Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
  • A61B17/221—Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/32—Surgical cutting instruments
  • A61B17/3205—Excision instruments
  • A61B17/3207—Atherectomy devices working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions
  • A61B17/320725—Atherectomy devices working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions with radially expandable cutting or abrading elements
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
  • A61B17/22031—Gripping instruments, e.g. forceps, for removing or smashing calculi
  • A61B2017/22034—Gripping instruments, e.g. forceps, for removing or smashing calculi for gripping the obstruction or the tissue part from inside
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
  • A61B2017/22038—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for with a guide wire
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
  • A61B2017/22051—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation
  • A61B2017/22065—Functions of balloons
  • A61B2017/22067—Blocking; Occlusion

Definitions

• the present technology relates to the removal and/or retrieval of blood clots via mechanical extraction from within a blood vessel lumen.
• Venous thromboembolic disease represents a major source of post-traumatic, post-partum and in-hospital acquired morbidity and mortality.
• Clots that originate as Deep Vein Thromboses (DVT) in the lower extremity and less often in the upper extremity can cause limb swelling, tissue gangrene, chronic destruction of the venous valve system and long-term chronic conditions such as limb fatigue, edema and heaviness (collectively referred to as Post-Thrombotic Syndrome, PTS).
• PTS Post-Thrombotic Syndrome
• This represents a major detriment to quality of life amongst patients who develop a large DVT.
• a clot that develops in the upper or lower extremities poses a risk of clot migration that can lead to Pulmonary Embolism (PE).
• PE Pulmonary Embolism
• DVT and/or PE Conventional approaches to treating DVT and/or PE include clot reduction and/or removal.
• anticoagulants can be introduced to the affected vessel to prevent additional clots from forming, and thrombolytics can be introduced to the vessel to at least partially disintegrate the clot.
• thrombolytics can be introduced to the vessel to at least partially disintegrate the clot.
• Such agents typically take a prolonged period of time (e.g., hours, days, etc.) before the treatment is effective and in some instances can cause hemorrhaging.
• Transcatheter clot removal devices also exist, however, such devices are typically highly complex, prone to cause trauma to the vessel, hard to navigate to the pulmonary embolism site, and/or expensive to manufacture.
• Embodiments of the present technology are directed to systems and methods for treatment of deep vein thrombosis and/or pulmonary embolism.
• the subject technology is illustrated, for example, according to various aspects described below, including with reference to Figures 1-5.
• Various examples of aspects of the subject technology are described as numbered clauses (1, 2, 3, etc.) for convenience. These clauses can be combined with one another in any order and in any combination. These are provided as examples and do not limit the subject technology.
• a device for treatment of deep vein thrombosis or pulmonary embolism comprising: a core member having a distal portion; an inner member surrounding the distal portion of the core member, the inner member being slidably extendable along the core member distal portion; a helical outer member surrounding at least a portion of the inner member; and a flexible material extending between the inner member and the helical outer member.
• Clause 3 The device of any one of the preceding Clauses, wherein the flexible material comprises a sheet with one or more apertures formed therein.
• Clause 4 The device of any one of the preceding Clauses, wherein the one or more apertures define baffles in the sheet.
• Clause 6 The device of any one of the preceding Clauses, wherein a distal portion of the flexible material defines a closed-cell filter.
• Clause 7 The device of any one of the preceding Clauses, wherein the closed-cell filter is configured to prevent distal embolization of clot material.
• Clause 8 The device of any one of the preceding Clauses, wherein the flexible material comprises a polymer.
• Clause 9 The device of any one of the preceding Clauses, wherein the polymer comprises at least one of: urethane, polyethylene, expanded polytetrafluoroethylene (EPTFE), or polyethylene terephthalate (PET).
• the polymer comprises at least one of: urethane, polyethylene, expanded polytetrafluoroethylene (EPTFE), or polyethylene terephthalate (PET).
• Clause 10 The device of any one of the preceding Clauses, wherein the inner member comprises a coil having a first pitch in an unconstrained state, wherein the helical outer member has a second pitch in the uncompressed configuration, and wherein the second pitch is greater than the first pitch.
• Clause 11 The device of any one of the preceding Clauses, wherein the device has a low- profile configuration for advancement through a delivery sheath, and an expanded configuration for deployment at the treatment site.
