member can be sufficiently thin so it would not be compressed by the outer member such that its outer diameter remains unchanged from its delivery position to its placement position within the aneurysm.
• the inner member 602 forms a non-linear, e.g., 3D helical, shape when implanted (positioned) within the aneurysm.
• the outer member 604 as noted above is preferably expandable.
• the outer member 604 illustratively fully encapsulates the inner member 602 but in alternate embodiments only partially encapsulates the inner member 602.
• Inner member 602 may also be attached to outer member 604 at distal and/or proximal ends.
• the implant 600 can be placed at the neck of the aneurysm, extending into the aneurysm, to contact the wall of the neck and the wall of the aneurysm. It is also contemplated, that the implant can be placed fully within the aneurysm spaced from the aneurysm neck.
• the inner tubular member (inner textile structure) 622 is positioned within outer member (structure) 624 of implant 620.
• the inner tubular member 622 is similar to inner member 602 (which can be the structure of the braided tube 12 or 12’ described herein, or any of the alternate structures also described herein), and is shown in a helical shape in the placement position.
• the inner member 622 could be compressed by the outer member 624 during delivery and preferably does not expand beyond the inner diameter of the delivery catheter when the implant 620 is released from the catheter. If sufficiently thin, it would not be compressed during delivery so its transverse dimension would not increase as the implant moves from the delivery to the placement position.
• the outer member 624 is bulbous shaped, e.g., spherical in shape, and is expandable from a reduced profile delivery position to a placement position to fill the space within the aneurysm.
• the outer member 624 is formed from a braid, a mesh or other structure which has sufficient gaps for blood to flow into the inner member 622 and for tissue ingrowth into the inner member 622.
• the outer member 622 can be composed of materials listed above for structre 604.
• the inner member 622 is fully contained within the spherical outer member 624, tu in alternate embodiments can be partially contained.
• Distal, proximal and/or intermediate radiopaque marker elements can be provided on the inner member 622 and/or outer member 624.
• distal and proximal marker bands 625, 627 are provided on the outer member 624.
• the inner textile member (structure) 632 extends proximally of the spherical outer member (structure) 634 of implant 630. More specifically, portion 633 of inner member 632 is positioned within the spherical outer member 634 and proximal portion 635 of inner member 632 extends proximally of the spherical member 634.
• the spherical member 634 can be the same structure and/or material as spherical member 624 and like member 624, is expandable from a reduced profile delivery position to an expanded placement position to fill the space within the aneurysm and has sufficient gaps for blood flow into the inner member 632.
• Inner member 632 is preferably non-expandable, and can have a core (internal) element therein such as a radiopaque coil. It can also have a tubular member attached to the coil as described above.
• Distal and proximal radiopaque marker elements e.g., marker bands, 638, 639, are attached to the inner member 632 external of the outer member 634, or alternatively can be attached to the outer member 634. It should be understood that one or more of the marker elements can be placed at other regions such as on a region of the inner member 632 within the outer member 634.
• the outer member 634 could also include one or more radiopaque marker elements.
• Distal coil 637 with atraumatic distal tip 637a extends distally of the outer member 634 and can be attached to the inner member 624 and/or the marker band 639.
• FIG 31 illustrates another alternate embodiment of the implant wherein only a portion of the inner member is covered by the outer member.
• implant 640 has an inner textile tubular member (structure) 642 like inner tubular member 604 of Figure 30. That is, tubular member 642 can be the structure of the braided tube 12 or 12’ described herein, or any of the alternate structures (incluiding having a coil and tubular member attached thereto), and is preferably an absorbent textile structure made of a plurality of yams formed from a plurality of filaments for saturation and blood stagnation.
• Inner tubular member 642 like other inner tubular elements described herein, can have a core element therein such as a radiopaque coil. In preferred embodiments, the inner member 642 is non-expandable.
• Outer member 644 can be a braid, mesh, or any of the structures and materials as described herein with respect to Figure 30.
• the outer member 644 is positioned, e.g., wrapped, around one or more portions of the inner member 642 leaving one or more portions exposed.
• the distal portion 643 of outer member 644 encapsulates a distal portion of inner member 642
• an intermediate portion of outer member 644 is spaced from inner member 640 leaving a gap 646 (and a non-encapsulated (exposed) portion of inner member 642)
• a proximal portion of outer member 644 encapsulates a proximal portion 647 of inner member 642.
• different regions of the inner member 642 could be exposed, i.e., not contained within the outer member 644. That is, in alternate embodiments, different regions of the outer member would be wrapped around the inner member or varying regions of the inner member would be encapsulated within the outer member so the inner member would be partially encapsulated as parts of the inner member would be inside the outer member.
• Distal and proximal radiopaque marker elements e.g., marker bands, 649, 648, can be attached to the inner member 642 external of the outer member 644. Alternatively, one or more marker elements can be placed at other regions of the inner member.
• the outer member 634 could also include one or more radiopaque marker elements.
• FIG 34 illustrates an alternate embodiment of the implant, designated generally by reference numeral 650.
• Implant 650 has a support 652 movable from a reduced profile position for delivery to an expanded placement position within the vessel adjacent the intracranial aneurysm.
• the support can be made of metallic material forming expandable, open cell (e.g., stent like) support structure, although other materials and shapes are also contemplated.
• the support 652 can include a marker element 659 at a proximal end.
• textile structures 654a, 654b Attached at the distal end to struts 656, 657 and 658 are relatively flat textile structures 654a, 654b. More specifically, textile structure 654a is supported between struts 656 and 658 and textile structure 654b is supported between struts 657 and 658, forming an umbrella like shape for use in bifurcated aneurysms.
• the textile structures can be formed of the yams and filaments as described above, and composed of the materials described above, to provide blood stagnation, the difference being that instead of being in a tubular form they are in a flat sheet form such as a woven or knotted textile.
• the textile structure as described above can include an inner helical coil.
• the textile structure When the textile structure is stretched for delivery, its outer diameter is reduced as it lengthens so the distance from the proximal to the distal end increases.
• the inner helical coil does not stretch and reduce diameter in the same proportion, the reduction of the textile structure diameter is limited by the extent of reduction of the helical coil.
• implant 660 is configured to reduce to a smaller diameter due to the ability of the inner member to reduce to a smaller diameter than a helical coil.
• the inner member 664 is a braided structure which stretches and reduces in diameter in proportion to or closer in proportion to the outer braid 662, thereby enabling a greater reduction in the outer diameter of the outer tubular braid 662 (and the implant 660).
• the implant 660 is shown in the non-stretched (non-tensioned) or released position in Figure 36 for placement in the body, e.g., aneurysm, and in the stretched (tensioned) position in Figure 35 for delivery through a delivery sheath wherein it has a smaller outer diameter and longer length (from proximal end 668 to distal end 666). In this reduced profile position, the outer diameter is less than the outer diameter in the non- stretched position.
• the outer braid (structure) 662 can be crimped as shown to attain the benefits of crimping described above.
