Stent securement sleeves and optional coatings and methods of use

• US 6,478,814 B2
• Filed: 09/28/1999
• Issued: 11/12/2002
• Est. Priority Date: 06/14/1999
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: St. Germain, Jon, Wang, Lixiao, Blaeser, David J., Chen, John Jianhua, Tran, The Thomas Trinh
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US09/407,836
• Publication Number:
  US 20010032008A1
• Time in Patent Office: 1,141 Days
• Field of Search: 623/1.1, 623/1.12, 623/1.44, 623/1.45, 623/1.11, 606/108, 606/198, 606/191, 606/192, 606/194, 606/428
• US Class Current: 623/1.12
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/9583 Means for holding the stent on the balloon, e.g. using protrusions, adhesives or an outer sleeve
• CPC Class Codes: A61F 2002/9665 with additional retaining means
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity

Abstract

A stent delivery system which has a catheter including an inflatable portion. A stent being disposed about the inflatable portion of the catheter, the stent having a contracted state and an expanded state. A pair of stent retaining sleeves which are partially composed of PTFE, each sleeve having a first end portion overlying a respective end of the stent, each sleeve having a second end portion respectively attached to the catheter, the sleeves retaining the stent to the catheter when the stent is in the contracted state, the stent being freed from the sleeves when the stent is placed in the expanded state. The sleeves being placed on the stent by heat shrinking. The inflatable portion of the balloon optionally having stepped compliant characteristics.

Claims

1. A stent delivery system comprising:

a catheter including an inflatable portion;

a stent disposed about the inflatable portion of the catheter, the stent having a distal end and a proximal end, the stent further having a contracted state and an expanded state, and

a pair of stent retaining sleeves which are at least partially composed of PTFE, each sleeve having a first end portion overlying a respective end of the stent, each sleeve having a second end portion respectively attached to the catheter, the sleeves retaining the stent to the catheter when the stent is in the contracted state, the stent being freed from the sleeves when the stent is placed in the expanded state, wherein the stent retaining sleeves are flexible.

2. The stent delivery system of claim 1 wherein the stent retaining sleeves have a composite construction of PTFE material and non-PTFE material.

3. The stent delivery system of claim 2 wherein the non-PTFE material is one or more thermoplastic elastomeric materials.

4. The stent delivery system of claim 3 wherein the one or more thermoplastic elastomeric materials are selected from the group consisting of:

block copolymers;

copolymers and terpolymers of ethylene;

homopolymers, copolymers and terpolymers of propylene;

ethylene α

-olefins;

polyurethanes;

vinyl copolymers;

ionomer materials, or any combination thereof.

5. The stent delivery system of claim 4 wherein the one or more thermoplastic elastomeric materials are selected from the group consisting of:

polyether-polyester block copolymers, polyether block amide copolymers, polyvinyl chloride, polyetherurethanes, polyesterurethanes, polyurethane ureas, polyurethane siloxane block copolymers, silicone polycarbonate copolymers, ethylene vinyl acetate copolymers, copolyesters or any combination thereof.

6. The stent delivery system of claim 3 wherein the PTFE material and the one or more thermoplastic elastomeric materials are interconnected.

7. The stent delivery system of claim 3 wherein a layer of PTFE material is at least partially interconnected with a layer of one or more thermoplastic elastomeric materials, the layer composed of PTFE material at least partially protruding from the one or more thermoplastic elastomeric materials, the layer of PTFE material overlying the stent ends, the layer of one or more thermoplastic elastomeric materials attached to the catheter.

8. The stent delivery system of claim 3 wherein the stent retaining sleeves each have an inside surface and an outside surface, at least a portion of the inside surface composed of PTFE, the outside surface composed of one or more thermoplastic elastomeric materials.

9. The stent delivery system of claim 8 wherein the at least a portion of the inside surface is in contact with the stent when the stent is in the contracted state.

10. The stent delivery portion of claim 1 wherein the inflatable portion has a stepped compliance curve.

11. The stent delivery system of claim 1 wherein the inflatable portion further comprises one or more stepped compliant portions, and at least one linear compliant portion, the one or more stepped compliant portions characterized as having a stepped compliance curve, the at least one linear compliant portion characterized as having a generally linear compliance curve to burst pressure.

12. A stent delivery system comprising:

a catheter, the catheter having an inflatable section, the inflatable section having a body portion and a pair of end portions, the body portion having a generally linear compliance curve to burst pressure and the end portions respectively having a stepped compliance curve characterized by a low pressure segment defined by a low inflation pressure range, said low pressure segment being generally collinear with a corresponding segment of the compliance curve of the body portion which is defined by said low inflation pressure range, a transition segment during which the inflatable section expands rapidly relative to the body portion and a high pressure segment during which the compliance curve of the end portions expands slowly relative to the transition region;

a stent disposed at least partially about the inflatable section, the stent having a distal end and a proximal end, the stent further having a contracted state and an expanded state, and

a pair of stent retaining sleeves, each sleeve having a first end portion overlying a respective end of the stent and an end portion of the inflatable section, each sleeve having a second end portion respectively attached to the catheter, the sleeves retaining the stent to the catheter when the stent is in the contracted state, the stent being freed from the sleeves when the stent is placed in the expanded state, wherein the pair of stent retaining sleeves are at least partially composed of PTFE, wherein the stent retaining sleeves have a composite construction of PTFE material and non-PTFE material and are flexible.

