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
  • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
  • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
• • 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
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
  • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
  • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
• • 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
  • A61F2/02—Prostheses implantable into the body
  • A61F2/04—Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts
  • A61F2/06—Blood vessels
  • A61F2002/065—Y-shaped blood vessels
• • 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
  • A61F2002/826—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents more than one stent being applied sequentially
• • 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
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
  • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
  • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
  • A61F2002/91508—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other the meander having a difference in amplitude along the band
• • 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
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
  • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
  • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
  • A61F2002/91516—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other the meander having a change in frequency along the band
• • 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
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
  • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
  • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
  • A61F2002/91525—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• • 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
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
  • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
  • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
  • A61F2002/91533—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other characterised by the phase between adjacent bands
• • 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
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
  • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes
  • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheets or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
  • A61F2002/9155—Adjacent bands being connected to each other
  • A61F2002/91575—Adjacent bands being connected to each other connected peak to trough
• • 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
  • A61F2230/00—Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2230/0002—Two-dimensional shapes, e.g. cross-sections
  • A61F2230/0028—Shapes in the form of latin or greek characters
  • A61F2230/0054—V-shaped
• • 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
  • A61F2250/0018—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 elasticity, stiffness or compressibility
• • 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
  • A61F2250/0029—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 bending or flexure capacity
• • 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

Definitions

• the present invention generally relates to intravascular stents and more particularly, pertains to specialized stent configurations for the treatment of vascular disease within non-uniform vessels such as, for example, a tapered artery, or at the ostium or bifurcation of an artery.
• Stents or expandable grafts are implanted in a variety of body lumens in an effort to maintain their patency.
• These devices typically are intraluminally implanted by use of a catheter which is inserted at an easily accessible location and then advanced to the deployment site.
• the stent initially is maintained in a radially compressed or collapsed state to enable it to be maneuvered through the lumen. Once in position, the stent is deployed which, depending upon its construction, is achieved either automatically by, for example, removing a restraint, or actively by, for example, the inflation of a balloon about which the stent is carried on the catheter.
• Intravascular stents currently in use typically are designed to expand or to be expanded within a diseased vessel to a given nominal diameter that is constant along the entire length of the stent.
• the stent also typically is uniform along its entire length in terms of its radial strength, its longitudinal flexibility and its coverage, i.e., the actual area of stent material defining the surface of the deployed stent relative to the area of vessel covered thereby.
• Most blood vessels are not of constant diameter, exhibiting either a natural taper or a narrowing, particularly near bifurcations. Blood vessels may be abruptly tapered over short lengths (less than 20mm), as in the carotid arteries, or gradually tapered over long lengths (greater than 20mm), as in the iliac arteries.
• bifurcation sites in the human circulatory system include the vascular profile where the external and internal carotid arteries branch out from the common carotid artery.
• the common carotid artery is 7-9 mm in diameter while the internal carotid artery is 4-6 mm in diameter.
• a stent deployed therein must accommodate a 3-5 mm diameter change over a length of about 20-30 mm.
• Another example involves the stenting of the renal arteries. In order to cover the entire ostial area, it is necessary for the stent to conform to the interior of the renal artery and to flare into the significantly larger aorta.
• the lesions present at the ostium are typically hard and calcified requiring the stent to possess greater strength in that specific region. Similar requirements arise in the treatment of ostial disease at the bifurcation in native coronary arteries or bypass grafts and aorta-ostial disease in the peripheral (e.g., carotid, renal and iliac) arteries. Non-uniformities also may be present by virtue of a curved or tortuous configuration of the blood vessel at the diseased site.
• a stent therefore is needed with which a non-uniform vessel may be uniformly supported to provide consistency in terms of coverage, radial strength, and longitudinal flexibility along its entire length.
• a stent is needed that is capable of providing specific variations in terms of coverage, radial strength, and longitudinal flexibility at certain locations along its length, in order to accommodate varying needs along the length of a particular vessel.
• a stent of the present invention may be constructed so as to provide uniform coverage, uniform radial strength and/or uniform longitudinal flexibility to a non- uniformly shaped deployment site such as a vessel that is tapered or bifurcated.
