Length extensible implantable device and methods for making such devices

1. An implantable device having an extendible length, the implantable device comprising:

a porous member comprising a microstructure including a multiplicity of fibrils,

wherein the porous member comprises a longitudinally uncompressed configuration and a longitudinally compressed configuration, wherein a mean fibril length in the longitudinally uncompressed configuration is greater than a mean fibril length in the longitudinally compressed configuration and a compressed length of the porous member in the longitudinally compressed configuration is approximately between 50% and 75% of an extended length of the porous member in the longitudinally uncompressed configuration; and

a first longitudinal constraining member secured to the porous member along a length of the porous member by an adhesive, the first longitudinal constraining member maintaining at least a portion of an abluminal surface of the porous member in the longitudinally compressed configuration with a constraining force, the first longitudinal constraining member being configured to release the constraining force upon application of a radial force within a lumen of the porous member while patency of the lumen of the porous member is maintained and upon release of the constraining force, at least a segment of the porous tubular member is configured to expand to and maintain the extended length relative to a longitudinal axis of the porous member in the absence of the radial force.

2. The implantable device of claim 1 , further comprising a second porous member covering the longitudinal constraining member.

3. The implantable device of claim 1 , wherein the porous member is a tubular member.

4. The implantable device of claim 1 , wherein the first longitudinal constraining member comprises a porous ePTFE film.

5. The implantable device of claim 4 , wherein the porous ePTFE film is wrapped over the at least a portion of the abluminal surface of the porous member at an angle relative to the longitudinal axis of the porous member.

6. The implantable device of claim 1 , wherein the first longitudinal constraining member covers more than one portion of the abluminal surface of the porous member.

7. The implantable device of claim 1 , wherein the first longitudinal constraining member covers the entire abluminal surface of the porous member.

8. The implantable device of claim 1 , wherein the microstructure of the porous member includes a multiplicity of nodes.

9. The implantable device of claim 1 , further comprising at least a second longitudinal constraining member.

10. The implantable device of claim 9 , wherein the first and second longitudinal constraining members cover different portions of the abluminal surface of the porous member.

11. The implantable device of claim 1 , wherein at least a segment of the first longitudinal constraining member is ruptured by applying a longitudinal force to the longitudinal constraining member and the porous member, wherein upon rupturing, at least a portion of the porous member covered by the segment of first longitudinal constraining member longitudinally extends.

12. The implantable device of claim 1 , wherein the

porous member is a porous ePTFE member, and further wherein the longitudinally compressed configuration of the porous ePTFE member comprises a longitudinally compressed portion including bent fibrils.

13. The implantable device according to claim 12 wherein the porous ePTFE member is a tubular member.

14. The implantable device of claim 13 , wherein the first longitudinal constraining member is a perforated sleeve.

15. The implantable device of claim 13 , wherein the first longitudinal constraining member comprises a film wrapped around at least a portion of the abluminal surface of the porous member at an angle relative to a longitudinal axis of the porous member.

16. The implantable device of claim 12 , wherein the constraining member comprises a porous ePTFE film.

17. The implantable device of claim 16 , wherein the porous ePTFE film has a plurality of nodes interconnected by fibrils, wherein the nodes are generally aligned so as to be substantially parallel to each other.

18. The implantable device of claim 12 , wherein upon application of an elongating force to the porous ePTFE member, the first longitudinal constraining member ruptures and permits elongation of the longitudinally compressed portion from a first length to a second length, wherein upon release of the elongating force, the elongated compressed portion recovers to a third length shorter than the second length and longer than the first length.

19. The implantable device of claim 12 , further comprising a stent having an inner surface and an outer surface, the porous member and longitudinal constraining member covering at least a portion of at least one of the inner and outer surfaces of the stent.

20. The implantable device of claim 12 , wherein the porous ePTFE member comprises the longitudinally compressed portion and a longitudinally uncompressed portion.

21. The implantable device of claim 20 , wherein a mean fibril length in the longitudinally uncompressed portion is greater than a mean fibril length in the longitudinally compressed portion.

22. An implantable device having an extendible length, the implantable device comprising:

a porous member comprising a microstructure including a multiplicity of fibrils,

wherein the porous member comprises a longitudinally uncompressed configuration and a longitudinally compressed configuration, wherein a mean fibril length in the longitudinally uncompressed configuration is greater than a mean fibril length in the longitudinally compressed configuration and a compressed length of the porous member in the longitudinally compressed configuration is approximately between 50% and 75% of an extended length of the porous member in the longitudinally uncompressed configuration; and

a first longitudinal constraining member secured to the porous member along a length of the porous member by an adhesive, the first longitudinal constraining member maintaining at least a portion of an abluminal surface of the porous member in the longitudinally compressed configuration with a constraining force, the first longitudinal constraining member being configured to release the constraining force upon application of a radial force within a lumen of the porous member while patency of the lumen is maintained and upon release of the constraining force, at least a segment of the porous tubular member is configured to expand to and maintain the extended length relative to a longitudinal axis of the porous member in the absence of the radial force.

23. An implantable device having an extendible length, the implantable device comprising:

a porous member comprising a microstructure including a multiplicity of fibrils,

wherein the porous member comprises a longitudinally uncompressed configuration and a longitudinally compressed configuration, wherein a mean fibril length in the longitudinally uncompressed configuration is greater than a mean fibril length in the longitudinally compressed configuration and a compressed length of the porous member in the longitudinally compressed configuration is approximately between 50% and 75% of an extended length of the porous member in the longitudinally uncompressed configuration; and

a first longitudinal constraining member secured to the porous member along a length of the porous member by an adhesive, the first longitudinal constraining member maintaining at least a portion of an abluminal surface of the porous member in the longitudinally compressed configuration with a constraining force, the first longitudinal constraining member being configured to release the constraining force upon application of a radial force within a lumen of the implantable device to permit the porous member to extend from the longitudinally compressed configuration to expand and maintain the extended length relative to a longitudinal axis of the porous member in the absence of the radial force.