Expandable introducer sheath
An expandable introducer sheath for use in inserting a medical device into a body vessel of a patient includes a body which extends from a proximal end to a distal end along an axis. The body includes an inner layer, an outer layer, and an expandable reinforcement member which is disposed between said inner and outer layers. The expandable reinforcement member is configured to radially expand as the medical device is axially advanced or retracted through said introducer sheath. Once the medical device has exited the introducer sheath, the expandable reinforcement member facilitates a return of the introducer sheath to its original or unexpanded condition.
1. An expandable introducer sheath for use in inserting a medical device into a body vessel of a patient comprising:
a body extending from a proximal end to a distal end along an axis A;
said body including an inner layer, an outer layer, and an expandable reinforcement member disposed between said inner and outer layers;
said expandable reinforcement member configured to radially expand as the medical device is axially advanced or retracted through the introducer sheath; and
a protective sheath disposed in overlaying and surrounding relationship with said outer layer and radially expandable in conjunction with said outer layer and said expandable reinforcement member during axial movement of the medical device through the introducer sheath.
2. An expandable introducer sheath as set forth in claim 1 , wherein said expandable reinforcement member includes a spine extending between said proximal and distal ends and a plurality of ribs extending radially from said spine and circumferentially about said axis A.
3. An expandable introducer sheath as set forth in claim 1 , wherein said expandable reinforcement member includes a single wire which extends continuously between said proximal and distal ends.
4. An expandable introducer sheath as set forth in claim 3 , wherein said single wire is wrapped to define a series of loops, with each of said loops in said series of loops extending circumferentially about said axis A and being interleaved between adjacent loops of said series of loops.
5. An expandable introducer sheath as set forth in claim 4 , wherein said adjacent loops of said series of loops extend in opposite radial circumferential directions relative to one another for allowing said adjacent loops to slide relative to one another and effectuate radial expansion of said reinforcement member as the medical device is introduced into said introducer sheath.
6. An expandable introducer sheath as set forth in claim 1 , wherein said expandable reinforcement member includes a plurality of struts disposed in spaced relationship to one another and each extending longitudinally between said proximal and distal ends and a plurality of linkages each extending radially between adjacent spines.
7. An expandable introducer sheath as set forth in claim 6 , wherein said each of the linkages are radially expandable from their contracted or static position as a medical device is introduced into the introducer sheath, and are configured to return or spring back to the contracted position when the medical device exits the introducer sheath.
8. An expandable introducer sheath as set forth in claim 6 , wherein said expandable reinforcement member is fabricated by laser cutting a tube.
9. An expandable introducer sheath as set forth in claim 1 , wherein said expandable reinforcement member is comprised of a shape memory material to facilitate a return of said expandable reinforcement member to its unexpanded condition following an exit of the medical device from said introducer sheath.
10. An expandable introducer sheath as set forth in claim 9 , wherein said expandable reinforcement member is comprised of Nitinol or stainless steel.
11. An expandable introducer sheath as set forth in claim 9 , wherein said expandable reinforcement member is comprised of a rigid thermoplastic material.
12. An expandable introducer sheath as set forth in claim 1 , wherein said inner layer is comprised of a lubricous, low friction polymeric material.
13. An expandable introducer sheath as set forth in claim 12 , wherein said inner layer is comprised of expandable polytetrafluoroethylene (ePTFE).
14. An expandable introducer sheath as set forth in claim 1 , wherein said outer layer is comprised of a thermoplastic material.
15. An expandable introducer sheath as set forth in claim 1 , wherein said protective sheath is comprised of expandable polytetrafluoroethylene (ePTFE).
16. An expandable introducer sheath as set forth in claim 1 , wherein said outer layer includes at least one slit which extends longitudinally and is disposed between said proximal and distal ends.
17. An expandable introducer sheath as set forth in claim 16 , wherein said inner layer includes a fold disposed in aligned relationship with said at least one slit of said outer layer.
18. An expandable introducer sheath as set forth in claim 1 , wherein said body includes an enlarged portion disposed adjacent said proximal end, said enlarged portion having a first diameter being complementary to the medical device.
19. An expandable introducer sheath as set forth in claim 18 , wherein said body includes a tapered portion extending from said distal end to said enlarged portion, said tapered portion having a second diameter being smaller than said first diameter of said enlarged portion for providing a smaller profile of said introducer sheath to facilitate an initial insertion into the body vessel.