• the inner braid (structure) 664 can be a metal braid for example, composed of a shape memory material such as Nitinol, although other materials, including polymeric materials, are also contemplated.
• the inner braid 664 could be composed of radiopaque material or have radiopaque elements connected thereto such as radiopaque bands or tubes.
• the outer braid 662 can be the structure of the braided tube 12 or 12’ described herein, or any of the alternate structures described herein, and is preferably an absorbent textile structure made of a plurality of yams formed from a plurality of filaments for saturation and blood stagnation. In one method of manufacture, the outer braid 662 is slid over the inner braid 664 and attached thereto by an attachment method such as melting.
• the implant 660 can be shape set to a 3D helical shape as in the implants described above. It should be understood that the inner braid 664 can be provided within the textile structure in any of the embodiments of the textile structure (e.g.,. outer braid) discussed herein.
• the implant 670 in the embodiment of Figure 37 has an outer tubular braid which can be the structure of the braided tube 12 or 12’ described herein, or any of the alternate structures, and is preferably an absorbent textile structure made of a plurality of yams formed from a plurality of filaments.
• An inner strand 674 preferably formed of a wire which is composed of a shape memory material such as Nitinol, although other materials are also contemplated, is positioned within the tubular braid 672. Note the strand 674 can be off center as shown.
• the inner strand 674 can provide the 3D shape for the implant 670 when placed in the aneurysm as it enables the tubular braid 672 to maintain its 3D shape.
• the strand 674 can be attached at each end to a radiopaque marker 676, 678.
• the braid 672 can be melted onto the wire strand 674 at its ends and/or other regions along its length to attach the strand 674.
• This overall softer implant 670 could facilitate packaging and delivery with the strand providing the sufficient rigidity for the 3D placement configuration of the implant 670.
• Figure 38 shows a cup that can be used with any of the implants described above.
• the cup 682 of the implant is configured to sit at the neck N of the aneurysm M to prevent the braid 684 of the implant from coming out of the aneurysm.
• the cup like member 682 is configured to appose the neck of the aneurysm and in some embodiments is composed of shape memory material such as Nitinol, although other materials are also contemplated.
• the cup like member 682 can be composed of a series of wire or fingers, spaced apart, and forming a cup shape with the free ends of the wire facing into the aneurysm.
• the tubular braid 684 is attached to the base of the cup 682 and is shown in its 3D helical configuration within the aneurysm M.
• the tubular braid 684 can be the structure of the braided tube 12 or 12’ described herein, or any of the alternate structures, and is preferably an absorbent textile structure made of a plurality of yams formed
• micrografts several embodiments of delivery systems of the present invention are disclosed. Many of the delivery systems enable over the wire insertion which minimizes micrograft snaking inside the catheter as well as enables delivery of longer length micrografts. The delivery systems also enable retrievability of the micrograft after partial deployment, and in some embodiments, even after full deployment.
• an intra- aneurysmal micrograft delivery system is illustrated and designated generally by reference number 54.
• the delivery system is described below for delivering micrograft 10 but it should be understood that it (as well as the other delivery systems described herein) can be used to deliver any of the micrografts disclosed herein.
• Delivery system 54 includes a pre-loaded delivery wire 62 for carrying the micrograft and a pusher catheter 58, the pre-loaded delivery wire 62 positioned within the pusher catheter 58.
• the system could include a loading sheath similar to the loading sheath of Figure 7 described below which is positioned thereover to retain the micrograft on the delivery wire 62.
• the individual components of the delivery system can be removed from the packaging during the procedure and assembled by inserting the delivery wire 62 proximally through the catheter 58 creating a junction 57 at the proximal end of the micrograft 10 and the distal end of the pusher catheter 58.
• they can be prepackaged with the delivery wire 62 already positioned within the pusher catheter 58 and a protective loading sheath similar to the loading sheath of Figure 7 positioned thereover to retain the micrograft 10 on the delivery wire 62.
• This delivery system may be used as a standalone delivery system to access the target anatomy, or with a microcatheter as described below. Any necessary flushing or coating activation can be done per physician’s discretion prior to insertion into the patient.
• Delivery wire 62 has micrograft 10 mounted thereon at region 56.
• Delivery wire 62 has a body with a length extending from proximal end 64 to distal end 66 can range between about 20 cm and about 400 cm, and more particularly between about 100 cm and about 300 cm, and even more particularly about 200 cm.
• Suitable diameters for the delivery wire 62 can range from about 0.0025 inches to about 0.040 inches, and more narrowly between about 0.002 inches and about 0.035 inches.
• the overall diameter of the delivery wire may be continuous, for example about 0.014” or the wire may taper from proximal to distal direction, for example about 0.007 inches to about 0.003 inches. Other sizes are also contemplated, dependent on the pusher catheter and/or microcatheter ID used for the procedure.
• the distal portion 68 of the delivery wire 62 can include a coil and the very distal tip 66 of delivery wire 62 can be bulbous, of increased diameter, or fitted with a marker band or coil.
• the distal portion 68 of the delivery wire may be radiopaque as well as able to be shape set to aid in tracking, vessel selection, and intra-aneurysm maneuvering.
• the distal portion can be shape set to J-shape as in Figure 11 A described below.
• the delivery wire 62 may also be coated with a hydrophilic coating.
• the delivery wire 62 includes a retaining structure such as a tapered region to aid in retention of the micrograft 10 thereon.
• a protective loading sheath can be utilized.
• the micrograft can be mounted using the micrograft introducer system 136 as described below with regard to Figure 9.
• Delivery wire 62 has a tapered region 70 (Figure 5C) forming an engagement structure for mounting the micrograft 10.
• a proximal stop collar 22 is positioned over the tapered region 70.
• the stop collar 22 can be attached to the delivery wire 62 or alternatively and preferably form a retaining feature attached to an internal portion of the micrograft 10. In either case, the proximal end of the micrograft 10 is frictionally engaged and retained by the delivery wire 62.
• Micrograft 10 is mounted coaxially (and slidably) on wire 62 a distance L from the wire distal tip 66.
• the distance L is set by the proximal stop collar 22 which interacts with wire taper 70 as shown in Figure 5C, or other hard stop on the wire (e.g., a marker band), and the overall length of the micrograft. For instance, longer micrografts may have a small distance L. In some embodiments, distance L may be zero and the hard stop may be on, inside or near the distal end of the micrograft 10 to interact with a bump, bulb or head (such has a head 184 of Figure 5E described below) on the distal end of the delivery wire 62 to prevent the delivery wire 62 from passing through the distal end of the graft. In this instance, the distal tip of the micrograft 10 would be adjacent the distal end of the delivery wire 62 as in the embodiment of Figure 5E.
• Figure 5C shows an enlarged cross sectional view of the proximal end of micrograft 10 with stop collar 22 engaging tapered region 70 of the delivery wire 62.
• the stop collar 22 as shown is in the form of a marker band to provide radiopacity for visualization.
