WO2001043810A1 - Stent - Google Patents

Stent Download PDF

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Publication number
WO2001043810A1
WO2001043810A1 PCT/AU2000/001552 AU0001552W WO0143810A1 WO 2001043810 A1 WO2001043810 A1 WO 2001043810A1 AU 0001552 W AU0001552 W AU 0001552W WO 0143810 A1 WO0143810 A1 WO 0143810A1
Authority
WO
WIPO (PCT)
Prior art keywords
stent
tube
tube according
links
adjacent
Prior art date
Application number
PCT/AU2000/001552
Other languages
French (fr)
Inventor
Andrew Thomson
Original Assignee
Firefly Technologies Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Firefly Technologies Pty Ltd filed Critical Firefly Technologies Pty Ltd
Priority to AU23283/01A priority Critical patent/AU2328301A/en
Publication of WO2001043810A1 publication Critical patent/WO2001043810A1/en

Links

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 sheet material 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 sheet material 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
    • A61F2/82—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 sheet material 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
    • A61F2/95—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
    • A61F2/82—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 sheet material 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 sheet material 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 sheet material 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
    • A61F2002/91541—Adjacent bands are arranged out of phase
    • 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 sheet material 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 sheet material 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
    • A61F2002/91558—Adjacent bands being connected to each other connected peak to peak
    • 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

