Shape Memory Polymer Prosthetic Medical Device

• US 20100152839A1
• Filed: 10/29/2009
• Published: 06/17/2010
• Est. Priority Date: 10/29/2008
• Status: Active Grant

• Current Assignee: EndoShape, Inc
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Scott, Timothy Francis, Lyons, Michael B., Nelson, Avery, Rech, Bryan, Castleberry, Jeffrey Paul, Nair, Devatha P., Shandas, Robin
• Granted Patent: US 9,119,714 B2
• Time in Patent Office: Days
• US Class Current: 623/1.240
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2/2436 Deployment by retracting a sheath
• CPC Class Codes: A61F 2/2469 with resilient valve members, e.g. conical spiral
• CPC Class Codes: A61F 2/2475 Venous valves
• 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 2230/0091 helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: B29C 61/0608 characterised by the configuration or structure of the preforms
• CPC Class Codes: B29L 2031/7534 Cardiovascular protheses
• CPC Class Codes: Y10T 156/1031 with preshaping of lamina

Abstract

A prosthetic medical device is formed by the combination of a biological tissue a shape memory polymer structure. The biological tissue provides an in-situ physiological function of the device. The shape memory polymer provides a capability for minimizing the device profile during insertion and then deploying after placement into a memory shape that achieves suitable mechanical structure and stability within an anatomical lumen or cavity. This configuration may be applied to form various prosthetic devices including aortic, mitral, and tricuspid valves in the heart; venous valves; anti-reflux valves for the lower esophageal sphincter; and other biological valve structures. Alternatively, an entirely non-biologic implementation using only shape memory polymer-based structures may be used as a prosthetic valve device.

Claims

1. A method for making a prosthetic medical device comprising

configuring a prosthetic body from a shape memory polymer material in a first, post-transition form designed to fit snugly against a wall of a anatomical lumen;

affixing a biological tissue that performs a physiological function to and within the prosthetic body; and

deforming the prosthetic body into a second, pre-transition form that comprises a compact shape or profile relative to the first form for insertion into a delivery device for in vitro placement of the prosthetic medical device.

2. The method of claim 1, wherein the affixing operation further comprises affixing the biological tissue to the shape memory polymer body with an adhesive.

3. The method of claim 1, wherein the affixing operation further comprises polymerizing the shape memory polymer material around the biological tissue during the configuration operation.

4. The method of claim 1, wherein the affixing operation further comprises mechanically fastening the biological tissue to the prosthetic body with a mechanical fastener.

5. The method of claim 1, wherein a transition of the valve body from the second form to the first form occurs in response to a temperature stimulus.

6. A prosthetic medical device comprising

a shape memory polymer valve body defining a lumen;

and

a biological venous valve positioned within the lumen and affixed to the valve body, wherein

the valve body is configured to deform to a smaller form factor for delivery to an anatomical lumen; and

upon delivery and in reaction to a stimulus, the valve body is configured to transition to a memory form that lodges within the anatomical lumen.

7. The prosthetic medical device of claim 6, wherein the valve body is formed as a stent.

8. The prosthetic medical device of claim 7 wherein the stent forms a substantially cylindrical outer wall and defines a longitudinal slit within the outer wall allowing opposing ends of the outer wall adjacent the slit to slide past each other and reduce a diameter of the stent in a pre-transition form.

9. The prosthetic medical device of claim 7, where in the stent is fenestrated allowing the stent to collapse into a pre-transition form.

10. The prosthetic medical device of claim 6, wherein the biological venous valve is affixed to the valve body with an adhesive.

11. The prosthetic medical device of claim 6, wherein the biological venous valve is affixed to the valve body with a mechanical fastener.

12. The prosthetic medical device of claim 6, wherein an outer surface of the valve body is formed with a plurality of anchor structures to engage a wall of an anatomical lumen and resist migration of the prosthetic venous valve device within the anatomical lumen.

13. A method for treating venous degeneration comprising

inserting a catheter within a vein of a patient;

delivering within the vein via the catheter a prosthetic venous valve device comprising a shape memory polymer valve body and a biological venous valve affixed to and within the valve body; and

expanding the valve body to fit snugly against a wall of a lumen of the vein.

14. The method of claim 13, further comprising delivering a plurality of the prosthetic venous valve device in series within the lumen of the vein.

15. The method of claim 13 further comprising constraining the shape memory polymer valve body within the catheter before the expanding operation.

16. A method for making a prosthetic medical device comprising

configuring a prosthetic body from a material comprising a shape memory polymer in a first, post-transition form designed to fit snugly against a wall of an anatomical lumen, wherein the prosthetic body further comprises

an outer body defining an interior lumen;

one or more valve flaps attached to the outer body within the interior lumen and arranged to resist retrograde fluid flow within the interior lumen; and

deforming the prosthetic body into a second, pre-transition form that comprises a compact shape or profile relative to the first form for insertion into a delivery device for in vitro placement of the prosthetic medical device.

17. The method of claim 16, wherein

the valve flaps comprise a biological tissue;

and

the method further comprises affixing the biological tissue to the outer body within the lumen.

18. The method of claim 17, wherein the affixing operation further comprises affixing the biological tissue to the shape memory polymer body with an adhesive.

19. The method of claim 17, wherein the affixing operation further comprises polymerizing the shape memory polymer material around the biological tissue during the configuration operation.

20. The method of claim 17, wherein the affixing operation further comprises mechanically fastening the biological tissue to the prosthetic body with a mechanical fastener.

21. A prosthetic medical device comprising

a shape memory polymer valve body defining an interior lumen;

and

one or more valve flaps attached to the valve body within the interior lumen and arranged to resist retrograde fluid flow within the interior lumen, wherein

the valve body is configured to deform to a smaller form factor for delivery to an anatomical lumen; and

upon delivery and in reaction to a stimulus, the valve body is configured to transition to a memory form that lodges within the anatomical lumen.

22. The prosthetic medical device of claim 21, wherein the one or more valve flaps are formed of the shape memory polymer.

23. The prosthetic medical device of claim 21, wherein the one or more valve flaps are formed of a biological tissue attached to the valve body.

24. The prosthetic medical device of claim 21, wherein the valve body comprises a substantially cylindrical stent.

25. The prosthetic medical device of claim 24, wherein the stent is fenestrated.

26. The prosthetic medical device of claim 21, wherein the valve body comprises a coil stent.

27. The prosthetic medical device of claim 21, wherein the one or more valve flaps comprises a single valve flap that forms a helical web within the interior lumen and further defines a center passage along an axis of the interior lumen.

28. The prosthetic medical device of claim 21, wherein the one or more valve flaps comprise a plurality of valve leaflets, which may or may not coapt across the interior lumen, and which are configured to produce a preferential flow resistance within the interior lumen in one direction such that a valve function is generated from a differential between a forward and a reverse pressure gradient.

29. The prosthetic medical device of claim 21, wherein the one or more valve flaps taper in thickness from a flap base adjacent the valve body to a leading edge distal from the valve body.

30. A method for treating venous degeneration comprising

inserting a catheter within a vein of a patient;

delivering within the vein via the catheter a prosthetic venous valve device formed of a shape memory polymer and further comprising

an outer body defining an interior lumen;

one or more valve flaps attached to the outer body within the interior lumen and arranged to resist retrograde fluid flow within the interior lumen; and

expanding the outer body to fit snugly against a wall of a lumen of the vein.

31. The method of claim 30, further comprising delivering a plurality of the prosthetic venous valve device in series within the lumen of the vein.