• the wire taper 70 acts as a proximal stop to prohibit proximal movement of the micrograft 10 over the wire 62.
• proximal and distal Nitinol parts may be added to the micrograft as stops, or other parts and/or features (e.g., platinum marker band, notch, bump, etc.) can be added to the delivery wire to act as stops.
• the stop may be on the distal end of the braid (as mentioned above), the pusher catheter may act as the proximal stop, or the micrograft 10 can be sized to be free to slide across the entire length of the delivery wire, proximal to distal.
• the pre-loaded delivery wire 62 may be supplied with one or more micrografts covered by a protective cover such as cover 92 of Figure 7.
• This cover 92 has a tapered tip tapering to a smaller outer dimension for introduction into the lumen of a microcatheter or component thereof.
• more than one micrograft can be loaded on the delivery wire. They can be linked together on the delivery wire for delivery using one of the frayed, Velcro-like ends 38 described above with respect to Figure 3 or inter-connected with assistance of the coaxial delivery wire running through them. That is, the device can in some embodiments be supplied pre-packaged with a plurality of micrografts in line along the delivery wire.
• the delivery system 54 includes a pusher catheter 58 having a lumen through which the delivery wire 62 extends.
• Pusher catheter 58 includes a catheter body 72 and a Luer lock 74.
• Catheter body 72 is preferably of a variable stiffness construction with a stiff proximal section, softer mid-section and still softer distal section.
• Individual sections of the catheter may be made up of polymer tubing with varying durometers to control stiffness, proximal to distal.
• the body may also be made from a variable stiffness, laser cut tube made of stainless steel alloy or Nitinol, for example. If polymer tubes are used, the catheter may also be a braid or a coil reinforced to keep from ovalizing.
• a lubricous liner made from materials such as PTFE, ePTFE, or FEP may also be added to the structure.
• the outer diameter of the pusher catheter 58 is dimensioned to slide freely inside microcatheters with inner diameters ranging from about 0.008 inches to about 0.070 inches.
• Catheter body 72 can include a hydrophilic coating on its outer diameter for lubricity.
• the length of the catheter body 72 is preferably slightly shorter than the delivery wire 62 to allow proximal access to the delivery wire 62, i.e., holding the wire 62, while a micrograft (or multiple micrografts) is loaded on the distal end.
• the inner diameter of pusher catheter body 72 or the distal end is sized and shaped so that the micrograft 10 cannot be forced inside the catheter body 72 during distal advancement or proximal pulling of delivery wire 62.
• the delivery wire 62 When loaded in the pusher catheter 58, the delivery wire 62 is preferably free to rotate and to move in a linear (back and forth) motion relative to the pusher catheter 58. Additionally, the pusher catheter 58 can be designed to accommodate delivery of stents or other devices or fluids to the target anatomy. In some embodiments, a clearance between an outer dimension of the delivery member and an inner dimension of the occluding device is substantially fluid-tight before delivery into the aneurysm but sufficient to enable slidable movement of the delivery member with respect to the occluding device.
• radiopaque marker band 76 which can be made of platinum/iridium and attached with adhesive, heat shrink tubing, a swaging process, or other known methods. Alternatively, the marker band can be placed inside the pusher catheter 58 with the delivery wire 62 passing through it. Other suitable radiopaque materials for marker band 76 include gold, silver, and radiopaque shrink tubes, or metal coils for example.
• a luer lock 74 can be positioned at the proximal end of the catheter 58 and attached to the luer lock 74 is a rotating hemostatic valve (RHV) 78 for saline, drug, contrast media or other fluid introduction though the inner diameter of pusher catheter 58.
• RV rotating hemostatic valve
• the RHV 78 also serves as a lock to stop relative movement between the pusher catheter 58 and the pre-loaded delivery wire 62 when the RHV 78 is tightened over (clamped onto) the wire.
• the pusher catheter 58 can be delivered pre-packaged and sterile with an RHV as an accessory.
• a pusher catheter may not be required as after stent deployment by the stent delivery catheter, the micrograft loaded delivery wire can be inserted into the stent delivery catheter to deploy micrografts.
• the delivery wire 62 may be used as the primary access wire as in conventional guidewires.
• Figure 6 illustrates an alternate design to the over-the wire pusher catheter, which is a rapid exchange pusher catheter designated generally by the reference number 80.
• the rapid exchange (RX) pusher catheter 80 has a catheter body 82 with marker band 76 at a distal end and a stiff push wire 84.
• Catheter body 82 will share many of the same features as the mid and distal section of catheter body 72 described above, including coating.
• the stiff pusher wire 84 which may taper, can be made of stainless steel alloy, Nitinol, or other suitable material.
• the pusher wire 84 may alternately be a hypo-tube, with or without laser cutting, or a wire featuring a non-round cross-section.
• the device may be supplied pre-packaged and sterile.
• the RX catheter may be inserted over the delivery wire or guide wire before or after the aneurysm is accessed by the wire.
• FIG. 5E - 5G illustrate a delivery system 180 for delivering the micrograft 10’ of Figure 4 A.
• the delivery system has a pusher member 186 and delivery wire 182 with an enlarged head 184.
• the tab 29a of micrograft 10’ is bent downwardly and the delivery wire 182 passes through window 29b.
• the delivery wire 182 extends within micrograft 10’ to the distal end of the micrograft 10’.
• head 184 engages the proximal edge of stop 22, e.g., distal marker band 22, on micrograft 10’.
• the pusher member or catheter 186 has an internal stop 188 at its distal end to aid with pushing micrograft 10’ as well as to inhibit movement of micrograft 10’ into the pusher member’s inner diameter.
• the pusher catheter 186 is shown by way of example without a luer attachment. Both the pusher catheter 186 and the delivery wire 182 may be constructed as previously described.
• system 180 can include a protective introducer sheath similar to the loading sheath 92 of Figure 7 to limit micrograft movement as well as to assist in micrograft introduction into a microcatheter.
• the tab 29a provides a force against the delivery wire 182 to retain the micrograft 10’ on the wire 182.
• the wire 182 is retracted to the position of Figure 5F where delivery wire enlarged tip 184 engages the tab 29a. Up to this position the micrograft 10’ can be retrieved from the aneurysm and/or maneuvered therein.
• pusher catheter 186 is advanced (or wire tip retracted) to force the tab 29a to the position of Figure 5G, therefore enabling frill retraction of the enlarged head 184 of the delivery wire 182 through window 29b for release of the micrograft 10’ from the delivery wire 182.
• Figure 5H shows the tab 29a returned to its original position longitudinally aligned with the micrograft 10’ after retraction of the delivery system.
• FIG. 7 illustrates another embodiment of an intra-aneurysmal micrograft delivery system generally referred to by reference number 86.
• Delivery system 86 comprises a pusher wire 88 and a loading tube 92.
• Pusher wire 88 includes an elongate tapering flexible wire that can be made from stainless steel, or alternatively, Nitinol, plastic or other inert or biocompatible material or combination thereof. Although shown as a wire, the pusher wire can alternatively be a hypo-tube with a Luer lock.