Definitions

  • the present invention relates to stents for treating stenoses and methods associated therewith.
  • a stent for placement in an artery is mounted on a balloon which is significantly longer than the stent.
  • the balloon is inflated to high pressure (currently thought to be the best method) there is a risk that the non-stenosed artery at either end of the stent could be damaged.
  • a balloon is 20 mm in length and a 15 mm stent is mounted on this balloon then when the balloon is inflated to high pressure there is a segment of artery subjected to substantial barotrauma. This barotrauma is associated with in increased risk of restenosis.
  • the alternative strategy of using a 2 stage stent insertion using low pressure balloon inflation and subsequent high pressure inflation with a shorter balloon does not necessarily overcome this problem.
  • a tube for forming a balloon expandable stent of desired length comprising two or more discrete stent sections, each stent section being connected to an adjacent stent section by a severable link to allow the tube to be cut to the desired length, wherein each stent section is radially expandable substantially without shortening.
  • the tube of the present invention enables a stent of desired length to be produced specifically to suit the lesion to be treated (stent length may be chosen based on stenosis length).
  • the stent may be crafted to the desired length by suitably cutting one or more of the severable links.
  • the tube of the present invention enables this stent length to be substantially maintained during expansion of the stent.
  • the tube is configured to provide access to the links to enable the links to be readily manually severed.
  • a surgeon may manually cut the tube to produce a stent of desired length without undue risk of damaging the stent structure in the vicinity of the link or links intended to be severed.
  • the distance between the ends of an element of the at least one stent section may be considerably longer than the longitudinal distance between the ends of a connecting member of the at least one stent section.
  • the tube is constructed such that at least one connecting member is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in the longitudinal direction.
  • the connecting member may be arranged to alternate direction back and forth as described in any suitable arrangement.
  • the at least one connecting member is formed by a substantially sinusoidal strip. One or more of the substantially sinusoidal strips may have one period of the sinusoid.
  • the tube may be constructed so that at least one of the links is longitudinally extendable. Such a tube may be constructed so that longitudinal shortening of bands causes longitudinal extension of the at least one of the links.
  • the tube may be constructed so that longitudinally successive links are circumferentially spaced apart relative to one another. Preferably, successive links are spaced progressively in the circumferential direction. This arrangement provides the stent with longitudinal strength, and with flexibility.
  • Stent sections of the tube may be connected to adjacent stent sections by one severable link. They may be connected by two severable links. They may be connected by three severable links.
  • a stent formed from a tube according to the invention.
  • a method for forming a stent of desired length from a tube comprising two or more discrete stent sections, each stent section being connected to an adjacent stent section by a severable link to allow the tube to be cut to the desired length, the method comprising cutting at least one link to form a stent of desired length.
  • a method for forming a stent of desired length from a tube comprising cutting at least one link to form a stent of desired length.
  • the method may comprise cutting the at least one link with a scalpel.
  • a stent formed according to a method of the present invention there is provided a stent formed according to a method of the present invention.
  • a method for treating a stenosed body lumen comprising positioning a stent in the stenosis, the stent being in accordance with the present invention.
  • Figure 1 is a side elevational view of one embodiment of a tube according to the present invention.
  • Figure 2 is side elevational view of a stent formed from a tube according to Figure 1 before "crimping' onto an angioplasty balloon;
  • Figure 3 is a side elevational view of the stent of Figure 2 after balloon expansion;
  • Figure 4 is a plan view of the structure of a further embodiment for formation of a tube according to the present invention.
  • Figure 5 is a plan view of an embodiment of a stent section according to the present invention.
  • Figure 1 shows a tube 10 according to the present invention.
  • Tube 10 is approximately cylindrical. It comprises numerous discrete stent sections 20.
  • the stent sections 20 are connected to adjacent stent sections by substantially sinusoidal severable links 30, 31, 32, 33, 34, 35 and 36.
  • the longitudinally successive links are circumferentially spaced apart relative to one another, each successive link also being spaced progressively in the circumferential direction.
  • link 31 is circumferentially spaced apart from link 30 by a given distance
  • link 32 is circumferentially spaced apart from link 31 by the same given distance etc. This progressive arrangement provides the stent with longitudinal strength, and with flexibility.
  • each stent section 20 comprises five longitudinally adjacent substantially annular bands 40. 41, 42, 43 and 44.
  • Each annular band is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in the circumferential direction by being formed from a plurality of substantially straight elements 50 connected to each other to form a substantially zigzagging strip.
  • the bands 40, 41 , 42, 43 and 44 are thus circumferentially extendable.
  • Figure 3 shows the stent section 20 of figure 2 after bands 40, 41 , 42, 43 and 44 have undergone circumferential extension (due to radial expansion of the stent section). Due to the increased angles between connected straight elements 50 (compare figures 1 and 2), the longitudinal length of bands 40, 41 , 42, 43 and 44 is shortened by the radial expansion of the stent section.
