Stents with temporary retaining bands

• US 20020116050A1
• Filed: 02/26/2002
• Published: 08/22/2002
• Est. Priority Date: 01/15/1999
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Kocur, Gordon J.
• Granted Patent: US 7,022,132 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/9511 the retaining means being filaments or wires
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2250/0071 breakable or frangible

Abstract

A self-expanding stent is formed of a stent framework and retaining segments disposed about the framework. The retaining segments hold the stent in a partially or fully contracted state in a bodily vessel. The retaining segments are constructed to fail after a predetermined time or upon the application of a predetermined force. Upon failure of the segments, the stent expands in the bodily vessel.

Claims

1. An expandable stent comprising:

an expandable stent framework, the stent framework expandable from a reduced diameter configuration to a fully expanded configuration;

and at least one stent retaining segment disposed about the stent, the stent retaining segment maintaining the stent framework in a less than fully expanded configuration, the stent retaining segment constructed and arranged to fail upon degradation of at least a portion of the segment.

2. The stent of claim 1 comprising a plurality of stent retaining segments.

3. The stent of claim 1 wherein the retaining segment is formed of at least one segment of inert material and at least one segment of biodegradable material joined together.

4. The stent of claim 3 wherein the retaining segment comprises a plurality of alternating inert segments and biodegradable segments joined together.

5. The stent of claim 1 wherein the retaining segment is made of a biodegradable material.

6. The stent of claim 5 wherein the biodegradable material is provided with a treatment agent.

7. The stent of claim 1 wherein the retaining segment is provided with a treatment agent.

8. The stent of claim 1 wherein the retaining segment is disposed on the outside of the stent framework.

9. The stent of claim 1 wherein the retaining segment is interwoven through the stent framework.

10. The stent of claim 1 wherein the retaining segment is constructed to fail after a predetermined period of time in the body.

11. The stent of claim 10 wherein the period of time is at least one month.

12. The stent of claim 10 wherein the retaining segment is in the form of a band disposed about the stent.

13. The stent of claim 1 wherein the stent framework comprises a plurality of interconnected struts and the retaining segment interconnects connects no more than two adjacent struts.

14. The stent of claim 1 wherein the retaining segment is in the form of a web.

16. The stent of claim 15 the retaining segment having a plurality of fatigue points thereon.

17. The stent of claim 15 wherein the retaining segment narrows at the fatigue point.

18. The stent of claim 15 wherein the retaining segment is made of an inert, material.

19. The stent of claim 18 wherein the material is PTFE.

20. The stent of claim 15 wherein the stent retaining segment is constructed to fail after a predetermined amount of time in a bodily lumen.

21. The stent of claim 15 wherein the retaining segment is constructed to fail after at least one month in a bodily lumen.

22. The stent of claim 15 where the stent retaining segment is constructed to fail upon the application thereto of a predetermined force.

24. The method of claim 23 wherein the prosthesis retaining segment is constructed to fail after a predetermined time in a bodily lumen.

25. The method of claim 23 wherein the predetermined time is at least one month.

28. The endoprosthesis of claim 27 wherein the retaining structure is in the form of a segment.

29. The endoprosthesis of claim 27 wherein the retaining structure is in the form of a web.

15. An expandable stent comprising:

an expandable stent framework, the stent framework expandable from a reduced diameter configuration to a fully expanded configuration;

and at least one stent retaining segment disposed about the stent, the stent retaining segment maintaining the stent framework in a less than fully expanded configuration, the stent retaining segment constructed and arranged to have at least one fatigue point thereon.

23. A treatment method comprising the steps of:

i) implanting an expandable prosthesis in a bodily lumen, the expandable prosthesis comprising

1) an expandable prosthesis framework, the prosthesis framework expandable from a reduced diameter configuration to a fully expanded configuration; and

2) a prosthesis retaining segment which is constructed to fail upon dissolution of at least a portion thereof, the segment formed at least in part of a biodegradable material

the prosthesis retaining segment disposed about the prosthesis and maintaining the prosthesis framework in a reduced diameter configuration.

26. A treatment method comprising the steps of:

i) implanting an expandable prosthesis in a bodily lumen, the expandable prosthesis comprising

1) an expandable prosthesis framework, the prosthesis framework expandable from a reduced diameter configuration to a fully expanded configuration; and

2) a prosthesis retaining segment which is constructed to have at least one fatigue point thereon to facilitate failure of the segment under a predetermined set of conditions,

the prosthesis retaining segment disposed about the prosthesis and maintaining the prosthesis framework in a reduced diameter.

27. An expandable medical endoprosthesis for implantation in a bodily vessel comprising:

an expandable prosthesis framework expandable from a reduced diameter configuration to a fully expanded configuration;

and at least one endoprosthesis retaining structure attached to the endoprosthesis framework and disposed about the endoprosthesis framework, the endoprosthesis retaining structure maintaining the endoprosthesis framework in a reduced diameter configuration.