• Clause 12 The device of any one of the preceding Clauses, wherein the helical outer member has a proximal end portion coupled to the inner member at a first point and a distal end portion coupled to the inner member at a second point.
• Clause 13 The device of any one of the preceding Clauses, wherein the core member comprises a polymer tube configured to be slidably advanced over a guidewire.
• Clause 14 The device of any one of the preceding Clauses, wherein the inner member comprises a metallic wire coil.
• Clause 15 The device of any one of the preceding Clauses, wherein the inner member comprises a shape-memory material.
• Clause 16 The device of any one of the preceding Clauses, wherein the inner member comprises stainless steel or nitinol.
• Clause 17 The device of any one of the preceding Clauses, wherein the helical outer member comprises a metallic wire.
• Clause 18 The device of any one of the preceding Clauses, wherein the helical outer member comprises a shape-memory material.
• Clause 19 The device of any one of the preceding Clauses, wherein the helical outer member comprises stainless steel or nitinol.
• Clause 20 The device of any one of the preceding Clauses, wherein the helical outer member has a curved radially outer surface configured to abut a vessel wall and a sharp radially inward edge configured to engage clot material.
• Clause 21 The device of any one of the preceding Clauses, wherein the sharp radially inner edge is configured to facilitate separating the clot material from the vessel wall.
• a system for treatment of deep vein thrombosis or pulmonary embolism comprising: a covering sheath having a lumen; a treatment device configured to be slidably received within the lumen for advancement to a treatment site, the treatment device comprising: a core member having a distal portion; an inner member surrounding the distal portion of the core member; a helical outer member surrounding at least a portion of the inner member, the helical outer member having a low-profile configuration for delivery through a catheter and an expanded configuration for deployment at the treatment site; and a flexible material extending between the inner coil and the helical outer member.
• Clause 23 The system of any one of the preceding Clauses, wherein the covering sheath has a diameter of approximately 6-9 Fr.
• Clause 24 The system of any one of the preceding Clauses, further comprising a delivery sheath having a lumen configured to slidably receive the covering sheath therein.
• Clause 25 The system of any one of the preceding Clauses, wherein the delivery sheath has a diameter of approximately 12-14 Fr.
• Clause 26 The system of any one of the preceding Clauses, wherein the delivery sheath comprises an expandable member disposed at a distal portion thereof.
• Clause 27 The system of any one of the preceding Clauses, wherein the expandable member comprises an expandable braided tip.
• Clause 28 The system of any one of the preceding Clauses, further comprising a guidewire, and wherein the core member comprises a polymer tube configured to be slidably advanced over the guidewire.
• a device for treatment of deep vein thrombosis or pulmonary embolism comprising: a core member configured to be positioned intravascularly at or adjacent a treatment site; an inner member coupled to the core member, the inner member configured to transition from a first axial length to a second axial length greater than the first; an outer member spirally winding around at least a portion of the inner member, the outer member having a low-profile configuration for delivery through a catheter and an expanded configuration for deployment at the treatment site; and a flexible material extending between the inner member and the outer member, the flexible material configured to engage clot material when the outer member is in the expanded configuration.
• Clause 30 The device of any one of the preceding Clauses, wherein the inner member comprises a coil.
• Clause 31 The device of any one of the preceding Clauses, wherein the inner member comprises a hypotube.
• Clause 32 The device of any one of the preceding Clauses, wherein the inner member is stretchable.
• Clause 33 The device of any one of the preceding Clauses, wherein the inner member comprises a plurality of discrete elements axially spaced apart along the core member.
• Clause 34 The device of any one of the preceding Clauses, wherein the outer member comprises a helically winding wire.
• Clause 35 The device of any one of the preceding Clauses, wherein the outer member comprises a shape-memory material.
• Clause 36 The device of Claim 28, wherein the outer member has a curved radially outer surface configured to abut a vessel wall and a sharp radially inward edge configured to engage clot material.
• Clause 37 The device of any one of the preceding Clauses, wherein the sharp radially inner edge is configured to facilitate separating the clot material from the vessel wall.
• Clause 38 The device of any one of the preceding Clauses, wherein the flexible material comprises a sheet with one or more apertures formed therein.
• Clause 39 The device of any one of the preceding Clauses, wherein one or more of the apertures are lined with a reinforcing material.