  • Each stent section 20 also comprises a plurality of connecting members 60 that define a path that alternates direction back and forth as the strip proceeds in the longitudinal direction by being formed by a substantially sinusoidal strip (representing one period of the sinusoid).
  • the connecting members 60 are thus longitudinally extendable.
  • connecting members 60 undergo longitudinal extension (by being pulled in opposite directions by longitudinally adjacent bands).
  • the longitudinal shortening of the bands 40, 41, 42, 43 and 44 is substantially compensated for by the longitudinal extension of the connecting members 60, so that the stent section 20 is radially expandable substantially without shortening.
  • Stent section 20 is constructed such that the distance between the ends of substantially straight elements 50 is considerably longer than the longitudinal distance between the ends of connecting members 60.
  • the stent a portion of which is shown in Figure 2, is designed to be "hand mounted' and 'crimped' onto an angioplasty balloon. (The process of hand mounting and crimping involves the placement of the stent around the angioplasty balloon and then squeezing the stent manually onto the balloon.) During this process, the stent is designed to increase the curvature (i.e. decreasing the period or wavelength) of the sinusoidal connecting members 60 and links 30, 31 , 32, 33, 34, 35 and 36 thereby allowing the stent to reduce its radial dimensions again without substantial change in overall longitudinal dimensions.
  • This change in the sinusoidal shaped parts of the stent allows the stent to reduce its diameter and become 'fixed' or 'mounted " on a balloon catheter by radial compression thereby ensuring that the stent does not become dislodged from the balloon during passage of the balloon and stent through the vasculature to the desired position in the vessel.
  • Figure 4 shows a structure which can be configured into an approximately cylindrical tube for forming a stent.
  • the tube comprises numerous discrete stent sections 20.
  • the stent sections 20 are connected to adjacent stent sections by substantially straight severable links 300, 310, and 320.
  • the longitudinally successive links are circumferentially spaced apart relative to one another, each successive link also being spaced progressively in the circumferential direction.
  • link 310 is circumferentially spaced apart from link 300 by a given distance
  • link 320 is circumferentially spaced apart from link 310 by the same given distance etc.
  • This progressive arrangement provides the stent with longitudinal strength.
  • Each stent section 20 also comprises a plurality of bands 70.
  • Each band 70 is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in a circumferential direction.
  • Each stent section 20 also comprises a plurality of substantially sinusoidal shaped connecting members 80 to connect adjacent bands and define a path that alternates direction back and forth as the strip proceeds in the longitudinal direction by being formed by a substantially sinusoidal strip (representing one period of the sinusoid).
  • the connecting members 80 are thus longitudinally extendable.
  • the connecting members 80 After the bands 70 have undergone circumferential extension (due to radial expansion of the stent section 20), due to the straightening of the connecting members 80 the distance between adjacent bands is reduced by the radial expansion of the stent section 20. Since the connecting members 80 define a path that alternates direction back and forth as the strip proceeds in the longitudinal direction, the connecting members 80 are thus longitudinally extendable.
  • connecting members 80 When the stent section 20 is radially expanded, the distance between adjacent bands is initially shortened. This shortening causes connecting members 80 to subsequently undergo longitudinal extension (by being pulled in opposite directions by adjacent bands).
  • the shortening of the distance between adjacent bands 70 is substantially compensated for by the subsequent longitudinal extension of the connecting members 80, so that the stent section 20 is radially expandable substantially without shortening.
  • the stent. is designed to be 'hand mounted " and 'crimped" onto an angioplasty balloon. (The process of hand mounting and crimping involves the placement of the stent around the angioplasty balloon and then squeezing the stent manually onto the balloon.) During this process, the stent is designed to increase the curvature (i.e. decreasing the period or wavelength) of connecting members 80 thereby allowing the stent to reduce its radial dimensions again without substantial change in overall longitudinal dimensions.
  • This change in the sinusoidal shaped parts of the stent allows the stent to reduce its diameter and become 'fixed * or 'mounted' on a balloon catheter by radial compression thereby ensuring that the stent does not become dislodged from the balloon during passage of the balloon and stent through the vasculature to the desired position in the vessel.
  • the tube is made of malleable material, such as stainless steel, tungsten or platinum. Such materials are sufficiently deformable to allow expansion of the stent under outward radial pressure applied by standard balloon angioplasty catheters. These materials are also generally of sufficient strength and stiffness to allow the stent to maintain the luminal diameter of the vessel into which it is inserted.
  • a surgeon may sever one or more links of the tube 10 to produce a stent of desired length.
  • the tube provides space around the links, thus providing access to the links to enable a link to be readily manually severed.
  • a surgeon may manually cut a link of the tube without undue risk of damaging the stent structure in the vicinity of the link or links intended to be severed.
  • a scalpel may be introduced into the slot between adjacent stent sections without undue risk of damaging the stent structure.