• a non- uniformly shaped deployment site such as a vessel that is tapered or bifurcated.
• such stent may be constructed to accommodate non-uniform requirements of a particular site, wherein specific variations in flexibility, radial strength or coverage are required at specific locations along such stent.
• the desired functional differentiation is achieved with a stent that is structurally differentiated in a preselected manner. Dimensional or geometric differentiation, or both dimensional and geometric differentiation, are relied upon to impart the desired variations of functional characteristics to a particular stent.
• Such structural differentiation may be gradual or abrupt and may include several different type of differentiations along the length of the stent.
• a stent of the present invention constructed for deployment in a tapered vessel has a gradually increasing expansion ratio along is length. Such differentiation may be achieved with an assembly of axially aligned rings each with a serpentine structure, wherein each repeating pattern of serpentines defines a single unit cell. By selecting the size of the unit cells in successive rings to be increasingly wider, an increased amount of material becomes available for expansion. Upon expansion, such stent assumes the tapered shape of a truncated cone to match the shape of the tapered artery. Despite its tapered shape, the stent nonetheless provides uniform coverage of the walls of the tapered vessel as well as exhibits uniform radial strength and longitudinal flexibility along its entire length.
• the stent may be alternatively constructed so as to expand into any of a variety of shapes or profiles to fit a particular application. Geometric or dimensional as well as both geometric and dimensional variations of the unit cell may be employed to achieve such functional variation.
• a stent of the present invention may be non- uniformly constructed so as to attain a uniform diameter along its entire length while it exhibits preselected variations of coverage, radial strength, or longitudinal flexibility along its length.
• This is achievable by, for example, varying the thickness of the serpentine elements while the width of each serpentine element is held constant, or by varying the number of unit cells in certain serpentine elements.
• a similar result can be achieved by simultaneously varying the dimensions (i.e., strut width and/or thickness of the unit cell), or the geometry, or both the dimensions and the geometry of the individual unit cells.
• FIGURE 1 is a greatly enlarged plan view of a longitudinally severed and flattened stent of the present invention, shown in the predeployed state.
• FIG. 2 is a perspective view of the stent shown in FIG. 1, also in the predeployed state.
• FIG. 3 is a greatly enlarged plan view of the longitudinally severed and flattened stent of FIG. 1, shown in the deployed state.
• FIG. 4 is a perspective view of the stent shown in FIG. 3, also in the deployed state.
• Stents of the present invention are specifically constructed for particular deployment sites and thereby overcome the shortcomings inherent in attempting to fit a uniform stent to a non-uniform site.
• the non-uniformity of the site may include a taper, a bifurcation, an ostium, or any other variation in terms of dimensions or support requirements.
• the stent is maneuvered into place in the conventional manner, such as by a catheter about which it is carried while in its collapsed state. Once in position, the stent is expanded such as by the inflation of one or more balloons, or in the case of self expanding stents, a confining sheath is removed to allow the stent to expand automatically.
• the stent By providing a tapered stent for deployment within a tapered artery, uniform coverage, uniform radial strength and uniform stiffness nonetheless may be achieved along the entire length of the stent.
• the versatility of the system of the present invention allows a non-uniform stent to be constructed that imparts enhanced coverage, strength or stiffness at preselected locations so as to, for example, provide the needed support requirements in a diseased ostium.
• FIG. l illustrates stent 12 incorporating features of the present invention and more specifically, a stent for deployment in a tapered artery.
• the stent typically is tubular in its overall shape, however, the drawing shows the stent in a longitudinally severed and flattened state in order to clearly display its structure.
• the stent structure generally consists of a series of circumferentially extending serpentine elements (14, 16, ...30) that are interconnected by links 32 extending between adjacent se ⁇ entine elements.
• Each of the se ⁇ entine elements may be characterized as being made up of a number of individual unit cells 34, wherein each such cell consists of link 32 attached to two adjacent U- or V-shaped ribs 36,38.
• each se ⁇ entine element Adjacent se ⁇ entine elements are arranged such that the respective series of apexes are in phase, and in longitudinal alignment with one another. All links extend from the same side of the se ⁇ entine elements. In the embodiment illustrated, all links extend between the left edges of the individual se ⁇ entine element.