• Clause 40 The device of any one of the preceding Clauses, wherein the reinforcing material comprises a metallic material.
• Clause 41 The device of any one of the preceding Clauses, wherein the one or more apertures define baffles in the sheet.
• Clause 43 The device of any one of the preceding Clauses, wherein a distal portion of the flexible material defines a closed-cell filter.
• Clause 44 The device of any one of the preceding Clauses, wherein the closed-cell filter is configured to prevent distal embolization of clot material.
• Clause 45 The device of any one of the preceding Clauses, wherein the flexible material comprises a polymer.
• Clause 46 The device of any one of the preceding Clauses, wherein a length of the outer member is greater in the low-profile configuration than in the expanded configuration.
• Clause 47 The device of any one of the preceding Clauses, wherein the length of the outer member is at least twice as great in the low-profile configuration as in the expanded configuration.
• Clause 48 The device of any one of the preceding Clauses, wherein a distal end portion of the outer member is coupled to the inner member at a first point and a proximal end portion of the outer member is coupled to the inner member at a second point.
• Clause 49 The device of any one of the preceding Clauses, wherein, when the outer member transitions from the low-profile configuration to the expanded configuration, the first point and the second point move closer together.
• Clause 50 The device of any one of the preceding Clauses, wherein, when the outer member transitions from the expanded configuration to the low-profile configuration, the first point and the second point move further apart.
• Clause 51 The device of any one of the preceding Clauses, wherein the core member is configured to be slidably advanced over a guidewire.
• Clause 52 A method for removing clot material from a vessel lumen, the method comprising: advancing the device of any one of the preceding Clauses to a treatment site in the vessel lumen; and engaging clot material with the device.
• a method for removing a clot material from a vessel lumen comprising: advancing a treatment device disposed in a covering sheath through the vessel lumen to a treatment site adjacent the clot material, wherein the treatment device comprises: a core member having a distal portion; an inner member surrounding the distal portion of the core member; a helical outer member surrounding at least a portion of the inner coil; and a flexible material extending between the inner member and the helical outer member, wherein the helical outer member is in a low-profile configuration while disposed in the covering sheath; and releasing the treatment device from the covering sheath, thereby expanding the helical outer member from the low-profile configuration into an expanded configuration.
• Clause 54 The method of any one of the preceding Clauses, wherein releasing the treatment device from the covering sheath comprises retracting the covering sheath with respect to the treatment device.
• Clause 55 The method of any one of the preceding Clauses, wherein the covering sheath has a diameter of approximately 6-9 Fr.
• Clause 56 The method of any one of the preceding Clauses, wherein releasing the treatment device causes the helical outer member to engage the clot material.
• Clause 57 The method of any one of the preceding Clauses, wherein releasing the treatment device causes the helical outer member to penetrate the clot material.
• Clause 58 The method of any one of the preceding Clauses, wherein, after expanding the helical outer member from the low-profile configuration into the expanded configuration, the flexible material extends helically through the clot material.
• Clause 59 The method of any one of the preceding Clauses, wherein expanding the helical outer member causes at least a portion of the clot material to be engaged between adjacent spirals of the helical outer member.
• Clause 60 The method of any one of the preceding Clauses, wherein the flexible material comprises apertures, and wherein, after expanding the helical outer member from the low-profile configuration into the expanded configuration, at least a portion of the clot material extends through one or more of the apertures.
• Clause 61 The method of any one of the preceding Clauses, further comprising, after releasing the treatment device from the covering sheath, retracting the treatment device into a surrounding delivery sheath.
• Clause 62 The method of any one of the preceding Clauses, wherein retracting the treatment device into the surrounding delivery sheath comprises dislodging at least a portion of the clot material.
• Clause 63 The method of any one of the preceding Clauses, wherein retracting the treatment device into the surrounding delivery sheath comprises removing at least a portion of the clot material.
• Clause 64 The method of any one of the preceding Clauses, wherein the surrounding delivery sheath comprises an expandable tip, and wherein the expandable tip is in the expanded state while the treatment device is retracted into the surrounding delivery sheath.
• Clause 65 The method of any one of the preceding Clauses, wherein expanding the helical outer member causes at least a portion of the helical outer member to contact a vessel wall.
