Classifications

• • 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
  • A61F2/95—Instruments specially adapted for placement or removal of stents or stent-grafts
• • 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
  • A61F2/95—Instruments specially adapted for placement or removal of stents or stent-grafts
  • A61F2/958—Inflatable balloons for placing stents or stent-grafts
• • 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
  • A61F2/95—Instruments specially adapted for placement or removal of stents or stent-grafts
  • A61F2/954—Instruments specially adapted for placement or removal of stents or stent-grafts for placing stents or stent-grafts in a bifurcation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/10—Balloon catheters
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M29/00—Dilators with or without means for introducing media, e.g. remedies
  • A61M29/02—Dilators made of swellable material
• • 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
  • A61F2/856—Single tubular stent with a side portal passage
• • 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
  • A61F2002/821—Ostial stents
• • 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
  • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2250/0014—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
  • A61F2250/0039—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis differing in diameter
• • 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
  • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2250/0058—Additional features; Implant or prostheses properties not otherwise provided for
  • A61F2250/006—Additional features; Implant or prostheses properties not otherwise provided for modular

Definitions

• the present invention relates generally to vascular catheterization, and specifically to intravascular balloons and stents.
• Intravascular stents are used for various purposes, including opening occluded blood vessels.
• the stent is supplied in a narrow, contracted form, with a deflated balloon contained inside the stent.
• the stent and balloon are held at the distal end of a catheter.
• the operator inserts a guide wire into the blood vessel, and then slides the catheter over the wire to position the stent in the proper location.
• the balloon is then inflated, via a channel in the catheter, causing the stent to expand so as to be anchored in place and hold the vessel open.
• the balloon is deflated and is withdrawn, along with the catheter, from the vessel.
• a balloon comprises a narrow inner part, for insertion into a side vessel at a bifurcation, and a collar, which surrounds one end of the narrow inner part of the balloon.
• the collar is configured to inflate to a larger diameter than the inner part.
• the narrow part of the balloon is inserted into the side vessel so that the collar is positioned at the ostium, where the side vessel joins the main vessel.
• Inflation of the balloon causes the inner part to expand within the side vessel, while the collar, whose inflated diameter is larger than the side vessel, remains in the main vessel.
• the inflated collar serves as a stopper against the ostium, and thus aids the operating physician in positioning the stent properly at the ostium.
• the balloon is used in implanting a stent in the side vessel, wherein one end of the stent protrudes from the side vessel into the main vessel and is expanded by the collar to a larger diameter than the rest of the stent in order to engage the ostium.
• An expandable ostial stent comprises a tubular body and a deformable flaring portion. Repair of a bifurcated vessel is accomplished by positioning the expandable ostial stent within a diseased portion of the bifurcation so that the flaring portion caps the ostium and the tubular body is seated within a side branch to the bifurcation, thereby completely repairing the vessel at the bifurcation without occluding blood flow.
• the stent delivery system comprises a stent delivery assembly having a distally-located deployment segment, which comprises a break segment which has an alterable configuration, as well as a stent-bearing segment.
• the break segment may be introduced into the patient in a first configuration. Then, when in proximity to the ostial lesion, the configuration of the break segment may be altered to assume a second, expanded, configuration which may be lodged against the wall of the parent conduit vessel, thereby localizing the ostium of the target vessel containing the lesion.
• One or more stents mounted, in a contracted configuration, on the deployment segment may then be deployed by expanding the deployment segment.
• the configuration of the break segment may then be reversed to assume the first (unexpanded) configuration, and the entire assembly may be withdrawn from the patient.
• U.S. Patent 5,632,762 whose disclosure is incorporated herein by reference, describes a specially tapered balloon for sizing an implantable tubular stent that has been positioned within an ostium.
• a stent is positioned within the right coronary ostium, and the tapered balloon is positioned within the stent to provide a radial outward flare on the proximal end of the stent.
• the proximal end of the stent is pressed back against the aortic wall surrounding the right coronary ostium, thereby minimizing any obstruction to blood flow in the aorta, and possibly reducing the risk of restenosis at the right coronary ostium.
• U.S. Patent Application Publication 2005/0177221 whose disclosure is incorporated herein by reference, describes a cardiovascular ostial stent, which includes two portions having different degrees of expandability.
• the distal portion has a normal degree of expandability to support a vessel.
• the proximal portion has a higher degree of expandability so that it can be formed into a flange-like structure.
• a balloon is designed to deploy the stent in a single operation.
• the balloon includes distal and proximal portions having different diameters corresponding to the distal and proximal portions of the stent.
• the distal portion is of normal diameter to deploy the distal portion of the stent in the vessel.
• the proximal portion is of greater diameter to form the proximal portion of the stent into the flange-like structure.
