Stent delivery system

• US 6,371,979 B1
• Filed: 02/21/1997
• Issued: 04/16/2002
• Est. Priority Date: 01/27/1993
• Status: Expired due to Term

• Current Assignee: Ev3 Peripheral Inc. (Medtronic Plc)
• Original Assignee: Intratherapeutics Incorporated (Sulzer Medica)
• Inventors: Beyar, Mordechay, Globerman, Oren, Beyar, Rafael
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US08/803,324
• Time in Patent Office: 1,880 Days
• Field of Search: 606/108, 623/1, 623/12, 623/1.11, 623/1.12, 623/1.17, 623/1.2, 623/1.22
• US Class Current: 623/1.12
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2002/9511 the retaining means being filaments or wires
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation

Abstract

This invention is directed to a stent delivery system for implanting a flexible, generally cylindrical, expandable, coiled stent. The system comprises a catheter defining at least one lumen and having at least two longitudinally displaced openings or sets of openings ,a flexible, self-expandable coiled stent having discrete proximal and distal end sections, said stent being wound circumferentially around said catheter and coils of the stent being more closely wound at the proximal and/or distal end sections, and one or two release wires cooperating with restraining means so that as the release wire or wires are with-drawn proximally, the proximal and distal end sections of the stent are released in such a manner that coils of the stent unwind and the length of the unwound stent is not substantially less than the length of the portion of the unreleased stent that is not more closely wound.

Claims

1. A stent delivery system for implanting a flexible, generally cylindrical, self-expanding stent, comprising:

a catheter having distal and proximal ends, said catheter defining at least one lumen extending therethrough and having at least three longitudinally displaced openings or sets of openings extending from a lumen to the surface of the catheter;

a flexible, self-expandable coiled stent in a form of a continuous helical coil with a uniform winding direction and voids defined between opposing turns of said coil, said stent having proximal and distal end sections separated by an intermediate section, said stent being wound circumferentially around said catheter defining a wound position with turns of the coil in at least a selected one of the proximal and distal sections being more closely wound with a narrower spacing between opposing turns than a winding and spacing between opposing turns in said intermediate section;

said stent releasably secured to said catheter at proximal, distal and intermediate fixation points with said intermediate fixation point positioned at said intermediate section, said stent releasable from said wound position to an expanded position in a sequence with said selected one of said proximal and distal sections released from said catheter and expanded radially outward in response to said release prior to said intermediate section being released from said catheter at said intermediate fixation point.

2. A system according to claim 1 wherein both of said proximal and distal sections are more closely wound with a narrower spacing between opposing turns than a winding and spacing between opposing coils in said intermediate section.

3. A system according to claim 2 wherein said stent is releasably secured to said catheter with said stent releasable from said catheter in a sequence with said distal section released from said catheter prior to release of said proximal section from said catheter.

4. A system according to claim 1 wherein said intermediate section of said stent is in substantially the same position when said stent is in said wound position and said expanded position.

5. A stent deliverysystem for implanting a flexible, generally cylindrical, self-expanding stent, comprising:

a catheter having distal and proximal ends and an outer surface, said catheter defining at least one lumen extending therethrough;

a flexible, self-expandable coiled stent in a form of a continuous helical coil with a uniform wining direction and voids defined between opposing turns of said coil, said stent having proximal and distal end section separated by an intermediate section, said stent being wound circumferentially around said catheter defining a wound position with turns of the coil in both the proximal and distal sections being more closely wound with a narrower spacing between opposing turns than a winding and spacing between opposing turns in an other portion of said stent, said other portion of said stent including at least said intermediate section and having a predetermined longitudinal length when in said wound position;

said stent releasably secured to said catheter with said stent releasable from said wound position to an expanded position in a sequence with said proximal and distal sections released first from said catheter and expanded radially outward in response to said release before said other portion of said stent is expanded radially outward, wherein said intermediate section is released from said catheter after said distal and proximal sections are released from said catheter, wherein a longitudinal length of said stent in said expanded position is not substantially less than said predetermined longitudinal length of said other portion of said stent; and

said catheter including grooves formed on the outer surface of the catheter, the grooves corresponding to at least a section of the coil of the stent.

6. A method for deploying a stent using a delivery system, the delivery system including a catheter having a distal end and a proximal end, the catheter including a stent mounting location adjacent to the distal end, the delivery system also including a self-expandable coil stent mounted at the mounting location, the stent having a first end and a second end, wherein the first end is a proximal end of the stent and the second end is a distal end of the stent, the stent including coils having a first spacing adjacent the first end of the stent and also including coils at an intermediate location having a second spacing, the first spacing being narrower than the second spacing such that the coils are more closely wound at the first end, the method comprising:

deploying the stent by initially releasing the first end of the stent such that the stent self-expands in a sequence that starts at the closely wound portion of the first end and moves along the length of the stent from the first end of the stent toward the second end of the stent; and

releasing the second end of the stent after the stent has self-expanded.

7. The method of claim 6, wherein the first and second spacings between the coils change as the stent unwinds from the first end toward the second end.

8. The method of claim 6, wherein during self-expansion the coils of the stent are not restrained.

9. A method for deploying a stent using a delivery system, the delivery system including a catheter having a distal end and a proximal end, the catheter including a stent mounting location adjacent the distal end, the delivery system also including a coil stent mounted at the mounting location, the stent having a distal end and a proximal end, the stent including coils having a first spacing adjacent the proximal end of the stent and also including coils at an intermediate location having a second spacing, the first spacing being narrower than the second spacing, the delivery system also including a first release wire extending longitudinally through the catheter for releasing the proximal end of the stent from the catheter and a second release wire extending longitudinally through the catheter for releasing the distal end of the stent from the catheter, the method comprising:

delivering the stent with the catheter to a delivery site within a patient;

releasing the proximal end of the stent by pulling back the first release wire;

after the proximal end of the stent has been released, self-expanding the stent with the expansion of individual coils of the stent starting at the proximal end and moving along a length of the stent toward the distal end; and

releasing the distal end of the stent after the stent has been self-expanded by pulling back the second release wire.

10. A delivery system comprising:

a catheter having a proximal end and a distal end, the catheter including a stent mounting location positioned adjacent the distal end, the catheter defining at least one lumen extending longitudinally there through, the catheter also defining at least one stent mounting opening defined adjacent to the stent mounting location, the stent mounting opening extending from the lumen to an outer surface of the catheter;

a self-expandable stent mounted at the stent mounting location of the catheter;

a stent retaining member for securing the stent to the catheter, the stent retaining member having a first end connected to the catheter adjacent to the stent mounting location, the retaining member also including a free end that loops over a portion of the stent and extends inwardly through the stent mounting opening to the lumen of the catheter; and

a release wire that extends longitudinally through the lumen and that connects to the free end of the stent retaining member, where the stent is released from the catheter by pulling back on the release wire such that the release wire disengages from the stent retaining member thereby allowing the stent to self expand.