• the pusher wire 88 can alternatively be a hypo-tube with a Luer lock.
• At the distal end of pusher wire 88 are expanding grasper members or arms 94, 98. Although there are four grasper arms in this design, more or less than four arms may be used.
• the arms 94, 98 can be made of shape set shape memory material such as Nitinol, spring tempered stainless steel, radiopaque metal, or other suitable material.
• the arms 94, 98 can alternatively be manufactured from a metal or elastic tube which is laser cut to create deflectable arms. Attached to the distal end of one or more of the grasper arms are radiopaque bands (see labeled bands 102, 106, and 108; the fourth band not shown since the fourth arm is not shown).
• the bands can be attached with glue, solder or other methods.
• the proximal ends of the arms are attached to the pusher wire 88 by a coil 110 which can be made of wound stainless steel or platinum iridium, for example.
• Attachment methods may include gluing, welding, or soldering.
• the use of the grasping arms has the advantage of enabling grasping of the micrograft after full deployment to retrieve/remove the micrograft or to maneuver/reposition the micrograft within the aneurysm as described below.
• the pusher wire 88 has a length (including arms) between about 20 cm and about 400 cm, more narrowly between about 100 cm and about 300 cm, for example about 200 cm. Suitable diameters for the pusher wire 88 can range from about 0.006 inches to about 0.040 inches, more narrowly between about 0.008 inches and about 0.035 inches. The overall diameter of the pusher wire 88 may taper from proximal to distal, for example about 0.014 inches tapering to about 0.003 inches.
• the pusher wire 88 either in part or whole, may be coated with a hydrophilic or PTFE coating for lubricity.
• Loading tube 92 is made of either metal or plastic and preferably has distal taper 112 for mating with a microcatheter Luer taper.
• the loading tube 92 preferably has a length sufficient to cover the entire micrograft 90 and at least a portion of coil 110.
• the inner diameter of the loading tube 92 is preferably close to the inner diameter of the microcatheter to which it will mate. A range for the inner diameter may be between about 0.008 inches and about 0.070 inches.
• the loading tube may have a crimp or other fixation method to prevent relative movement to the pusher wire 88.
• the introducer may have a lengthwise slit to aid in removal (i.e., peel-away).
• One way to load micrograft 90, which has proximal band 114, e.g., a marker band, is to position the loading tube 92 on pusher wire 88 just proximal to the two pair of grasper arms 94, 98 so that the arms are in their normal expanded position.
• the band 114 on micrograft 90 is then positioned between bands 102 and 104 (one on each arm of arms 94) and bands 106 and 108 of arms 98.
• the arms 94 can be shorter than arms 98 so the bands 102, 104 are proximal of bands 106, 108, or alternatively, the arms 94, 98 can be the same size and bands 102, 104 can be placed on a more proximal position of arms 94 (spaced from the distal end) while bands 106, 108 can be placed on a distal end or more distal position of arms 98.
• the loading tube 92 is then advanced forward (distally) compressing the pusher arms 94, 98 to a collapsed or compressed position to engage (grasp) the band 114 to retain the micrograft 90 in place.
• band 114 forms an engaging or retention structure for engagement by the pusher (delivery) wire 88 to retain the micrograft 90 on the wire 88.
• micrograft 90 is similar to micrograft 10 except for the proximal band 114 which is positioned around a portion of the braided structure.
• micrograft may have two proximal bands where the bands of the pusher wire sit to create a lock when compressed inside the lumen of the loading tube.
• a micrograft with an internal coil may have proximal coil windings spaced to have a gap that allows radial compression and grasping by the bands of the pusher wire.
• FIG 8 illustrates yet another embodiment of an intra-aneurysmal micrograft delivery system generally referred to by reference number 116.
• Delivery system 116 is a neurovascular stent-graft kit that comprises a pusher wire 118 with distal band 120, stent or flow diverter 122 with proximal arms with bands 124 and 126 and distal arms with bands 128 and 130, micrograft 132 with proximal band 134, and loading tube 133.
• the micrograft 132 is locked proximally by the stent 122 and stent bands 128 and 130 and loading tube 133.
• Stent or flow diverter 122 is in turn locked to pusher wire 118 using a similar locking concept as bands 124, 126 are blocked by band 120.
• Delivery system 116 can also be configured to have a through lumen for guidewire delivery.
• the delivery system 116 provides a single delivery system that can deliver a micrograft and a stent that can be combined on site to form a neurovascular stent-graft.
• the stent may be permanently attached to the pusher wire and acts as a temporary stent to push grafts into the aneurysm.
• FIG. 9 illustrates a micrograft introducer system 136 which may be used to mount micrografts on a delivery wire or on a guidewire before or during a medical procedure.
• Micrograft loader introducer system 136 comprises introducer sheath 138 loaded with micrograft 10.
• the introducer sheath includes tubular body 140, Luer lock 142, and stop tube 144.
• Tubular body 140 can be made of metal, plastic or a combination of materials and sized with an inner diameter between about 0.008 inches and about 0.070 inches and a length that covers all or substantially all of the micrograft 10.
• the distal tip of the tubular body 140 may be straight or tapered to help in micrograft introduction and handling.
• the Luer lock can be attached to an RHV such as RHV 78 of Figure 5D for the introduction of fluid such as, saline or contrast media, guide or delivery wires and pusher catheters.
• RHV such as RHV 78 of Figure 5D
• the stop tube 144 which is optional, has a through lumen and can be made of plastic or metal and may have a taper proximal to distal. The purpose of the stop tube is to prohibit the micrograft from exiting the tubular body 140 prior to loading and may be removed prior to insertion.
• FIG. 9 shows only one micrograft
• multiple micrografts may be delivered in a single introducer sheath. They may be free to move relative to one another or linked together using the frayed ends method, for example, as described above.
• Micrografts having secondary shapes will generally be linear or straight when loaded into the introducer sheath such that they are concentric.
• Introducer system 136 is delivered pre-packaged and sterilized. Once opened, an RHV and syringe may be attached to the Luer to introduce fluids.
• a delivery wire or guidewire may be pushed into the introducer sheath 138 to mount the micrograft(s) on the wire or alternatively the introducer sheath 138 may be mated with the proximal end of the microcatheter and the micrografts may be pushed proximally through the sheath 138 and into the microcatheter using a pusher catheter, with or without a wire, or with a commercially available pusher wire.
• micrografts disclosed herein can be preset to a non-linear configuration and advanced to the aneurysm in a substantially linear configuration and then return to the same non-linear configuration or different non-linear configuration when delivered into the aneurysm, depending on the space within the aneurysm.
• Figures 10 through 1 IF show the preferred method of using intra-aneurysmal micrograft delivery system 54 of Figure 5 A to deploy micrograft 10 of Figure 1. (Other micrografts described herein can be inserted in a similar fashion).