• a conventional stent is deployed through one branch (of a bifurcation, and then a second stent is deployed through a wall of the first stent and into the other branch.
• the flange-like structure on the a second stent secures the a second stent within the conventional stent.
• Embodiments of the present invention provide novel methods for treatment of vascular bifurcations, as well as stents, balloons, and ancillary components for use in such treatment.
• a method for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel, the first and second blood vessels having characteristic first and second diameters such that the first diameter is greater than the second diameter
• the method including: introducing a balloon in the first blood vessel into proximity to the vascular bifurcation, the balloon including an inner part and a collar proximal to the inner part; inflating the collar so that the collar expands to an expanded diameter greater than the second diameter but less than an outer diameter of an ostial funnel of the second blood vessel; advancing the balloon into the second blood vessel so that the inflated collar lodges within the ostial funnel; and while the inflated collar is lodged within the ostial funnel, inflating the inner part of the balloon so as to treat the second blood vessel.
• the method includes fitting a stent over the inner part of the balloon, wherein introducing the balloon includes deploying the stent within the second blood vessel, and wherein inflating the inner part of the balloon causes the stent to expand so that the stent is implanted within the second blood vessel.
• the stent includes proximal struts, and inflating the collar causes the proximal struts to expand to a size greater than the second diameter so as to engage the ostial funnel.
• the expanded struts do not extend into the first blood vessel.
• a method for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel, the first and second blood vessels having characteristic first and second diameters such that the first diameter is greater than the second diameter
• the method including: fitting a stent over a balloon, which includes an inner part and a collar proximal to the inner part, the stent including proximal struts that extend over the collar; introducing the balloon, with the stent fitted over the balloon, in the first blood vessel into proximity to the vascular bifurcation; inflating the collar so as to cause the struts to bend outward to an expanded diameter greater than the second diameter; advancing the inner part of the balloon, with the stent fitted over the balloon, into the second blood vessel so that the bent struts engage an ostium of the second blood vessel; and while the bent struts engage the ostium, inflating the inner part of the balloon so as to expand and implant the
• a method for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel, the first and second blood vessels having characteristic first arid second diameters such that the first diameter is greater than the second diameter
• the method including: fixing a stent to a distal end of a delivery catheter having an axis, the delivery catheter including resilient struts protruding radially outward from the axis at a location proximal to the stent to an expanded diameter greater than the second diameter; advancing the delivery catheter, with the stent fixed to the distal end thereof, into the first blood vessel through a guiding catheter, thus causing the struts to fold within the guiding catheter in a direction parallel to the axis while the delivery catheter is advanced through the guiding catheter; introducing the distal end of the delivery catheter, with the stent fixed thereto, distally out of the guiding catheter into proximity to the vascular bifurcation, thus permitting
• fixing the stent includes fitting the stent over a balloon at the distal end of the delivery catheter, and expanding the stent includes inflating the balloon.
• the method includes, after implanting the stent, withdrawing the delivery catheter from the first blood vessel through the guiding catheter, thus causing the struts to fold within the guiding catheter while the delivery catheter is withdrawn.
• a method for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel, the first and second blood vessels having characteristic first and second diameters such that the first diameter is greater than the second diameter
• the method including: fixing a self-expanding stent to a distal end of a catheter having an inflatable collar; deploying the distal end of the catheter, while holding the stent in a compact state, in the first blood vessel in proximity to the vascular bifurcation; inflating the collar while the distal end of the catheter is in proximity to the vascular bifurcation so that the collar expands to an expanded diameter greater than the second diameter; advancing the catheter into the second blood vessel so that the inflated collar engages an ostium of the second blood vessel; and while the inflated collar engages the ostium, releasing the stent so that the stent expands, thus implanting the stent within the second blood vessel.
• fixing the self-expanding stent includes fitting a sleeve over the self-expanding stent so as to hold the stent in the compact state, and releasing the stent includes withdrawing the sleeve from the second blood vessel while the stent remains within the second blood vessel.
• withdrawing the sleeve includes pulling the sleeve through a hub of the collar while the inflated collar engages the ostium.
• inflating the collar includes inflating the collar to an expanded diameter greater than the second diameter but less than an outer diameter of an ostial funnel of the second blood vessel, and advancing the catheter includes advancing the collar into the second blood vessel so that the inflated collar lodges within the ostial funnel.
• a method for treatment of a vascular bifurcation between first and second blood vessels including: using a catheter, introducing first and second balloon chambers into the first and second blood vessels, respectively, in an area of the bifurcation; and treating the bifurcation by selectively inflating the first and second balloon chambers 20 with a fluid via the catheter using a dual-channel manifold coupled to the catheter; and configuring the manifold so as to automatically limit a quantity of the fluid with which at least one of the first and second balloon chambers is filled to a predetermined volume.