• Clause 66 The method of any one of the preceding Clauses, wherein expanding the helical outer member comprises expanding a distal embolic filter coupled to the helical outer member.
• Clause 67 The method of any one of the preceding Clauses, further comprising twisting the treatment device after releasing the treatment device from the covering sheath.
• Clause 69 The method of any one of the preceding Clauses, wherein releasing the treatment device from the covering sheath comprises releasing the treatment device in sequential stages.
• Clause 70 A system for staged compression of a clot prior to removal from the body over an endovascular system, the system configured to: prevent distal embolization; allow continuous hemostasis via an outer treatment sheath; and/or allow for multiple treatments to occur and maximize clot removal.
• Figure 1 illustrates a treatment system in accordance with aspects of the present technology.
• Figure 2 illustrates a treatment device engaged with a blood clot in accordance with aspects of the present technology.
• Figure 3 A illustrates another embodiment of a treatment device in accordance with aspects of the present technology.
• Figure 3B illustrates a cross-sectional view of the helical outer member taken along line 3B- 3B in Figure 3 A.
• Figure 4 illustrates the proximal end of the treatment system in accordance with aspects of the present technology.
• Figure 5 illustrates a method of manufacturing a treatment device in accordance with aspects of the present technology.
• Embodiments of the present technology are directed to systems and methods for treatment of deep vein thrombosis and/or pulmonary embolisms. Specific details of several embodiments of the technology are described below with reference to Figures 1-5.
• a treatment device as described herein can be used for clot removal of upper and lower extremity venous blood clots, and/or for clot removal from pulmonary arteries secondary to pulmonary embolism.
• the treatment device can be inserted over a guidewire via peripheral venipuncture in the upper or lower extremities, or via venipuncture of the internal jugular vein.
• the treatment device may also be used in any other vein or artery of the circulatory system where clot or other occlusive material is desired to be removed.
• the device can be configured to engage the clot and remove it via simple deployment and removal by a physician, without the need for complicated techniques or training.
• the device is configured to engage a clot which might fill a relatively large vessel, and to divide and linearize that clot into a longer, smaller-diameter form so that it can be removed through a sheath which is smaller than that large vessel.
• the treatment system allows a clinician to provide continuous hemostasis over a surrounding sheath during the procedure.
• a delivery sheath with an expandable tip
• the entire assembly including the clot, the treatment device, the covering sheath, and the delivery sheath
• the delivery sheath can be removed with a profile of between 12-14 Fr. This allows all the treatments to be performed through a larger (e.g., 16-18 French) access sheath.
• clot material can be removed via repeated treatments without dilating the vein at the access site.
• the outer access sheath remains intact, preventing unnecessary blood loss.
• the treatment device can include an inner member such as a coil mounted over a tube and an outer member such as a helically extending wire that surrounds the inner member.
• the outer member can be a shape-memory material that can assume a compressed, low-profile configuration for delivery and an expanded, deployed configuration with a larger radial dimension for engagement with a blood clot.
• a flexible material such as a polymer sheet can extend between the inner member and the outer member along at least a portion of their respective lengths. In the deployed state, the flexible material can extend into and adjacent the blood clot material to engage the blood clot material and facilitate its extraction and removal.
• the flexible material can have apertures that define baffles to provide improved engagement with the clot material.
• the treatment devices disclosed herein can be provided as one part of a treatment system, which includes: a treatment device 101, a covering sheath 103, an elongated delivery sheath 105, which may have an expandable braided tip 106 that can expand to accommodate a clot in the process of retrieval, and an atraumatic steerable guidewire 107.
• the covering sheath 103 is slidably received within a lumen of the delivery sheath 105.
• the treatment device can be slidably received within the lumen of the covering sheath, and a guidewire 107 can be slidably received within a lumen of the treatment device.
• the delivery sheath 105 can have a nominal diameter of approximately 12-14 Fr, and the covering sheath 103 can have a nominal diameter of between about 6-9 Fr, or approximately 8 Fr.
• the delivery sheath 105 can have an expandable tip 106 (e.g., a 2 cm braided tip) at its distal portion, for example a braid or a balloon that can be expanded into apposition against a surrounding vessel wall.
• the covering sheath 103 can have an expandable tip (e.g., a 2 cm braided tip) disposed at its distal portion.