• the micrograft delivery method, as well as the“viscosity lock” function (described below) are depicted in flow chart form in Figures 18 and 19. Before implantation, the delivery system may be prepared prior to patient insertion as described above or as preferred by the physician.
• Typical intracranial aneurysm access requires inserting a guide catheter into the femoral artery and then tracking a microcatheter in combination with a primary guidewire through the vasculature until the aneurysm site is reached. Once there, the primary guidewire is removed and replaced with an embolization system.
• Figure 10 shows micrograft delivery system 54 of Figure 5 A being inserted as a unit into the proximal end of microcatheter 146 (with attached RHV 148), the microcatheter 146 having been inserted through the guide catheter and advanced to the aneurysm site and the primary guidewire removed.
• FIG 11 A illustrates the distal tip 66 of delivery wire 62 exiting microcatheter 146 that has been positioned inside aneurysm 150 and is held in place using a“jailing” stenting technique, surrounded by blood 152.
• Jailing refers to the use of a stent or flow diverter 154 to pin the distal tip of the microcatheter between the parent vessel intima and the stent or flow diverter 154, so that the microcatheter tip is held within the aneurysm and delivered occluding devices, e.g., micrografts 10, are kept out of the parent vessel lumen.
• Other techniques that may be used instead of jailing include temporary stenting and balloon remodeling. It is also contemplated that the micrografts of the present invention be deployed without the use of such parent vessel support (stent or flow diverter) devices.
• the exposed delivery wire tip 66 which has the pre-bent curve as shown, is slowly retracted into the micrograft 10.
• the retraction can be done in incremental steps of a few centimeters or completely until it reaches a location at, or near, the pusher/micrograft juncture 57 (see Figure 5A).
• blood 152 will be drawn into the micrograft’s inner lumen to fill the volume previously occupied by the delivery wire 62, as depicted in Figures 1 IB and 11C. This filling action occurs through a combination of the unique internal capillary features of the micrograft described earlier and due to a syringe-like“piston” effect of the receding wire.
• the micrograft 10 can be pushed forward off the wire 62 and into the aneurysm as illustrated in Figure 11D using the pusher catheter 58 ( Figure 5 A) as it is advanced distally and engages the proximal end of the micrograft 10.
• the micrograft 10 may still be retrieved due to a“viscosity lock” (described below) that is formed inside the microcatheter 146, between the delivery system components and micrograft, once surrounded by a viscous liquid (e.g., blood).
• a“viscosity lock” (described below) that is formed inside the microcatheter 146, between the delivery system components and micrograft, once surrounded by a viscous liquid (e.g., blood).
• This lock allows the micrograft 10 to be advanced and retracted while the proximal end of the micrograft 10 remains inside the lumen of the microcatheter 146 until desired placement is achieved.
• Micrograft 10 is pushed forward by pusher catheter 58 and the wire 62 can be pulled further proximally to junction 57, if it is not positioned there already. Once the wire 62 reaches junction 57, the inner lumen of the micrograft 10 will be completely filled with blood 152 that displaces the wire 62 and with any liquid that has been present (e.g., contrast). Since blood now fills the inside lumen of the micrograft 10 and has already permeated the braided walls via the aforedescribed capillary action, the saturated device is composed in part of the patient’s blood. Thrombosis and cell in-growth through the microporous yams will be accelerated as the blood becomes trapped and stagnant within the micrograft (implant) after delivery.
• blood 152 that displaces the wire 62 and with any liquid that has been present (e.g., contrast). Since blood now fills the inside lumen of the micrograft 10 and has already permeated the braided walls via the afore
• blood can enter the lumen of the micrograft 10 through a distal opening of the lumen and/or through other intermediate or proximal regions of the lumen spaced from the distal end as blood is absorbed through the braided structure. As blood enters such intermediate or proximal regions, it spreads in various dimensions as well as is directed proximally due to the aforedescribed capillary action.
• micrograft 10 As the micrograft 10 is deployed into the aneurysm, it will take on any preset secondary shapes and random shapes due to contact with aneurysm walls or the stent/flow diverter 154, as shown in Figures 11D and 11E. That is, in these Figures, micrograft 10 has a pre-set U-shape as shown, however, this shape can change as it contacts the aneurysm wall and/or stent 154. If the proximal end of micrograft 10 remains inside the microcatheter, the micrograft 10 can be retracted and repositioned at any time prior to full deployment as described above.
• FIG. 1 IE shows an enlarged cross section of the fully deployed pre-shaped blood filled micrograft 10 of Figure 1 ID.
• the delivery wire 62 and pusher catheter 58 are removed and, if needed, another micrograft 10 is loaded on the wire 62 or a new delivery system is opened, and the deployment process is repeated as described above.
• Multiple micrografts can be deployed by repeating the above steps until the aneurysm is sufficiently packed (per physician discretion) as shown in Figure 1 IF. If needed, the microcatheter tip or the delivery wire 62 can be used in between packing or during packing to move or compress micrografts within the aneurysm.
• microcatheter is removed and the stent or flow diverter 154 continues to expand to cover the neck of the aneurysm 158 to thereby block exit of the micrografts 10 from the aneurysm sac.
• micrograft 10 and stent or flow diverter 154 form neurovascular stent-graft 160, as shown in Figure 1 IF.
• delivery system 54 features a temporary liquid seal or “viscosity lock” effect inside the microcatheter which allows limited retrieveability (push/pull) of the micrograft during placement.
• The“pull” of the lock is generated by the tip of the pusher catheter 58, which creates a syringe-like“piston” within the fluid-filled microcatheter 146.
• Functionality of this lock is dependent on clearances between the microcatheter lumen, proximal micrograft 10 body, adjacent pusher 58 tip, the delivery wire 62, as well as the viscous and cohesive properties of the fluid medium.
• the flow chart of Figure 19 describes the steps of the viscosity lock function which are as follows:
• Push delivery system pushher 58 + wire 62 to advance micrograft 10 out of catheter 146.
• micrograft 10 While maintaining proximal end of micrograft 10 inside catheter 146, pull on delivery system to retract micrograft 10.
• viscous liquid i.e., blood
• viscous liquid i.e., blood
• it acts as a“gasket”, or a seal, around the pusher/micrograft junction 57 during any displacement (i.e., as the pusher is retracted).
• the action of pulling the pusher 58 (i.e., the piston) adjacent to the proximal end of the micrograft now creates a low pressure volume. This causes the micrograft(s) 10 suspended in blood to get suctioned and retract within the microcatheter 146.
• the micrograft 10 may also be retractable if the delivery wire distal tip 66 is pulled back proximal to the distal tip of pusher 58 or removed completely. High friction or pull resistance is more likely to break the“viscous lock”, so the preferred application for this retrieval method is with shorter, lower friction devices or where minimal tortuosity and resistive forces are involved.
• a pusher wire or delivery wire may not be present inside the micrograft lumen and internal filling of the micrograft with blood will be induced by pressure from the patient’s circulatory system or via capillary forces.