• selectively inflating the first and second balloon chambers includes inflating the first balloon chamber to the predetermined volume, and thereafter 25. inflating the second balloon chamber.
• the method may also include deflating the first and second balloon chambers simultaneously.
• the first balloon chamber is configured as a collar surrounding a part of the second balloon chamber
• introducing the first and second balloon chambers includes inserting the second balloon chamber into the second blood vessel, while the part of 30 the balloon surrounded by the collar remains in the first blood vessel
• treating the bifurcation includes inflating the collar and bringing the inflated collar into engagement with an ostium of the second blood vessel before inflating the second balloon chamber.
• a method for producing a balloon including: fastening an inner part of the balloon around the catheter so as to seal the inner part to the catheter; forming an inflatable collar around the inner part by fastening a first end of the collar around the inner part so as to seal the collar to the inner part, and fastening a second end of the collar around the catheter so as to seal the collar to the catheter.
• the method includes providing inflation ports in the catheter through which the inner part and the collar can be independently inflated.
• fastening the first end of the collar includes folding the first end inward toward the catheter, and sealing the folded first end to a neck of the inner part of the balloon.
• a method for treatment of a vascular bifurcation between first and second blood vessels including: fixing first and second balloon chambers to a distal end of a catheter; fitting a retainer over the first and second balloon chambers; advancing the distal end of the catheter, while the first and second balloon chambers are contained within the retainer, into a vicinity of the bifurcation; releasing the first and second balloon chambers from the retainer in the vicinity of the bifurcation; and after releasing the first and second balloon chambers, deploying and inflating the first and second balloon chambers in the first and second blood vessels, respectively, in order to treat the vascular bifurcation.
• the retainer includes a sleeve. In another embodiment, the retainer includes a wire, which is wound around the first and second balloon chambers. Typically, releasing the first and second balloon chambers includes shifting the retainer in a proximal direction relative to the first and second balloon chambers.
• a method for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel including: implanting in the first blood vessel a first stent having a lateral opening, such that the lateral opening is aligned with the second blood vessel; fitting a second stent over a balloon, which includes an inner part and a collar proximal to the inner part, the stent including proximal struts that extend over the collar; positioning the balloon, with the second stent fitted over the balloon, in the lateral opening such that the inner part of the balloon protrudes through the lateral opening into the second blood vessel; inflating the collar within the first blood vessel so as to cause the struts to bend outward and engage the first stent in proximity to the lateral opening, whereby the second stent is positioned at a desired location in the second blood vessel; and while the bent struts engage the first stent, inflating the inner part
• positioning the balloon includes inserting a guide wire through the first blood vessel into the second blood vessel via the lateral opening in the first stent, and advancing the balloon over the guide wire.
• the proximal struts have differing respective lengths, which are chosen responsively to a branching angle of the bifurcation.
• apparatus for treatment of a vascular bifurcation where a second blood vessel branches -from a first blood vessel, the first and second blood vessels having characteristic first and second diameters such that the first diameter is greater than the second diameter
• the apparatus including: a balloon, including an inner part and a collar proximal to the inner part, wherein the collar is coupled to be inflated to an expanded diameter greater than the second diameter but less than an outer diameter of an ostial funnel of the second blood vessel; a catheter, which has a distal end to which the balloon is fixed, and which is configured for insertion through the first blood vessel into proximity with the vascular bifurcation and is operable to inflate the collar and to advance the balloon into the second blood vessel so that the inflated collar lodges within the ostial funnel, and to inflate the inner part of the balloon while the inflated collar is lodged within the ostial funnel so as to treat the second blood vessel.
• apparatus for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel, the first and second blood vessels having characteristic first and second diameters such that the first diameter is greater than the second diameter
• apparatus for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel, the first and second blood vessels having characteristic first and second diameters such that the first diameter is greater than the second diameter
• the apparatus including: a stent; a guiding catheter, which is configured to be introduced into the first blood vessel in proximity to the vascular bifurcation; a delivery catheter, which has an axis and a distal end to which the stent is fixed, and which is configured to pass through the guiding catheter into the first blood vessel, and which includes resilient struts at a location proximal to the stent, wherein passing the delivery catheter through the guide catheter causes the struts to fold in a direction parallel to the axis, and wherein upon emergence of the distal end of the delivery catheter distally out of the guiding catheter in proximity to the vascular bifurcation, the resilient struts protrude radially outward from the axis
• apparatus for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel, the first and second blood vessels having characteristic first and second diameters such that the first diameter is greater than the second diameter
• the apparatus including: a self-expanding stent; a catheter, having a distal end to which the stent is fixed in a compact state and which is configured for insertion through the first blood vessel into proximity with the vascular bifurcation so that the stent is inserted into the second blood vessel, the catheter including an inflatable collar proximal to the distal end, wherein the catheter is operable to inflate the collar while the distal end of the catheter is in proximity to the vascular bifurcation so that the collar expands to an expanded diameter greater than the second diameter and engages an ostium of the second blood vessel while the stent is released within the second blood vessel so that the stent expands, thus implanting the stent within the second blood vessel.