• the bodies of the delivery sheath 105 and/or the covering sheath 103 can be made from various thermoplastics, e.g., polytetrafluoroethylene (PTFE or TEFLON®), fluorinated ethylene propylene (FEP), high-density polyethylene (HDPE), polyether ether ketone (PEEK), Polyether block amide (PEBAX), etc., which can optionally be lined on the inner surface or an adjacent surface with a hydrophilic material such as polyvinylpyrrolidone (PVP) or some other plastic coating. Additionally, either surface can be coated with various combinations of different materials, depending upon the desired results.
• PTFE or TEFLON® polytetrafluoroethylene
• FEP fluorinated ethylene propylene
• HDPE high-density polyethylene
• PEEK polyether ether ketone
• PEBAX Polyether block amide
• Figure 1 illustrates a treatment system 100, which includes a treatment device 101 slidably received within a surrounding covering sheath 103 and a larger-diameter delivery sheath 105.
• the covering sheath 103 can have a diameter of between about 6-9 Fr, or approximately 8 Fr. This would be used to deliver the treatment device 101 through the clot, as described in more detail below.
• the covering sheath 103 may remain proximal to the functional section of the treatment device 101 as tension is applied to the shaft of the treatment device 101 to draw the clot into the larger-diameter delivery sheath 105.
• the delivery sheath 105 can have a diameter of approximately 12-14 Fr in some embodiments, and may optionally include an expandable tip 106 (e.g., a 2 cm braided tip) capable of further capturing and compressing the clot to allow for seamless extraction.
• an expandable tip 106 e.g., a 2 cm braided tip
• a treatment device 101 (e.g., a treatment catheter) can include an elongated tubular shaft having a distally located functional portion 109.
• the treatment device 101 can be slidably advanced over a guidewire, and can also be slidably received within a surrounding covering sheath 103 and/or delivery sheath 105 for advancement to a treatment site.
• the functional portion 109 of the treatment device 101 can be restrained in a compressed, unexpanded, linearized, and/or low-profile configuration.
• the functional portion 109 of the treatment device 101 can assume an uncompressed, expanded, deployed, and/or helical configuration having a greater radially outermost dimension than in the compressed state.
• the functional portion 109 of the treatment device 101 can include one or more helically extending elements separated transversely by a flexible material such as a polyurethane sheet.
• the flexible material may be substantially continuous or can include one or more apertures along its length.
• the helically extending elements together may cause the functional portion 109 of the treatment device 101 to tend towards a pre-formed, generally spiral or helical shape.
• the functional portion 109 of the treatment device 101 is transformable between a delivery state having a low profile that is configured to pass through the vasculature and a deployed state having a radially expanded shape (e.g., generally spiral/helical or coil shape) in which the helically extending elements maintain the assembly in stable apposition with an inner wall of the target blood vessel.
• a radially expanded shape e.g., generally spiral/helical or coil shape
• the functional portion 109 of the treatment device 101 includes a coiled inner member 111 spirally wound around a central core member 115.
• a helical outer member 113 spirally winds around and surrounds the coiled inner member 111 and the central tubular member.
• the coiled inner member 111 and/or the helical outer member 113 can be made of nitinol, stainless steel, rigid polymers, or other suitable material.
• the diameter of the helical outer member 113 in the expanded state is approximately the same as the diameter of the vein or vessel at the treatment site.
• the helical outer member 113 has a diameter in the expanded, unconstrained state of around 12-14 mm, but may also function if constrained by smaller diameter vessels or due to engagement with clot material. Alternatively, the helical outer member 113 can be provided in different sizes for different target vessels.
• the helical outer member 113 and the coiled inner member 111 can be bonded together at the proximal and distal ends of the functional portion 109 of the device.
• the core member 115 can be an elastic polymer tube having a lumen that allows passage over a guidewire (e.g., over a minimum a 0.035" guidewire).
• the helical outer member 113 can have a significantly greater pitch than the more tightly wound coiled inner member 111.
• the coiled inner member 111 can be configured such that extension and contraction of the coiled inner member 111 does not substantially alter a radial dimension of the coiled inner member 111.
• the helical outer member 113 can be configured such that, when elongated, the helical outer member 113 assumes a reduced radial dimension, for example fully or partially linearizing such that the outer member 113 runs substantially parallel to the core member 115.