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  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Optics & Photonics (AREA)
  • Cardiology (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Transplantation (AREA)
  • Physics & Mathematics (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Media Introduction/Drainage Providing Device (AREA)

Abstract

The present invention provides a tube (10) for forming a balloon expandable stent of desired length, the tube comprising two or more discrete stent sections (20), each stent section (20) being connected to an adjacent stent section (20) by a severable link (30, 31, 32, 33, 34, 35, 36) to allow the tube (10) to be cut to the desired length, wherein each stent section (20) is radially expandable substantially without shortening. There is also provided a method for forming a stent of desired length from a tube (10) by cutting at least one link (30, 31, 32, 33, 34, 35, 36) to form a stent of desired length. There is also provided a method for treating a stenosed body lumen by positioning a stent according to the present invention in the stenosis.

Description

Stent
Field of the invention
The present invention relates to stents for treating stenoses and methods associated therewith.
Background of the invention
In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date: (i) part of common general knowledge: or
(ii) known to be relevant to an attempt to solve any problem with which this specification is concerned.
Prior art stents generally come in standard sizes, which might not be appropriate for the treatment of particular stenoses. In this regard, it appears that the length of many stents is chosen to fit on a 20 mm balloon. This balloon size seems to be a traditional length without scientific evidence for being ideal.
Further, if a stent for placement in an artery is mounted on a balloon which is significantly longer than the stent. if the balloon is inflated to high pressure (currently thought to be the best method) there is a risk that the non-stenosed artery at either end of the stent could be damaged. For example, if a balloon is 20 mm in length and a 15 mm stent is mounted on this balloon then when the balloon is inflated to high pressure there is a segment of artery subjected to substantial barotrauma. This barotrauma is associated with in increased risk of restenosis. The alternative strategy of using a 2 stage stent insertion using low pressure balloon inflation and subsequent high pressure inflation with a shorter balloon does not necessarily overcome this problem.
Thus there would be advantage in finding a means for having greater control over the length of a balloon expandable stent. both for matching a stent and balloon, and in choosing an appropriate stent for the stenosis in question. Summary of the invention
According to an aspect of the present invention, there is provided a tube for forming a balloon expandable stent of desired length, the tube comprising two or more discrete stent sections, each stent section being connected to an adjacent stent section by a severable link to allow the tube to be cut to the desired length, wherein each stent section is radially expandable substantially without shortening.
The tube of the present invention enables a stent of desired length to be produced specifically to suit the lesion to be treated (stent length may be chosen based on stenosis length). The stent may be crafted to the desired length by suitably cutting one or more of the severable links. The tube of the present invention enables this stent length to be substantially maintained during expansion of the stent.
Preferably, the tube is configured to provide access to the links to enable the links to be readily manually severed. Thus, a surgeon may manually cut the tube to produce a stent of desired length without undue risk of damaging the stent structure in the vicinity of the link or links intended to be severed.
The tube may be provided wherein at least one stent section comprises at least two longitudinally adjacent substantially annular bands, each band being circumferentially extendable, each longitudinally adjacent pair of bands being connected together by a plurality of connecting members, the connecting members being longitudinally extendable. the bands and connecting members being so configured that radial expansion of the stent causes:
(a) circumferential extension and longitudinal shortening of each band; and
(b) longitudinal extension of the connecting members, wherein the longitudinal shortening of the bands is substantially compensated for by the longitudinal extension of the connecting members, whereby the stent section is radially expandable substantially without shortening.
A band of the at least one stent section may be formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in the circumferential direction. By having the strip define such a path, the strip is thereby made extendable in the circumferential direction. The band of the at least one stent section may be arranged to alternate direction back and forth as described in any suitable arrangement. In one arrangement, the band of the at least one stent section may be formed from a plurality of substantially straight elements connected to each other to form a substantially zig-zagging strip. In another arrangement, the band of the at least one stent section may be formed by a strip comprising a plurality of adjacent substantially parallel elements, each element being connected to an adjacent element by a curved connecting member. The distance between the ends of an element of the at least one stent section may be considerably longer than the longitudinal distance between the ends of a connecting member of the at least one stent section. Preferably the tube is constructed such that at least one connecting member is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in the longitudinal direction. The connecting member may be arranged to alternate direction back and forth as described in any suitable arrangement. In one arrangement, the at least one connecting member is formed by a substantially sinusoidal strip. One or more of the substantially sinusoidal strips may have one period of the sinusoid.