• Capillarity can be achieved by the micrograft having appropriately sized inner diameter or pores, as described earlier. Hence, the absorption of blood into micrograft depicted in Figure 11C can occur upon contact with blood even if delivery wire or external force is not used to draw blood in.
• Figure 20A-24 illustrate alternate embodiments of the delivery systems of the present invention having alternate locking systems which include a compression coil to apply a distally directed force on the micrograft to facilitate advancement to the target site.
• the coil is compressed by the micrograft when loaded in the delivery catheter and when the engaging member is released from engagement with the micrograft, the spring returns to its normal state to exert a force on the micrograft.
• Micrograft 100 identical to micrograft 10’ of Figure 4, except without the deflectable tab 29a, is shown in the delivery systems of Figures 21A-22C, 23 B, and 24, however, it should be understood, that the delivery systems of Figures 20A-24 can be utilized to delivery other micrografts disclosed herein, as well as other micrograft structures or other implantable devices.
• the locking system of Figure 20A is designated generally by reference numeral 190 and includes a compression coil 192 with a distal end 194, an elongated member in the form of a wire or ribbon 196 with a locking/engaging member in the form of a ball 198 at a distal portion, and a marker band 200.
• a hood 202 can be provided overlying the locking ball 198 and a portion of the lock wire 196 and coil 192.
• the locking ball 198 is configured to releasably engage the micrograft as described below.
• Compression coil 192 can be made of spring tempered stainless steel, Nitinol, polymers or any other material suitable for manufacturing compression coils, including radiopaque materials such as platinum/iridium.
• the compression coil in some embodiments has a length between about 2 mm and about 5 cm, more narrowly between about 3 mm and about 2 cm, for example about 5 mm.
• Suitable diameters for the compression coil 192 in some embodiments can range from about 0.006 inches to about 0.035 inches, more narrowly between about 0.010 inches and about 0.018 inches. Other lengths and diameters are also contemplated.
• the coil can be open or closed pitch and can have optionally square or ground ends which optionally can be welded, e.g. laser welded.
• hood 202 can be provided which extends over the top of locking ball 198.
• Hood 202 can be made of plastic or metal, but preferably the hood is made of plastic. It illustratively extends over the first 2 to 3 distal windings of coil 192, but can be made of different lengths to extend over a different number of coils.
• the hood 202 is secured to coil 192 by various methods such as melting it into the coil windings using a hot air source and removable shrink tube or other methods such as over molding.
• the hood 202 can extend distally beyond coil 192 and be cut at an angle (as shown), square, or flush with the coil depending on the mating component.
• the hood 202 limits vertical motion (i.e., transverse movement with respect to a longitudinal axis of the ball lock wire 196) of the locking ball 198 and keeps it from disengaging from the micrograft during tracking of the system through the vasculature to the target site.
• the hood 202 can have a smooth outer surface to reduce friction inside the catheter.
• An alternative way to control vertical (transverse) movement of the locking ball 198 is to add material (such as glue or solder) to the top surface of lock wire 196 or locking ball 198.
• the ball lock wire 196 with locking ball 198 can be made of material with a flat, round, or varying cross-section with one end of the material melted or formed to create the ball or enlarged feature.
• the lock wire material can be spring tempered stainless steel, Nitinol, polymer or any other material suitable for manufacturing ball-end wires, including radiopaque materials such as platinum/tungsten.
• the ball lock wire 196 can in some embodiments have a length equal to or longer than the length of the compression coil 192.
• the locking ball 198 at the end of the wire can in some embodiments have a diameter in the range of about 0.004 inches to about 0.040 inches, and more narrowly in a range of about 0.006 inches to about 0.012 inches.
• the locking ball 198 can be centered or offset relative to the longitudinal axis of the wire 196, depending on the structure it is intended to mate with. In the embodiment of Figure 20 A it is shown offset.
• the locking system sub-assembly of Figure 20 A can be assembled by inserting the ball lock wire 196 into the compression coil 192 and aligning it so that the locking ball 198 is covered by the hood 202.
• the locking ball 198 can be positioned inside the compression coil 192 or a distance away from the distal end 194 of coil 192 depending on desired coil compression (release force).
• the larger portion of the ball 198 (if offset) preferably faces down or away from the hood 202.
• An optional marker band 200 is partially or completely inserted into the proximal end of coil 192, pinning the wire 196 between the band 200 and the coil 192.
• the mated components are then soldered or glued to form a joint at the proximal end of compression coil 192 resulting in the locking system sub-assembly 190.
• the locking system sub-assembly 190 can be attached to a pusher wire 188 ( Figure 20A) similar to pusher wire 88 described in the embodiment of Figure 7 above except without the grasper arm.
• the pusher wire 188 can be solid if desired since a delivery wire need not be utilized.
• the locking system sub-assembly 190 can be attached to a pusher member or catheter such as pusher 189 of Figure 20B similar to pusher member 186 described in the embodiment of Figure 5E above.
• the pusher member 189 has a lumen extending therethrough for receiving a delivery wire.
• the distal end of the pusher wire 188 is slid through the marker band 200, which is positioned inside, and can extend partially outside (proximal) of proximal end of the coil 192, and soldered or glued in place to the marker band 200.
• the locking wire 196 is directly attached to the marker band 200 (and coil 192).
• the locking wire 196 can be directly soldered or otherwise attached to the pusher wire 188 (and coil 192).
• a shrink tube (not shown) can be melted over the proximal end of the joint to smooth out any edges and improve tracking around bends.
• the push wire 188 can be flattened or round at its distal end and a locking ball such as locking ball 198 can be formed on its tip, which would eliminate the need for ball lock wire 196.
• the locking system components can also be attached to the pusher wire individually and not as a sub-assembly as described above.
• the marker band 200 can have an open lumen to accept delivery wire 182 therethrough which also extends through a lumen in the pusher member 189.
• the band 200 extends slightly proximally from the proximal end of coil 192 so that it can be inserted into pusher member 189 for assembly.
• a shrink tube (not shown) can be melted over the proximal end of the joint to cover any edges and improve tracking around bends.
• the locking system components can also be attached to the pusher member individually and not as a sub-assembly as described above.
• FIG. 20B shows an alternate locking mechanism attached to pusher tube 189, but, as noted above, the locking mechanism 190 of Figure 20 A can be used with the pusher tube 189.
• the locking wire or ribbon (elongated member) of locking mechanism 191 instead of a locking ball, has a flat wire form 204 bent transversely (downwardly as viewed in the orientation of Figure 20B) with respect to the longitudinal axis. This forms a V-shaped hook like structure to engage the micrograft.
• this embodiment is shown in use with a delivery wire 182 such as the delivery wire 182 of Figures 5A-5E, which has an enlarged head 183.
• the locking subassembly includes a compression coil 192 positioned over the wire (or ribbon) 204 and marker band 200, with the longitudinally extending portion of wire 204 pinned between the coil 192 and marker band 200.