• the helical outer member 113 When the helical outer member 113 is compressed or is released from elongation, it may assume a deployed configuration with an increased radial dimension as shown in Figure 1.
• the length of the functional portion 109 is approximately 80 mm when unconstrained in the expanded, deployed configuration.
• the helical outer member 113 and the coiled inner member 111 may increase in length by between 50-100% of the unconstrained length.
• a sheet 117 of flexible material is coupled to both the coiled inner member 111 and the helical outer member 113 of the treatment device 101.
• the sheet 117 can be made of a polymer, for example urethane, polyethylene, expanded polytetrafluoroethylene (EPTFE), polyethylene terephthalalate (PET), or other biocompatible polymer. It may also be made of a flexible metal mesh or screen, such as a fine nitinol or stainless steel mesh.
• the sheet 117 can be attached to the helical outer member 113 while it is in an extended (e.g., linearized) state, such that when the helical outer member 113 assumes a helical or spiral configuration (such as during device deployment), the sheet 117 also forms a spiral helical strip.
• the sheet may have one or more apertures 119 (e.g., pores, perforations, slices, segments, twists, cups, or other features) along its length to allow it to engage the clot when it is deployed.
• the apertures may fully separate adjacent portions of the sheet 117 such that the sheet 117 includes multiple discrete sections extending between the inner member 111 and the outer member 113.
• the remaining material defined by the apertures 119 can form baffles 121 configured to engage clot material.
• a distal portion of the sheet has no apertures, thereby forming a closed-cell filter 123.
• This filter 123 can prevent distal embolization of clot material to more central veins, main pulmonary arteries, or sub-segmental pulmonary arteries.
• the treatment device 101 may be used in conjunction with intravenous or intra-arterial thrombolytic medication, while in other embodiments the treatment device 101 is configured to perform mechanical thrombectomy without the need for adjunctive care.
• a mechanism at the proximal end of the treatment device 101 may be provided to automate the deployment of the treatment device 101 to allow for a staged-ratio deployment, such that, for example, for every one centimeter of covering sheath 103 withdrawal, three centimeters of the treatment device 101 are exposed. This may optimize the radial expansion of the helical outer member 113 to ensure maximum contact with the vessel wall at the location of the thrombus, and thus maximum clot retrieval per treatment iteration.
• baffles 121 formed in the sheet 117 can be bolstered or manufactured with smaller radially directed nitinol wires that would allow for maximum envelopment of the central blood clot. This could in turn maximize clot compression for final extraction.
• a plastic coating to the helical outer member 113 can act as an outer soft protecting edge to protect the vessel wall, with an inner cutting edge such that if the device 101 is rotated it can separate the chronic fibrin from the vessel wall to facilitate clot retrieval.
• An alternative embodiment of the treatment device 101 may obviate the polymer baffles 121, using a simple helical outer member 113, affixed proximally and distally to a central guidewire or other centrally disposed anchoring member.
• an open-cell or closed-cell embolic protection cap may optionally be positioned at the distal -most aspect of the device 101.
• the coiled inner member 111 can be omitted or replaced with another suitable inner anchor configured to couple to the sheet of flexible material 117.
• the coiled inner member 111 could be replaced with a hypotube, with a series of discrete tubular elements or rings, or other elements mounted over the core member with some degree of freedom.
• the dimensions described herein relate to a device for removing clot from leg veins or pulmonary arteries. However, these dimensions could all be changed to make devices of other sizes to treat other vessels. For example, instead of an 0.035" guidewire, the device could be designed for delivery over an 0.018", 0.014", or even a 0.010" guidewire.
• Figure 2 illustrates clot material CM that is enveloped by the helical outer member 113 and baffles 121 that have been pulled proximally to help compress the clot material CM.
• the clot material CM is protected from distal embolization by the protective distal filter 123 and proximally is beginning to be compressed by the outer-most delivery sheath 105 in preparation for removal.
• the clot material CM may also be substantially elongated by the linearization of the helical outer member 113 and stretching of the coiled inner member 111 as it is withdrawn, which may substantially reduce the overall diameter of the clot material CM, allowing it to be more effectively drawn into the covering sheath 103 and/or the delivery sheath 105.
• the helical outer member As the helical outer member is linearized, the helical outer member and the coiled are pulled together into close apposition.