• apparatus for vascular treatment including: first and second balloon chambers; a catheter, having distal and proximal ends and containing first and second lumens coupled respectively to the first and second balloon chambers at the distal end of the catheter; and a manifold including first and second fluid channels coupled respectively to the first and second lumens at the proximal end of the catheter and operative to selectively inflate the first and second balloon chambers with a fluid via the catheter while automatically limiting a quantity of the fluid with which at least one of the first and second balloon chambers is filled to a predetermined volume.
• a medical device including: a catheter having a distal end; and a dual-chamber balloon fixed to the distal end of the catheter, the balloon including: an inner part, which is fastened around the distal end of the catheter so as to seal the inner part to the catheter; and an inflatable collar, which is formed around the inner part by fastening a first end of the collar around the inner part so as to seal the collar to the inner part, and fastening a second end of the collar around the catheter so as to seal the collar to the catheter.
• apparatus for treatment of a vascular bifurcation between first and second blood vessels including: a catheter having a distal end; first and second balloon chambers, which are fixed to the distal end of a catheter; a retainer, which fits over and contains the first and second balloon chambers while the distal end of the catheter is advanced into a vicinity of the bifurcation, and which is operable to release the first and second balloon chambers in the vicinity of the bifurcation, so that the first and second balloon chambers can be deployed and inflated in the first and second blood vessels, respectively, in order to treat the vascular bifurcation.
• apparatus for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel including: a first stent, which has a lateral opening and is configured to be implanted in the first
• a balloon which includes an inner part and a collar proximal to the inner part
• a second stent which includes proximal struts and is fitted over the balloon so that the struts extend over the collar
• a catheter having a distal end to which the balloon is fixed, and which is operative to position the balloon, with the second stent fitted over the balloon, in the lateral opening such that the inner part of the balloon protrudes through the lateral opening into the second blood vessel, and to inflate the collar within the first blood vessel so as to cause the struts to bend outward and engage the first stent in proximity to the lateral opening, and to inflate the inner part of the balloon while the bent struts engage the first stent so as to expand and implant the second stent within the second blood vessel.
• a method using first and second stents for treatment of a vascular bifurcation where a first blood vessel branches from a second blood vessel, the first stent having a lateral opening including: fitting the second stent over a balloon, which includes an inner part and a collar proximal to the inner part, the stent including proximal struts that extend over the collar; positioning the balloon, with the second stent fitted over the balloon, in the vascular bifurcation so that the inner part of the balloon protrudes into the second blood vessel while the collar is in the first blood vessel; after positioning the balloon, inflating the collar within the first blood vessel so as to cause the struts to bend outward and engage a wall of the first blood vessel in proximity to the bifurcation, whereby the second stent is positioned at a desired location in the second blood vessel; and while the bent struts engage the wall of the first blood vessel, inflating the inner
• apparatus for treatment of a vascular bifurcation where a second blood vessel branches from a first blood vessel including: a first stent, which has a lateral opening and is configured to be implanted in the first blood vessel such that the lateral opening is aligned with the second blood vessel; a balloon, which includes an inner part and a collar proximal to the inner part; a second stent, which includes proximal struts and is fitted over the balloon so that the struts extend over the collar; and a catheter, having a distal end to which the balloon is fixed, and which is operative to position the balloon, with the second stent fitted over the balloon, in the vascular bifurcation so that the inner part of the balloon protrudes into the second blood vessel while the collar is in the first blood vessel, and to inflate the collar within the first blood vessel so as to cause the struts to bend outward and engage a wall, of the first blood
• FIGs. I 5 2, 3 A, 4 and 5 are schematic, pictorial illustrations showing stages in a procedure for implanting a stent in a vascular bifurcation, in accordance with an embodiment of the present invention
• Fig. 3B is a schematic side view of a balloon and stent within a vascular bifurcation during a stage in a procedure for implanting the stent in the bifurcation, in accordance with an embodiment of the present invention
• Fig. 6 is a schematic side view of a balloon assembly mounted on a catheter, in accordance with an embodiment of the present invention
• Fig. 7 is a schematic detail view of the assembly of Fig. 6;
• Fig. 8 is a schematic, exploded view of a manifold for controlling inflation and deflation of a balloon assembly, in accordance with an embodiment of the present invention
• Fig. 9 is a schematic, pictorial illustration showing details of a flow control mechanism, in accordance with an embodiment of the present invention
• Figs. 10-15 are schematic, pictorial illustrations showing stages in a procedure for implanting a stent in a vascular bifurcation, in accordance with another embodiment of the present invention
• Figs. 16-19 are schematic, pictorial illustrations showing stages in a procedure for implanting a stent in a vascular bifurcation, in accordance with yet another embodiment of the present invention
• Figs. 20-22 are schematic, pictorial illustrations showing stages in deployment of a bifurcated balloon within a vascular bifurcation, in accordance with an embodiment of the present invention
• Fig. 23 is a schematic side view of a stent for implantation in a vascular bifurcation, in accordance with an embodiment of the present invention.