• the locking wire and locking ball may be formed from a single laser cut tube 218, as shown in the embodiment of Figures 22A-22C, which extends within, e.g., is concentric with, compression coil 192, the pusher member (e.g., pusher member 189 (not shown)), and tube 129’ of the micrograft 100 to aid in assembly and delivery.
• This is achieved by laser cutting a long thin section of tubing wall to make a locking wire 214 that transitions on the proximal end from a tube 218, while a distal end of the long thin section is melted into a lock ball 216.
• Laser cut tube 218 material is Nitinol, but it can be any other shape memory material, metal or polymer, or other materials, with sufficient flexibility and tensile strength.
• the locking ball may be formed by joining or melting a radiopaque material to the end of locking wire, such as soldering a platinum/iridium marker band to the distal tip of locking wire.
• the locking ball 216 is shown in engagement with a cutout in the tube 129’ of the micrograft.
• a compression coil 192 is assembled concentric with the wire 214 that is laser cut from tube 218.
• the tube 218 can be radiopaque to also function as a marker.
• Figures 21 A and 21B show locking sub-assembly 190 of Figure 20A without the use of the hood 202 and with the use of a delivery wire 182.
• the locking assembly 190 is fitted to a pusher member 189 and shown locked to the micrograft 100 by way of example.
• the locking assembly 190 is shown inside introducer sheath 208 (shown in cross section).
• Core element 101 (identical to core element 27 of Figure 4A) is positioned inside micrograft 100 (shown in cross section) and is connected to tube 129 (similar to tube 29 of Figure 4A but without the tab 29a) in a similar manner as core 27 and tube 29.
• Tube 129 has a window (opening) or cutout (slot) 206 forming a receiving portion therein configured to accommodate insertion (and releasable engagement) of locking ball 198 from the top (as viewed in the orientation of Figure 21 A).
• Proximal of window 206 on tube 129 is a marker band 22’ similar to marker band 22’ of the embodiment of Figure 4C, except having a lengthwise slot 210.
• the marker band 22’ can be attached to tube 129 via welding, soldering, adhesive, or other methods.
• Marker band slot 210 is sized and positioned such that the wire portion of ball lock wire 196 sits inside slot 210 when lock system is engaged with micrograft 100.
• Tube 129 may be laser cut from any metal tubing such as stainless steel or other alloys, like platinum/iridium or platinum/tungsten.
• delivery wire 182 is advanced past the distal end 194 of coil 192 and micrograft 100 is then slid over the delivery wire 182 until tube 129 comes in contact with locking ball 198.
• Tube 129 is then pushed further proximally (pushing locking ball 198 out of the way), pushing against distal end 194 of coil 192 causing the coil 192 to compress.
• lock ball 198 slips into and engages window (opening) 206 of tube 129.
• introducer sheath or catheter 208 is advanced over the assembly to prevent locking ball 198 from deflecting out of window 206 and to complete the lock.
• the lock is engaged as long as tube 129 and lock ball 198 remain inside the sheath 208.
• the compressed coil 192 returns to it normal non-compressed configuration, pushing tube 129 distally with a distally directed force, causing lock ball 198 to slip out and disengage micrograft 100 and pushing the micrograft 100 to the target site. (Note the delivery wire 182 is retracted from the micrograft 100).
• the coupling steps for locking a micrograft to the lock would be the same with the exception of inserting the delivery wire 182, which is absent in the push wire design.
• the micrograft would be released in the same fashion as described above as the ball is freed from the confines of the sheath (and hood if provided) to enable it to move laterally to disengage from the tube 129.
• the locking hook 204 of the embodiment of Figure 20B would be assembled/coupled to the micrograft in the same manner as described above (depending if attached to a pusher member 189 as in Figure 20B or attached to a pusher wire such as pusher wire 188 of Figure 20A).
• the micrograft would be released from the hook 204 in the same manner as the locking ball 198 is released from the sheath (and hood if provided) to enable it to disengage from the tube 129.
• Figures 22A-22C is similar to the embodiment of Figures 21 A and 2 IB, however, in addition to the slot 210 of marker band 22’, tube 129’ has a matching slot 212 as shown in the cross-sectional view of Figure 22 A which runs lengthwise from window (opening) 206 to proximal end of tube 129’. Otherwise, tube 129’ is similar to tube 129. Also, Figures 22A-22C differ, as noted above, as they depict a version of locking system 190 which has laser cut locking wire 214 and ball 216 formed from a single laser cut tube 218. Inside and outside dimensions of the laser cut tube 218 can overlap with those of tube 129.
• the dimension of tube 218 at wire region 214 could be greater or less than or equal to the dimension of tube 129’.
• Figure 22B provides an example where the dimension of wire portion 214 is less than the dimension of tube 129. Utilizing tubes of the same diameters prevents laser cut lock tube 218 and tube 129’ from stacking and achieves minimal radial profile while the lock wire and ball sit inside the slot and window of tube 29.
• the locking wire 192 extends external of tube 129 within slot 210 of marker band 22’, positioned between tube 129 and the inner wall of the sheath 208 while in Figure 22A, the locking wire 214 is internal of the marking band 22’ and extends in slot 212 of tube 129’.
• slot 210 and slot 212 form a V-shaped cross-sectional cut through the walls of marker band 22’ and tube 129, which gives the locking ball a tendency to slide radially toward the wider section of the slot while in tension (when the coil is compressed).
• the lock ball 216 diameter is large enough to prevent the ball from pulling out of the tube/marker band V-slot when the assembly is inside an introducer sheath or delivery catheter.
• the ball 216 will easily slip out and disengage from tube 129’ when the system is advanced out of sheath 208, with the compression coil 192 applying a pushing force on the released micrograft 100.
• This version of the locking system may be used with or without delivery wire 182.
• This slotted tube 129’ design can be used with any of the previously described locking ball or hook designs.
• FIG 23A and 23B show an alternative version of the locking system attached to a pusher wire 188.
• This version of the locking system has a lock wire (elongated member) 219 with a bend or elbow 220, bending at an angle to the longitudinal axis of the lock wire 219.
• ball 221 is inserted into tube 129 of micrograft 100 so that elbow 220 sits partially or completely inside the lumen of tube 129 with ball 221 positioned inside window 206 while coil 192 is compressed by the coupling of the micrograft; (coupled in a similar manner as described above).
• the assembly is constrained so that the curved lock wire 219 is hooked on tube 129 and micrograft; 100 is coupled for delivery.
• Advancing the system out of the sheath 208 causes the compressed coil to push micrograft 100 off the lock wire and detach (release) from the lock wire 219.
• engaging members are shown in the form of a ball lock or hook in the delivery systems described herein, other engaging structures are also contemplated. It should also be understood that the locking assembly described herein can be utilized with or without a delivery wire, and a hood can be provided in any of the systems.
• Figure 24 illustrates another embodiment of an intra-aneurysmal micrograft delivery system generally referred to by reference number 222.
• Delivery system 222 is designed to deliver a flow diverter 224 in combination with a micrograft 100 on a single delivery wire 226 using locking system 190 by way of example for micrograft attachment.