• the linear sheet of material whose edges are formed by the helical outer member and coiled inner member, thereby forms a relatively closed tubular pouch, which serves to enclose and retain the clot material CM as it is withdrawn from the vessel.
• FIG 3A illustrates an alternate embodiment of a treatment device 301 configured for removal of chronic fibrin-laden clots.
• the treatment device 301 includes an integrally formed embolic protection filter or umbrella 303 at the distal end of the device 301.
• the helical outer member 305 can be similar to the helical outer member 113 described above, except the helical outer member 305 illustrated in Figure 3 A is coated in a durable polymer.
• the helical outer member 305 can have a smooth, curved radially outer surface 305a configured to abut the vessel wall and a less curved inner surface 305b, thereby providing a leading edge 305c and a trailing edge 305d at the junctions of the two surfaces which can help separate chronic clot from the wall of the vessel.
• the helical outer member 305 can include only one of the edges 305c or 305d along some or all of its length.
• the radially inward facing surface 305b is not planar but has some curvature, yet still provides a cutting edge 305c and/or 305d where the inward facing surface 305b joins the curved outer surface 305a.
• the helical outer member 305 can include a ridge, protrusion, or other projecting element that forms a cutting member or cutting edge.
• Such a cutting edge can be particularly useful in separating a chronic fibrin clot from a vessel wall, for example allowing the device to be used for an endovenectomy.
• the helical outer member 305 can be urged forward and/or backward once in the expanded state such that the cutting edge is advanced axially into clot material.
• the cutting edge may face only in one axial direction - e.g., only distally facing or only proximally facing at any point along the helical outer member 305 or along all of the helical outer member 305.
• the outer helical member 305 can have one cutting edge facing distally and another cutting edge facing proximally, such that both proximal and distal movement of the helical outer member 305 enables the cutting edge to contact clot material.
• a unidirectional strut 307 which may be oriented proximally that is configured to open on removal of the covering sheath 103. This strut 307 may help to release the chronic clot from the wall and act as a“backstop” for the clot when the covering sheath 103 is being advanced prior to clot retrieval.
• FIG. 4 illustrates the proximal portion of the treatment system 100.
• a proximal portion of the treatment device 101 can extend proximally beyond proximal ends of the delivery sheath 105 and treatment catheter, allowing a clinician to manipulate the proximal end of the treatment system 100.
• a torque device 401 can engage the proximal portion of treatment device 101 to allow for some rotation of the device within the vessel to help orient the helical outer member 113 along the outer edge of the vessel and ensure maximum clot retrieval.
• the torque device 401 can be permanently coupled to the proximal portion of the treatment device 101, while in other embodiments the torque device is removable.
• the proximal portion of the treatment system 100 can include a first hub 403 and a second hub 405 configured to be positioned external to the patient.
• the first and/or second hubs can be coupled to the delivery sheath 105 and/or the covering sheath 103, and can include a hemostatic adaptor, a Tuohy Borst adaptor, and/or other suitable valves and/or sealing devices.
• the first and/or second hubs can further include an aspiration line coupled to a negative pressure-generating device, such as a syringe or a vacuum pump.
• the first and/or second hubs can include a port configured to receive one or more fluids before, during, and/or after the procedure (e.g., contrast, saline, etc.).
• the treatment device 101 Prior to delivery, the treatment device 101 can be withdrawn into the covering sheath 103 for initial delivery into the vessel. This linearizes the helical outer member 113 such that it assumes the low-profile, compressed configuration. For a helix which has a pitch approximately equal to its diameter, this helix may elongate by over three times its length when it is linearized. When the helix is linearized in the covering sheath 103, the coiled inner member 111 can stretch by an equivalent length.
• a procedure for using the treatment device can be as follows. First, the larger- diameter delivery sheath 105 is introduced into the vein or vessel. Then the treatment device 101 contained within the covering sheath 103 is introduced through the clot over a central guidewire.
• the helical outer member 113 and/or the inner member 111 can include radiopaque markers or can be formed at least partially of radiopaque material to facilitate visualization under fluoroscopy. Once the distal end of the covering sheath 103 is past the clot, the covering sheath 103 is gradually withdrawn, allowing the helical outer member 113 to expand into the clot.
• the handle at the proximal end of the treatment device 101 may have a mechanism which simultaneously advances the treatment device 101 while retracting the covering sheath 103.