• Figs. 24-27 are schematic, pictorial illustrations showing stages in a procedure for implanting a stent in a vascular bifurcation, in accordance with still another embodiment of the present invention.
• Figs. 1, 2, 3 A, 3B, 4 and 5 schematically illustrate successive stages in implantation of a stent 20 within a side vessel 22 at a bifurcation from a main vessel 24, in accordance with an embodiment of the present invention.
• Figs. 1, 2, 3 A, 3B, 4 and 5 are pictorial illustrations, while Fig. 3B is a side view.
• Stent 20 comprises struts 28 for engaging an ostium 26 of side vessel 22, as shown in these figures and described hereinbelow.
• This implantation procedure may be used in substantially any bifurcation, but it is especially useful for treating bifurcations from large arteries, such as the bifurcation of the coronary arteries from the ascending aorta.
• the inventors have found that the side vessels in such bifurcations tend to have an ostium 26 whose shape is approximately conical. Methods that have been known in the art for implanting stents in these bifurcations have failed to take this characteristic of the vascular anatomy into consideration.
• the present embodiment is designed to accommodate the conical shape of the ostium and thus achieves more accurate and secure stenting in the area of the bifurcation than do methods and devices known in the art.
• stent 20 in a contracted state, is fitted and crimped over a deflated balloon 30.
• This balloon comprises two parts with different inflation characteristics: an inner part 32, made of semi-compliant material, and a collar 34, made of more highly compliant material, which surrounds the proximal end of inner part 32.
• balloon 30 comprises a biocompatible nylon-based copolymer or other suitable biocompatible material.
• inner part 32 and collar 34 may be fabricated as separate balloons, with the collar having the general form of a toroid fitted around the inner part. Details of the construction of balloon 30 are shown in Figs. 6 and 7 and are described hereinbelow with reference to these figures.
• Inner part 32 and collar 34 may share a common inflation port, or they may alternatively have separate inflation ports, enabling the two parts to be inflated to different pressures.
• a dual-port manifold that may be used to inflate and deflate balloon 30 is described hereinbelow with reference to Figs. 8 and 9.
• Stent 20 is crimped over balloon 30 so that struts 28 extend over inner part 32 of the balloon and over at least the distal part of collar 34.
• the stent is delivered via a guiding catheter 36 over a guide wire 38, which has been threaded from main vessel 24 into side vessel 22.
• balloon 30 has a central lumen with a distal opening for accommodating the guide wire.
• the catheter in this embodiment and in the other embodiments described hereinbelow
• the balloon may be adapted to operate without the use of a guide wire.
• the balloon may include a built-in wire as an integral part of its assembly.
• collar 34 of balloon 30 is inflated, causing struts 28 to bend apart so as to reach an overall diameter greater than the diameter of side vessel 22.
• Two alternative options may then be used for positioning the stent in the side vessel: • As shown in Fig. 3 A, collar 34 may be at least partially deflated, while struts 28 remain bent outward. The operating practitioner at this stage pushes the catheter forward, in the distal direction, so that struts 28 engage ostium 26.
• the catheter may be advanced while collar 34 remains inflated, until the collar and struts 28 engage ostium 26.
• the collar is sized and shaped so that it fits into the conical funnel formed by ostium 26, rather than pressing against the wall of main vessel 24 as in the publications mentioned in the Background of the Invention.
• the diameter of the balloon is less than the outer diameter of the cone, of the ostial funnel (also referred to hereinafter simply as the "ostial cone"), so that the balloon lodges within the cone.
• the collar may also be made sufficiently flexible (by controlling inflation pressure, for example) so that it deforms to fit the shape of the funnel when pushed against it. The inventors have found that choosing the proper size, shape and degree of flexibility of collar 34 are useful in ensuring accurate placement of the stent in vessel 24.
• the stent may simply be fitted over inner part 32 of balloon 30, without struts extending over collar 34, so that the collar alone engages the ostial cone.
• the use of struts 28 and/or collar 34 to engage the ostial cone ensures that stent 20 is properly positioned for expansion inside side vessel 22.