The tube may be constructed so that at least one of the links is longitudinally extendable. Such a tube may be constructed so that longitudinal shortening of bands causes longitudinal extension of the at least one of the links. The tube may be constructed so that longitudinally successive links are circumferentially spaced apart relative to one another. Preferably, successive links are spaced progressively in the circumferential direction. This arrangement provides the stent with longitudinal strength, and with flexibility.
Stent sections of the tube may be connected to adjacent stent sections by one severable link. They may be connected by two severable links. They may be connected by three severable links.
According to another aspect of the present invention, there is provided a stent formed from a tube according to the invention.
According to a further aspect of the present invention, there is provided a method for forming a stent of desired length from a tube, the tube comprising two or more discrete stent sections, each stent section being connected to an adjacent stent section by a severable link to allow the tube to be cut to the desired length, the method comprising cutting at least one link to form a stent of desired length.
According to a yet further aspect of the present invention, there is provided a method for forming a stent of desired length from a tube, the tube being as described above, the method comprising cutting at least one link to form a stent of desired length. The method may comprise cutting the at least one link with a scalpel.
According to another aspect of the present invention, there is provided a stent formed according to a method of the present invention.
According to a another aspect of the present invention, there is provided a method for treating a stenosed body lumen, the method comprising positioning a stent in the stenosis, the stent being in accordance with the present invention.
Description of the drawings
The invention will now be further explained and illustrated by reference to the accompanying drawings in which: Figure 1 is a side elevational view of one embodiment of a tube according to the present invention;
Figure 2 is side elevational view of a stent formed from a tube according to Figure 1 before "crimping' onto an angioplasty balloon;
Figure 3 is a side elevational view of the stent of Figure 2 after balloon expansion; Figure 4 is a plan view of the structure of a further embodiment for formation of a tube according to the present invention, and
Figure 5 is a plan view of an embodiment of a stent section according to the present invention.
Figure 1 shows a tube 10 according to the present invention. Tube 10 is approximately cylindrical. It comprises numerous discrete stent sections 20. The stent sections 20 are connected to adjacent stent sections by substantially sinusoidal severable links 30, 31, 32, 33, 34, 35 and 36. The longitudinally successive links are circumferentially spaced apart relative to one another, each successive link also being spaced progressively in the circumferential direction. For example, link 31 is circumferentially spaced apart from link 30 by a given distance, link 32 is circumferentially spaced apart from link 31 by the same given distance etc. This progressive arrangement provides the stent with longitudinal strength, and with flexibility.
As is most clearly seen in Figure 2. each stent section 20 comprises five longitudinally adjacent substantially annular bands 40. 41, 42, 43 and 44. Each annular band is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in the circumferential direction by being formed from a plurality of substantially straight elements 50 connected to each other to form a substantially zigzagging strip. The bands 40, 41 , 42, 43 and 44 are thus circumferentially extendable.
Figure 3 shows the stent section 20 of figure 2 after bands 40, 41 , 42, 43 and 44 have undergone circumferential extension (due to radial expansion of the stent section). Due to the increased angles between connected straight elements 50 (compare figures 1 and 2), the longitudinal length of bands 40, 41 , 42, 43 and 44 is shortened by the radial expansion of the stent section.
Each stent section 20 also comprises a plurality of connecting members 60 that define a path that alternates direction back and forth as the strip proceeds in the longitudinal direction by being formed by a substantially sinusoidal strip (representing one period of the sinusoid). The connecting members 60 are thus longitudinally extendable.
When the stent section 20 is radially expanded, the longitudinal length of bands 40,
41, 42. 43 and 44 is shortened, as explained above. In other words, the distance between adjacent bands is reduced. This shortening causes connecting members 60 to undergo longitudinal extension (by being pulled in opposite directions by longitudinally adjacent bands).
As can be seen by comparing Figures 2 and 3, the longitudinal shortening of the bands 40, 41, 42, 43 and 44 is substantially compensated for by the longitudinal extension of the connecting members 60, so that the stent section 20 is radially expandable substantially without shortening.