13. A stent delivery system comprising:

a catheter including a stent mounting region constructed and arranged to carry and release a stent;

a stent disposed about the stent mounting region of the catheter, the stent having a first end and a second end, the stent further having a contracted state and an expanded state, and

a pair of stent flexible retaining sleeves, the stent retaining sleeves, being constructed at least partially from PTFE and having an inside surface and an outside surface, the inside surface and the outside surface being coated with a hydrophobic material.

14. The stent delivery system of claim 13, wherein the stent retaining sleeves include a thermoplastic elastomer layer.

15. The stent delivery system of claim 13 wherein the hydrophobic material is selected from the group consisting of:

silicone based lubricants, slip agents or a combination thereof.

16. A stent delivery system comprising:

a catheter including a stent mounting region constructed and arranged to carry and release a stent;

a stent disposed about the stent mounting region of the catheter, the stent having a first end and a second end, the stent further having a contracted state and an expanded state, and

a pair of stent retaining sleeves, the stent retaining sleeves having an inside surface and an outside surface, the inside surface at least partially coated with a hydrophobic material, the outside surface at least partially coated with a hydrophilic material, each sleeve having a first end portion overlying a respective end of the stent, each sleeve having a second end portion respectively attached to the catheter, the stent being freed from the sleeves when the stent is placed in the expanded state.

17. The stent delivery system of claim 16 wherein the hydrophobic material is selected from the group consisting of:

silicone based lubricants, slip agents or a combination thereof.

18. The stent delivery system of claim 16 wherein the hydrophilic material is selected from the group consisting of:

polyethylene oxide and its copolymers;

polyvinylpyrrolidone and its derivatives;

polyacrylate, polyacrylic acid, polyacrylamide, polyethylene maleic anhydride, or any combination thereof.

19. A method of attaching a stent retaining sleeve to a catheter comprising the steps of:

(a) providing a catheter which includes a distal portion constructed and arranged to carry and release a stent, the stent at least partially disposed about the distal portion of the catheter, the stent having a first end and a second end, the stent further having a contracted state and an expanded state;

(b) stretching a stent retaining sleeve having a first end and a second end and comprising at least one thermoplastic elastomer and PTFE material to a predetermined extent, wherein the stent retaining sleeve is flexible;

(c) placing the stent retaining sleeve over the distal portion of the catheter and at least one of the stent ends; and

(d) contracting the stent retaining sleeve about the catheter, attaching the first end of the retaining sleeve thereto, and the at least one of the stent ends.

20. The method of attaching a stent retaining sleeve to a catheter of claim 19 wherein the stent retaining sleeve is exposed to a temperature between 25 degrees Celsius and 70 degrees Celsius during the stretching and contracting steps.

21. The method of attaching a stent retaining sleeve to a catheter of claim 19 wherein the stent retaining sleeve is exposed to a temperature of 50 degrees Celsius during the stretching and contracting steps.

22. The method of attaching a stent retaining sleeve to a catheter of claim 19 wherein a stent retaining sleeve is stretched over both of the respective stent ends.

23. The method of attaching a stent retaining sleeve to a catheter of claim 19 wherein the at least one thermoplastic elastomer may be selected from the group consisting of, polyurethane, polycarbonateurethane, polyamide elastomer, polyolefin elastomer and polyester elastomer or any combination thereof.

24. A stent delivery system comprising:

a catheter, the catheter having an inflatable section, the inflatable section having a first inflation state and a second inflation state, the inflatable section having a body region positioned between first and second end regions, the body region and each said end region having a respective diameter in each said inflation state, in the second inflation state the body region diameter being greater than the first and second end region diameters;

an expandable stent disposed at least partially about the inflatable section, the stent having a distal end and a proximal end; and

a pair of stent retaining sleeves, in the first inflation state each sleeve having a first end portion overlying a respective end of the stent and one of the end regions of the inflatable section, each sleeve having a second end portion respectively engaged to the catheter adjacent to the inflatable section, the pair of stent retaining sleeves retaining the stent to the catheter when the inflatable section is in the first inflation state, wherein the pair of stent retaining sleeves are at least partially composed of PTFE.

25. The stent delivery system of claim 24 wherein the pair of stent retaining sleeves have a composite construction of PTFE material and non-PTFE material and are flexible.