• each se ⁇ entine element is differentiated relative to the adjacent se ⁇ entine elements in terms of the width of the se ⁇ entine pattern, i.e., the length of each rib element as well as of each link element.
• each successive se ⁇ entine element is progressively wider than the previous element, consequently, the rib and link elements of the respective unit cells are longer.
• the number of unit cells in each se ⁇ entine element remains unchanged, as does the thickness and width of all of the rib and spine elements.
• FIG. 2 is a perspective view of stent 12 as it actually appears in use prior to deployment.
• the overall tubular structure is of uniform diameter and each of the se ⁇ entine elements extend about the entire circumference of the device.
• the individual se ⁇ entine elements are recognizable as rings while the individual links 32 extend only between adjacent rings.
• the diameter of the stent is selected to be sufficiently small to allow passage through a patient's vasculature to the deployment site.
• FIG. 3 illustrates the stent shown in FIGS. 1 and 2 in its deployed state. The device again is shown longitudinally severed and flattened in order to more clearly display its structure.
• the expansion of the device results in a tapered shape wherein the wider se ⁇ entine elements shown towards the right side of the device expand to a greater extent than the narrower se ⁇ entine elements shown toward the left side of the device.
• Such expansion results in a truncated cone shape when shown in perspective as in FIG. 4.
• Each of U- or V-shaped ribs 36,38 assumes a wider, more open angle while the links 32 remain essentially stationary and aligned. The deformation and expansion of the ribs provides for the increase in the diameter of the device, yet the overall length of the stent remains essentially unchanged during deployment of the stent, since the links connect only adjacent rings to each other.
• any shortening would not only reduce the total area supported by the device, but also could cause trauma to the surrounding tissue during deployment. Additionally, because more stent material is present in the larger diameter rings by virtue of the presence of the same number of longer ribs, the radial strength, coverage and stiffness of the stent remains fairly constant along its entire length.
• the above-described variables can be selected such that the resulting stent is specifically tailored to a very specific anatomical requirement, be it the taper, bifurcation twist, or ostium of a vessel.
• the same variables can be selected such that the resulting stent is specifically tailored to provide a desired radial strength, longitudinal flexibility, or coverage differentiation.
• a stent of the present invention may be constructed using any number of well-known techniques.
• a stainless steel tube is laser cut with the desired stent pattern as is known in the art.
• Digital angiography and advanced computing algorithms are valuable tools that are readily useable to create a structurally differentiated stent that conforms to the natural profile of a vessel upon deployment.
• Chemical etching or electro-polishing techniques which are well known, subsequently may be used to selectively vary the wall thickness of such stent.
• Deployment maybe achieved by shaped balloons for balloon-expandable stents whereby a tapered balloon is used to expand a tapered stent within a tapered vessel.
• multiple balloons of varying size may be used to achieve a similar effect, as may the tapered section of an over-sized balloon.
• the stent may be constructed to be self-expanding by any of various techniques well known in the art. Deployment of a self-expanding stent can be achieved by subjecting the collapsed stent which is constructed of a shape memory alloy, to certain temperatures which cause it to expand. A stent constructed of elastic material may be forcefully collapsed and constrained within a sheath. Removal of the sheath allows the stent to automatically expand.
• Balloon expandable stents may be manufactured from any number of ductile metals and alloys including, stainless steel, tantalum, and platinum-iridium alloys, either coated or uncoated.
• Self-expanding stents are constructed of shape memory or superelastic materials or alloys such as NiTi alloys, including Nitinol, and Cu-Zn alloys.

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• 1999
  • 1999-11-09 EP EP99972088A patent/EP1047357A1/de not_active Withdrawn
  • 1999-11-09 JP JP2000581972A patent/JP3626097B2/ja not_active Expired - Lifetime
  • 1999-11-09 AU AU14728/00A patent/AU1472800A/en not_active Abandoned
  • 1999-11-09 CA CA002312566A patent/CA2312566A1/en not_active Abandoned
  • 1999-11-09 CN CN99802014A patent/CN1287478A/zh active Pending
  • 1999-11-09 WO PCT/US1999/026423 patent/WO2000028922A1/en not_active Application Discontinuation

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