Stent section 20 is constructed such that the distance between the ends of substantially straight elements 50 is considerably longer than the longitudinal distance between the ends of connecting members 60. The stent, a portion of which is shown in Figure 2, is designed to be "hand mounted' and 'crimped' onto an angioplasty balloon. (The process of hand mounting and crimping involves the placement of the stent around the angioplasty balloon and then squeezing the stent manually onto the balloon.) During this process, the stent is designed to increase the curvature (i.e. decreasing the period or wavelength) of the sinusoidal connecting members 60 and links 30, 31 , 32, 33, 34, 35 and 36 thereby allowing the stent to reduce its radial dimensions again without substantial change in overall longitudinal dimensions. This change in the sinusoidal shaped parts of the stent allows the stent to reduce its diameter and become 'fixed' or 'mounted" on a balloon catheter by radial compression thereby ensuring that the stent does not become dislodged from the balloon during passage of the balloon and stent through the vasculature to the desired position in the vessel.
Figure 4 shows a structure which can be configured into an approximately cylindrical tube for forming a stent. When formed the tube comprises numerous discrete stent sections 20. The stent sections 20 are connected to adjacent stent sections by substantially straight severable links 300, 310, and 320. The longitudinally successive links are circumferentially spaced apart relative to one another, each successive link also being spaced progressively in the circumferential direction. For example, link 310 is circumferentially spaced apart from link 300 by a given distance, link 320 is circumferentially spaced apart from link 310 by the same given distance etc. This progressive arrangement provides the stent with longitudinal strength. Each stent section 20 also comprises a plurality of bands 70. Each band 70 is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in a circumferential direction.
Each stent section 20 also comprises a plurality of substantially sinusoidal shaped connecting members 80 to connect adjacent bands and define a path that alternates direction back and forth as the strip proceeds in the longitudinal direction by being formed by a substantially sinusoidal strip (representing one period of the sinusoid). The connecting members 80 are thus longitudinally extendable.
After the bands 70 have undergone circumferential extension (due to radial expansion of the stent section 20), due to the straightening of the connecting members 80 the distance between adjacent bands is reduced by the radial expansion of the stent section 20. Since the connecting members 80 define a path that alternates direction back and forth as the strip proceeds in the longitudinal direction, the connecting members 80 are thus longitudinally extendable.
When the stent section 20 is radially expanded, the distance between adjacent bands is initially shortened. This shortening causes connecting members 80 to subsequently undergo longitudinal extension (by being pulled in opposite directions by adjacent bands).
In this preferred embodiment, the shortening of the distance between adjacent bands 70 is substantially compensated for by the subsequent longitudinal extension of the connecting members 80, so that the stent section 20 is radially expandable substantially without shortening.
The stent. is designed to be 'hand mounted" and 'crimped" onto an angioplasty balloon. (The process of hand mounting and crimping involves the placement of the stent around the angioplasty balloon and then squeezing the stent manually onto the balloon.) During this process, the stent is designed to increase the curvature (i.e. decreasing the period or wavelength) of connecting members 80 thereby allowing the stent to reduce its radial dimensions again without substantial change in overall longitudinal dimensions. This change in the sinusoidal shaped parts of the stent allows the stent to reduce its diameter and become 'fixed* or 'mounted' on a balloon catheter by radial compression thereby ensuring that the stent does not become dislodged from the balloon during passage of the balloon and stent through the vasculature to the desired position in the vessel.
The tube is made of malleable material, such as stainless steel, tungsten or platinum. Such materials are sufficiently deformable to allow expansion of the stent under outward radial pressure applied by standard balloon angioplasty catheters. These materials are also generally of sufficient strength and stiffness to allow the stent to maintain the luminal diameter of the vessel into which it is inserted.
The absence of links at the same circumferential positions between adjacent stent sections does not substantially reduce the overall radial strength of the stent, yet provides it with substantial flexibility to accommodate natural flexion, such as that of coronary arteries during cardiac contraction. In use, a surgeon may sever one or more links of the tube 10 to produce a stent of desired length. The tube provides space around the links, thus providing access to the links to enable a link to be readily manually severed. Thus, a surgeon may manually cut a link of the tube without undue risk of damaging the stent structure in the vicinity of the link or links intended to be severed. In particular, a scalpel may be introduced into the slot between adjacent stent sections without undue risk of damaging the stent structure.
The word 'comprising' and forms of the word 'comprising' as used in this description and in the claims does not limit the invention claimed to exclude any variants or additions. Modifications and improvements to the invention will be readily apparent to those skilled in the art. Such modifications and improvements are intended to be within the scope of this invention.