• the struts bend smoothly against the conical sides of the ostium, rather than protruding into main vessel 24 and bending back against the wall of the main vessel as in methods that are known in the art.
• Engaging the funnel rather than the wall of the main vessel, gives the operator more precise control over the positioning of the stent, with better assurance that the stent will be properly positioned and lodged firmly in place at the end of the procedure.
• the size, shape and flexibility of the collar are chosen to fit the size and shape of the ostial funnel.
• inner part 32 of balloon 30 is fully inflated, causing the balloon to assume the shape shown in Fig. 4.
• Collar 34 may remain inflated during this stage, or it may alternatively be partly or completely deflated as shown in the figure.
• the inner part of the balloon expands the main body of stent 20, to support vessel 22.
• struts 28 press against ostium 26 to support the ostium and help to hold the stent in place.
• Both the main body of stent 20 and struts 28 may elute an anti-restenosis drug into the adjacent tissue.
• Balloon 30 is then deflated, as shown in Fig. 5, and withdrawn from the body through vessel 24 by using catheter 36.
• FIG. 6 is a schematic side view showing the mounting of inner part 32 and collar 34 on a shaft 40 of a delivery catheter (which is located inside guiding catheter 36 in Figs. 1-5).
• Shaft 40 contains a guide lumen 42, which passes through balloon 30 and is designed to be threaded over guide wire 38.
• the catheter also contains inflation lumens 46 with ports for selectively inflating and deflating inner part 32 and collar 34.
• Fig. 7 shows details of the area in which balloon 30 is fastened to catheter 40.
• inner part 32 and collar 34 are fabricated from a nylon-based copolymer or other suitable biocompatible material.
• Inner part 32 is sealed around the circumference of catheter 40, typically by heat fusing, using a laser as a heat source, or alternatively using conductive or convective heating. Further alternatively, the seal may be produced using polymer-to-polymer glue.
• Collar 34 is similarly fitted around catheter 40 and is folded inward around the neck of inner part 32. The collar is then fastened and sealed to the inner part of the balloon by heat fusing or glue to form a joint 44.
• proximal neck of balloon 34 is fastened (by heat fusing or glue) to catheter 40, as shown in Fig. 6.
• the inventors have found that this arrangement permits the two parts of balloon 30 to be formed efficiently and compactly, and gives reliable performance when the parts of the balloon are inflated.
• Figs. 8 and 9 are schematic, pictorial illustrations of a manifold 50 that may be used to inflate and deflate balloon 30, as well as other dual- chamber balloons, in accordance with an embodiment of the present invention.
• Fig. 8 is an exploded view of the manifold, while Fig. 9 shows details of its internal construction.
• manifold 50 connects to a fluid supply inlet 52, which provides a pressurized supply of a suitable fluid, which may be a liquid, such as saline solution, or a suitable gas.
• a suitable fluid which may be a liquid, such as saline solution, or a suitable gas.
• the manifold connects to a dual-lumen fluid delivery outlet 54, which connects to the dual chambers of balloon 30 through catheter 36, for example.
• Manifold 50 comprises two fluid channels 60 and 62, for feeding collar 34 and inner part 32 of the balloon, respectively. Each channel is controlled independently to convey a different volume of fluid, which may be determined according to the desired volume and pressure to which the corresponding part of the balloon is to be inflated. Manifold may be arranged so that both parts of the balloon are inflated and deflated simultaneously, in a single inflation or deflation procedure, hi the embodiment shown in the figures, however, manifold 50 comprises a switch 56, which operates a valve (not shown) that allows the user to selectively inflate either the proximal (collar) or distal (inner part) of the balloon.
• a switch 56 which operates a valve (not shown) that allows the user to selectively inflate either the proximal (collar) or distal (inner part) of the balloon.
• switch 56 is shown in the figure as having the form of a lever, it may alternatively have a push-button design. Additionally or alternatively, while the valve operated by switch 56 is designed to permit the parts of the balloon to be inflated individually, one at a time, it may allow both parts of the balloon to be deflated simultaneously to facilitate rapid removal of catheter 36.
• a flow control mechanism 58 applies automatic volume restriction to one of the channels - in this case channel 62, which feeds collar 34. Volume restriction is useful in ensuring that the collar is inflated to the optimal size and pressure for engaging ostium 26. (Similar volume restriction could be applied to distal channel 60, but in this embodiment the practitioner operating catheter 36 is permitted to inflate the inner part of the balloon freely to whatever pressure is desired.)
• the volume of fluid passing through channel 62 is measured by a turbine flow meter 64, which is connected through a rotary-to-linear transmission 66 to a rotary-actuated valve 70. After a predetermined number of turbine rotations (which represents a predefined flow volume), an actuator notch 68 driven by transmission 68 turns valve 70, thereby shutting off the fluid flow.