• the treatment device may be configured to expand within the blood clot and into apposition with the vessel wall. Once deployed, a slight twisting motion or advancement or retraction may allow for more complete deployment of the treatment device 101 with the outer edge of the polymer- wrapped helical outer member 1 13 abutting the vein wall throughout the length of the clot.
• the clot may be cut into a spiral shape by the expansion of the helical outer member 113, and since the strip of flexible material 117 extends from the helical outer member 113 to the coiled inner member 111, the clot will be engaged by this strip of flexible material 117.
• Retrieval may then begin by pulling back proximally on the treatment device.
• the covering sheath 103 would move back with it, leaving the functional portion 109 of the treatment device out of the covering sheath 103.
• This retraction could be done manually or via a retraction handle at the hub of the catheter that would allow for precise tension on the helical outer member 113.
• the covering sheath 103 and/or the delivery sheath 105 may be advanced distally over the treatment device 101 to recapture or resheath the treatment device 101.
• the helical outer member 113 and coiled inner member 111 are retracted into the larger delivery sheath 105, they will both lengthen and partially linearize as they are stretched. This will also begin to cause the helical outer member 113 to pull away from the vessel wall and draw closer to the coiled inner member 111.
• the baffles 121 in the flexible material 117 between the coiled inner member 111 and the helical outer member 113 would then tend to engage the blood clot and begin to linearize the spiral clot to facilitate retrieval.
• the treatment device may then be slowly withdrawn into the larger delivery sheath 105.
• the helical outer member 113, the polymer baffles 121, and the closed cell polymer embolic-protection filter 123 each facilitate drawing the clot into the delivery sheath 105.
• the delivery sheath 105 could alternatively be advanced forward as the clot is captured, such that the expanding tip could help to further capture and compress the retrieved clot.
• the treatment device 101 and covering sheath 103 could then be completely withdrawn through the delivery sheath 105, or both the covering sheath 103 and the delivery sheath 105 with the treatment device 101 could then be removed through a larger access sheath over a wire, thus completing clot retrieval.
• the device could be cleaned and re-housed to allow for multiple treatment passes to be made.
• Figure 5 illustrates a manufacturing process for the functional section 109 of the treatment device.
• a helical outer member 113 e.g., a wire or other elongated structure
• a coiled inner member 111 at its proximal and distal end portions, for example via soldering, welding, adhesives, or other suitable fixation technique.
• this assembly can be twisted and pulled lengthwise to unwind the helix and straighten it, and the straightened helix is held in a fixture parallel to and an appropriate distance away from the coiled inner member 111, as depicted in Figure 5.
• a polymer tube may then be run through the lumen of the coiled inner member 111.
• a Teflon blocker tube may be inserted into the center lumen of this polymer tube to ensure an inner guidewire lumen diameter of at least approximately 0.040" to facilitate passage of an 0.035" or 0.038" guidewire.
• a sheet of flexible material 117 can then be wrapped around the helical outer member 113 and the coiled inner member 1 11 and sealed in place. The sheet 117 may be fused to itself as well as to the core member 115 to hold the assembly together. After the sheet 117 is fused, it can be trimmed and any desired slotting, baffling, twisting, cupping, perforating, or other processing of the polymer sheet can be performed to optimize its clot-engagement capabilities.
• this assembly When this assembly is released from the fixture, it returns to its helical shape around the coiled inner member 111, which forms a shape suitable for clot retrieval as described above.
• the distal aspect of the polymer may remain in a closed-cell fashion without baffles to provide a distal embolic filter 123.
• the proximal end of the assembly may then be attached to the shaft of the treatment device 101, for example by inserting and bonding the proximal extension of the coiled inner member 111 and/or the helical outer member 113 into the shaft of the treatment device 101.
• oval windows 119 seen in Figure 5 are examples of cut windows that allow for the remaining polyurethane“bridges” to act as baffles 121 that can engage and compress a clot when tension is pulled on the proximal end of the treatment device, straightening the helical outer member 113 and stretching the coiled inner member 111.
• Various other patterns of cuts, perforations, slices, or other openings can be provided to tailor performance of the remaining flexible material 117 in engaging clot material.

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• 2019
  • 2019-08-09 WO PCT/US2019/045941 patent/WO2020033853A1/en not_active Ceased
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