• One or more micrografts may be loaded on the delivery wire (using previously described methods) in tandem with a stent or flow diverter for more efficient delivery.
• a stent can be loaded within sheath 208. Note the flow diverter (or stent) is positioned proximal of the micrograft for delivery after delivery of the micrograft.
• lock ball arrangement of Figure 24 is shown, other locking systems described herein can also be utilized.
• the system 222 is introduced and tracked through a microcatheter which has been positioned with its distal tip in an aneurysm.
• the micrograft 100 would be deployed into the aneurysm first, the n the microcatheter tip would be pulled back into the parent vessel and positioned for delivery of the flow diverter (or stent).
• the flow diverter would then be delivered.
• locking system 190 and the delivery wire 226, can have coils distal of the flow diverter, and the coils and/or the flow diverter may be radiopaque to help identify wire position during interventional procedures.
• Figures 12A through 12C show directed delivery of micrograft 10 of Figure 1 inside an intracranial aneurysm. Other micrografts described herein can be delivered in a similar manner. Unlike micrograft delivery described in Figures 10 and 11A-11F above, in the embodiment of Figures 12A and 12B, the shaped delivery wire 62’ remains in the aneurysm so that the micrograft deployment can be directed to a targeted location (neck) within the aneurysm sac.
• Figure 12A illustrates a distal tip 66’ of delivery wire 62’ that has been shape set in a“J” and deployed so that the“J” points at the stent or flow diverter 154 covering the neck of the aneurysm. As the pusher catheter 58 is advanced distally, the micrograft 10 will deploy and follow along the delivery wire 62’ in a direction denoted by arrow 162 towards the stent or flow diverter 154.
• Figure 12B illustrates a delivery wire 62’ that has been shape set with a“J” and advanced into the dome of the aneurysm. As the micrograft 10 is advanced it will follow the curvature of the wire 62’ in a direction denoted by arrow 164.
• FIG 12C illustrates that the microcatheter 146 can be used to direct micrograft deployment within the aneurysm.
• the delivery wire has been pulled back into microcatheter 146 which is seated in the neck of the aneurysm 158.
• the tip of the microcatheter 146 can be curved to direct the micrograft 10.
• Figure 13 illustrates the deployment of flow directed micrografts 168 using intra- aneurysmal micrograft delivery system 54 with delivery wire 62’ having a“J” form at its tip and extending from microcatheter 146.
• Micrografts 168 can have the same structure as other micrografts described herein.
• Flow directed micrograft 168 can be any length, but shorter lengths such as about 2 mm to about 5 mm are utilized in this embodiment so as to move with blood flow. Since the flow directed micrografts 168 tend to be shorter than micrografts configured to fill the aneurysm, many more flow directed micrografts can be loaded onto the delivery wire and consecutively deployed, as illustrated in Figure 13.
• Micrograft 168 has been shape set into a“C” shape, however, other shapes are also contemplated as discussed above.
• micrograft 168 As each micrograft 168 is advanced distally off the delivery wire 62’, it will be caught up in blood flow exiting the neck of the aneurysm. Due to the stent or flow diverter 154 blocking the neck 158, micrograft 168 will be restricted from exiting into parent vessel 170. When a sufficient amount of micrografts 168 are introduced into the aneurysm, the micrografts will pile up and clog or create a localized graft at the stent/flow diverter and neck interface. Over time, thrombus will form above the clog to aid in closing off the aneurysm. The smaller, shorter micrografts are intended to provide a more complete obstruction or fill voids at the aneurysm neck.
• Figure 14 illustrates microcatheter 146 positioned inside the parent vessel 170.
• This embodiment differs from the previous embodiments in that instead of extending in the space between the stent 154 and parent vessel 170, the microcatheter 146 extends through the struts or pores of stent or flow diverter 154. In all other respects, the system is the same as that of the aforedescribed systems.
• micrograft 10 is shown exiting the microcatheter 146 into the aneurysm. Longer length or shorter length micrografts can be delivered.
• the delivery wire 62 can be a guidewire. Therefore, if desired, the micrograft delivery system with guidewire can be loaded into the microcatheter prior to catheter placement. The entire assembly, microcatheter and micrograft delivery system, can then be tracked to the aneurysm site using the delivery system’s guidewire as the primary tracking wire. Alternately, the guidewire and microcatheter can be tracked to the aneurysm site and rapid exchange catheter, e.g., pusher catheter 80 of Figure 6, can be advanced subsequently.
• rapid exchange catheter e.g., pusher catheter 80 of Figure 6
• FIG 15 illustrates the distal end of intra-aneurysmal micrograft delivery system 86 of Figure 7 deploying micrograft 90.
• Micrograft 90 has been released from arms 94, 98 and has assumed a pre-biased (pre-set) shape.
• the micrografts can be pre-set to a variety of configurations and the shapes illustrated in the drawings are provided by way of example.
• the micrograft 90 can be retrieved by capturing a portion of the structure between arms 94, 98, and advancing the microcatheter 146 over the arms to compress the arms.
• the delivery arms 94, 98 can be used to compress or move the micrograft around the aneurysm to aid in packing.
• Figure 18A provides a flow chart for one method of placing a micrograft of the present invention. This method utilizes the delivery system of Figures 5A and 5C. The steps include:
• Figure 18B provides a flow chart for another method of placing a micrograft of the present invention. This method utilizes the same delivery system of Figures 5E - 5H. The steps include:
• micrografts delivery systems and occluding devices (micrografts) disclosed herein have been described for use for treating intracranial aneurysms. It should be appreciated that the delivery systems and occluding devices (micrografts) can also be utilized for treating aneurysms in other regions of the body or for treating other vasculature or for treating non-vascular diseases.
• delivery systems disclosed herein can be utilized to deliver the various micrografts disclosed herein and specific micrografts discussed in conjunction with specific delivery systems are provided by way of example.
• micrograft may alternatively be constructed to mate with other microcoil delivery systems that provide a timed and controlled release, e.g., electrolytic detachment as described in U.S. Pat. No. 5,354,295 and its parent, U.S. Pat. No. 5,122,136, both to Guglielmi et al., interlocking ball and key way as described in U.S. Pat. No. 5,261,916 to Engelson, and pusher with mating ball configuration as described in U.S. Pat. No. 5,304,195 to Twyford et al.
• electrolytic detachment as described in U.S. Pat. No. 5,354,295 and its parent
• U.S. Pat. No. 5,122,136 both to Guglielmi et al.
• interlocking ball and key way as described in U.S. Pat. No. 5,261,916 to Engelson
• pusher with mating ball configuration as described in U.S. Pat. No. 5,304,195 to
• vaso-occlusive devices such as platinum microcoils may be used in combination with the micrografts of the present invention to occlude the aneurysm.
• the delivery systems disclosed herein are for uses for delivering devices for treating intracranial aneurysms, however it is also contemplated that the delivery systems can be used to deliver devices through and in other body lumens in a patient.

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