Claims

CLAIMS:
1. A tube for forming a balloon expandable stent of desired length, the tube comprising two or more discrete stent sections, each stent section being connected to an adjacent stent section by a severable link to allow the tube to be cut to the desired length, wherein each stent section is radially expandable substantially without shortening.
2. A tube according to claim 1 configured to provide access to the links to enable the links to be readily manually severed.
3. A tube according to claim 1 or claim 2 wherein at least one stent section comprises at least two longitudinally adjacent substantially annular bands, each band being circumferentially extendable, each longitudinally adjacent pair of bands being connected together by a plurality of connecting members, the connecting members being longitudinally extendable, the bands and connecting members being so configured that radial expansion of the stent causes: (a) circumferential extension and longitudinal shortening of each band; and
(b) longitudinal extension of the connecting members, wherein the longitudinal shortening of the bands is substantially compensated for by the longitudinal extension of the connecting members, whereby the stent section is radially expandable substantially without shortening.
4. A tube according to claim 3 wherein a band of the at least one stent section is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in the circumferential direction.
5. A tube according to claim 4 wherein the band of the at least one stent section is formed from a plurality of substantially straight elements connected to each other to form a substantially zig-zagging strip.
6. A tube according to claim 4 wherein the band is formed by a strip comprising a plurality of adjacent substantially parallel elements, each element being connected to an adjacent element by a curved connecting member.
7. A tube according to claim 5 or claim 6 wherein the distance between the ends of an element of the at least one stent section-is considerably longer than the longitudinal distance between the ends of a connecting member of the at least one stent section.
8. A tube according to any one of the preceding claims wherein at least one connecting member is formed by a strip that defines a path that alternates direction back and forth as the strip proceeds in the longitudinal direction.
9. A tube according to claim 8 wherein the at least one connecting member is formed by a substantially sinusoidal strip.
10. A tube according to claim 9 wherein one or more of the substantially sinusoidal strips have one period of the sinusoid.
1 1. A tube according to any one of claims 1 to 10 wherein at least one of the links is longitudinally extendable.
12. A tube according to claim 11 wherein the at least one of the links is longitudinally extendable and longitudinal shortening of bands causes longitudinal extension of the at least one of the links.
13. A tube according to any one of the preceding claims wherein longitudinally successive links are circumferentially spaced apart relative to one another.
14. A tube according to claim 13 wherein successive links are spaced progressively in the circumferential direction.
15. A tube according to any one of the preceding claims wherein stent sections are connected to adjacent stent sections by one severable link.
16. A tube according to any one of claims 1 to 14 wherein stent sections are connected to adjacent stent sections by two severable links.
17. A tube according to any one of claims 1 to 14 wherein stent sections are connected to adjacent stent sections by three severable links.
18. A stent formed from a tube according to any one of the preceding claims.
19. A method for forming a stent of desired length from a tube, the tube comprising two or more discrete stent sections, each stent section being connected to an adjacent stent section by a severable link to allow the tube to be cut to the desired length, the method comprising cutting at least one link to form a stent of desired length.
20. A method for forming a stent of desired length from a tube, the tube being in accordance with any one of claims 1 to 17, the method comprising cutting at least one link to form a stent of desired length
21. A method according to claim 19 or claim 20 wherein the method comprises cutting the at least one link with a scalpel.
22. A stent formed according to the method of any one of claims 19 to 21.
23. A method for treating a stenosed body lumen, the method comprising positioning a stent in the stenosis, the stent being in accordance with claim 18 or claim 22.
PCT/AU2000/001552 1999-12-15 2000-12-15 Stent WO2001043810A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU23283/01A AU2328301A (en) 1999-12-15 2000-12-15 Stent

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPQ4645 1999-12-15
AUPQ4645A AUPQ464599A0 (en) 1999-12-15 1999-12-15 The O-Z stent: improved intra-coronary stent for the treatment of multiple coronary stenoses of variable length

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WO2001043810A1 true WO2001043810A1 (en) 2001-06-21

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008070423A1 (en) * 2006-12-01 2008-06-12 Medtronic Vascular Inc. Bifurcated stent with variable length branches
CN112568964A (en) * 2020-11-30 2021-03-30 赛诺神畅医疗科技有限公司 Thrombus taking support and thrombus taking device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0540290B1 (en) * 1991-10-28 1998-01-28 Advanced Cardiovascular Systems, Inc. Expandable stents
WO1998030172A1 (en) * 1997-01-10 1998-07-16 Laboratoires Nycomed S.A. Device capable of being implanted for treating a corporeal duct
WO1999001086A1 (en) * 1997-06-30 1999-01-14 Corotec Medizintechnik Gmbh Intraluminal implant
WO1999039661A2 (en) * 1998-02-05 1999-08-12 Medtronic, Inc. Radially-expandable stent and delivery system
WO2000002502A1 (en) * 1998-07-08 2000-01-20 Scimed Life Systems, Inc. An improved stent

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0540290B1 (en) * 1991-10-28 1998-01-28 Advanced Cardiovascular Systems, Inc. Expandable stents
WO1998030172A1 (en) * 1997-01-10 1998-07-16 Laboratoires Nycomed S.A. Device capable of being implanted for treating a corporeal duct
WO1999001086A1 (en) * 1997-06-30 1999-01-14 Corotec Medizintechnik Gmbh Intraluminal implant
WO1999039661A2 (en) * 1998-02-05 1999-08-12 Medtronic, Inc. Radially-expandable stent and delivery system
WO2000002502A1 (en) * 1998-07-08 2000-01-20 Scimed Life Systems, Inc. An improved stent

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008070423A1 (en) * 2006-12-01 2008-06-12 Medtronic Vascular Inc. Bifurcated stent with variable length branches
CN112568964A (en) * 2020-11-30 2021-03-30 赛诺神畅医疗科技有限公司 Thrombus taking support and thrombus taking device

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