• Mechanism 58 is advantageous in terms of its simplicity and low cost.
• other types of flow control mechanisms known in the art may be used to measure and restrict the volume of fluid passing through channel 62 and/or channel 60, including electronic devices, as well as purely mechanical devices such as that shown here.
• Figs. 10-15 are schematic, pictorial illustrations showing successive stages in implantation of a stent 80 within side vessel, 22, in accordance with another embodiment of the present invention.
• stent 80 is initially crimped over a balloon 84 and is delivered to the region of the bifurcation of vessel 22 from vessel 24 by a guiding catheter 82 along guide wire 38.
• the operator advances a catheter 88 (which may be referred to for clarity as the "delivery catheter") in order to push stent 80 and balloon 84 distally out of the guiding catheter and into vessel 22, as shown in Fig. 11.
• Flexible struts 86 are attached to the shaft of catheter 88 at a point proximal to balloon 84. These struts are typically made of a resilient material, such as NiTi. The struts are formed so that when released from guiding catheter 82, they spread apart, away from the axis of catheter 88, as shown in Fig. 12. As the delivery catheter is advanced, the struts are thus exposed (Fig. 11) and then released (Fig. 12), so that they protrude radially to a diameter that is greater than the diameter of side vessel 22. Prior to deployment, struts 86 may also be secured with a sleeve or sheath (not shown) in order to protect the struts from unwanted deformation. In this case, the flexible struts may be bent in the distal direction prior to deployment, rather than in the proximal direction as shown in the figures.
• struts 86 engage the wall of main vessel 24 and/or ostium 26.
• the conical shape of the ostium bends the struts backward toward guidance catheter 82, as shown in Fig. 13.
• Struts 86 are made sufficiently stiff so that the operator can feel the resistance of the struts while pushing catheter 88 distally into side vessel 22, and can thus position stent 84 precisely at the end of the vessel near the bifurcation.
• the operator Upon finding the desired position, the operator inflates balloon 84, thus expanding stent 80, as shown in Fig. 13.
• catheter 88 with struts 86 may be used, mutatis mutandis, in deploying a self-expanding stent, such as that shown below in Figs. 16-19.
• a self-expanding stent such as that shown below in Figs. 16-19.
• Figs. 16-19 are schematic, pictorial illustrations showing successive stages in operation of a stent delivery system 90, in accordance with yet another embodiment of the present invention.
• system 90 is designed to deliver a stent 94 that is self-expanding.
• stent 94 may comprise a superelastic material, such as NiTi, as is known in the art.
• the stent is contained within a sleeve 96 as it is advanced through the vascular system to a vascular bifurcation by a delivery catheter 92. It is thus held in a compact state until it reaches the proper location.
• the operator advances catheter 92 to position system 90 in proximity to the target bifurcation (as was shown in the preceding embodiments).
• the operator may use a radio-opaque marker under angiography, for example, in order to visualize the location of the stent.
• the operator inflates a positioning balloon 98 through a dedicated lumen (not shown) in the delivery system, so that the balloon assumes the shape shown in Fig. 17.
• the operator then continues to advance the catheter until balloon 98 engages the ostium, at which point the system cannot be advanced any further.
• stent 94 To release and deploy stent 94 in the side vessel, the operator pulls sleeve 96 back through the hub of balloon 98, as shown in Fig. 18. After the sleeve has been retracted, stent 94 expands to the full diameter of the side vessel, as shown in Fig. 19. Balloon 98 is then deflated, and system 90 is withdrawn through the vascular system while leaving stent 94 in place.
• stent 94 is shown in this figure as having a uniform expanded diameter over its entire length, the stent may alternatively have proximal struts or other elements that expand to a greater diameter in order to engage the ostial cone, as shown in the preceding embodiments.
• Figs. 20-22 are schematic, pictorial illustrations showing successive stages in deployment of a system 100 for treatment of a vascular bifurcation, in accordance with an embodiment of the present invention.
• System 100 comprises a bifurcated balloon 112, which is designed to fit within a bifurcation of a main vessel 102 into branch vessels 104 and 106.
• branch vessel 104 may simply be a continuation of main vessel 102.
• guide wires 108 and 110 are inserted through vessel 102 into branch vessels 104 and 106, respectively.
• the operator then deploys system 100 in the area of the bifurcation site by advancing a catheter 116 over the guide wires.
• balloon 112 is contained inside a retainer, in the form of a securing sleeve 114, as shown in Fig. 20.
• the operator pulls the sleeve back in the proximal direction, as shown in Fig. 21, thus releasing a side chamber 120 of the balloon.
• the operator then advances the side chamber further into branch vessel 106 along guide wire 110, while advancing a main chamber 118 of the balloon into branch vessel 104 along guide wire 108.
• Balloon 112 may then be inflated, as shown in Fig. 22, thus treating both branch vessels 104 and 106 simultaneously.
• chambers 116 and 118 are shown in the figures as two parts of the same balloon, which are inflated and deflated simultaneously, the chambers may alternatively be configured as independently-inflatable parts. Further aspects of treating vascular bifurcations using bifurcated balloons (with or without a stent), which may also be carried out using system 100, are described in the above-mentioned PCT Patent Publication WO 2005/041810 A2.
• balloon 112 When treatment is completed, balloon 112 is deflated and is then withdrawn into sleeve 114 for removal from the patient's body.
• the use of sleeve 114 during insertion and/or removal of the balloon helps to ensure that the bifurcated balloon can be inserted and withdrawn easily from the area of the bifurcation, with minimal risk of damage to the balloon or to the blood vessels during this process.
• a spiral coil may be used as the retainer in place of sleeve 114.
• the spiral coil can be made from a superelastic shape- memory wire (such as NiTi wire), which can also be coated to serve as a radio-opaque marker.
• the spiral coil is wound so as to contain balloon 112 in roughly the same manner as sleeve 114.
• the operator pulls the wire in the proximal direction through a dedicated lumen in the catheter. The force of pulling straightens the wire, thus allowing easy retrieval.
• Fig. 23 is a schematic side view of a stent 130 for implantation in a vascular vessel
• the stent is shown here in a compact configuration, prior to deployment in a blood vessel.
• Stent 130 comprises a main section 132, having a suitable structure for expansion by a balloon.
• Struts 134 at the proximal end of the stent are used for anchoring the stent in the bifurcation.
• the struts are of gradated lengths to accord with the angle of the bifurcation, as shown in the figures that follow. Alternatively, the struts may all be of the same length. Figs.
• FIG. 24-27 are schematic, pictorial illustrations showing stages in a procedure for implanting stent 130 in the bifurcation of vessels 104 and 106, in accordance with still another embodiment of the present invention.
• a base stent 140 (shown in sectional view in these figures) has already been deployed in vessels 102 and 104.
• Stent 140 has a lateral opening 142, which is aligned with branch vessel 106.
• Methods for alignment of this sort are described in the above-mentioned PCT Patent Publication WO 2005/041810 A2.
• other methods for stent alignment that are known in the art may be used to ensure that lateral opening 142 is in the proper position when stent 140 is expanded into place.
• Stent 130 is crimped over a balloon 146, which comprises an inner part 148 and a collar 150, in similar fashion to the two-part balloons described above.
• Stent 130 and balloon 146 are advanced over a guide wire 144, which is threaded through opening 142 of stent 140 and into branch vessel 106.
• stent 130 is positioned so that inner part 140 protrudes through opening 142, while struts 134 and collar 150 of balloon 146 remain within stent 140, as shown in Fig. 25.
• Collar 150 is then inflated, as shown in Fig. 26, thus causing struts 134 to bend outward and engage stent 130 around opening 142.
• Bending struts 134 in this manner ensures that stent 130 is positioned properly in branch vessel 106.
• inner part 148 of balloon 146 is inflated, so that main part 132 of stent 130 expands outward to support vessel 106, as shown in Fig. 27.
• Bent struts 134 and inflated collar 150 hold stent 130 in the proper location during inflation and anchor stent 130 securely to stent 140, so that the two stents .function in. the bifurcation as though they were an integral unit.
• the dual-stent design shown in Figs. 24-27 is easier to manufacture and easier for the practitioner to implant properly than are bifurcated stents that are known in the art.
• stent 130 may first be introduced into branch vessel 106, and then deployed and anchored in place (including bending struts 134 outward using collar 150).
• base stent 140 is inserted and deployed in vessels 102 and 104, thereby engaging struts 134 and anchoring stent 130 in place.

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• 2006
  • 2006-02-07 AU AU2006213489A patent/AU2006213489A1/en not_active Abandoned
  • 2006-02-07 EP EP06711137A patent/EP1848272A2/en not_active Withdrawn
  • 2006-02-07 US US11/815,652 patent/US20080243233A1/en not_active Abandoned
  • 2006-02-07 WO PCT/IL2006/000147 patent/WO2006085304A2/en not_active Ceased
  • 2006-02-07 KR KR1020077020535A patent/KR20070116813A/ko not_active Withdrawn
  • 2006-02-07 JP JP2007554732A patent/JP2008532577A/ja not_active Withdrawn
  • 2006-02-07 MX MX2007009589A patent/MX2007009589A/es not_active Application Discontinuation
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