PROTECTIVE SHEATH ASSEMBLY FOR A POLYMER SCAFFOLD

• US 20140379064A1
• Filed: 06/21/2013
• Published: 12/25/2014
• Est. Priority Date: 06/21/2013
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Pacetti, Stephen D., Liu, Annie P., Johnson, Mark C.
• Granted Patent: US 9,675,483 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/0095 Packages or dispensers for prostheses or other implants for intraocular lenses A61F2/1691; for dental surgery A61C19/02
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2/97 the outer sleeve being splittable
• 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 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2250/0059 temporary
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body

Abstract

A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. A sheath is placed over the crimped scaffold after crimping to reduce recoil of the crimped polymer scaffold and maintain scaffold-balloon engagement relied on to hold the scaffold to the balloon when the scaffold is being delivered to a target in a body. The sheath is removed by a health professional either by removing the sheath directly or using a tube containing the catheter.

Claims

1. An apparatus, comprising:

a catheter including a scaffold comprising a polymer, the scaffold being crimped to a balloon;

a sheath disposed over the scaffold;

a tube containing at least a portion of the catheter; and

a member disposed within the tube, wherein the member partially or fully removes the sheath from the scaffold when the tube is separated from the catheter; and

wherein the catheter is configured for being introduced into a mammalian body only after the sheath is removed from the scaffold.

2. The apparatus of claim 1, wherein the scaffold is formed from a radially expanded tube having a pre-crimp diameter that is at least about 1.5, 2, 3, or 4 times the crimped diameter of the scaffold.

3. The apparatus of claim 1, wherein the member is disposed at an end of the catheter or the tube.

4. The apparatus of claim 1, wherein the tube is rigid compared to the sheath.

5. The apparatus of claim 1, wherein the tube extends substantially the entire length of a shaft of the catheter.

6. The apparatus of claim 1, wherein the sheath includes a constraining portion and a protecting portion, the constraining portion applying a radial inward force on the crimped scaffold to limit recoil of the scaffold.

7. The apparatus of claim 6, wherein the sheath is a two piece sheath.

8. The apparatus of claim 1, wherein the sheath includes a second member that exceeds the clearance, so that the sheath is partially or fully pulled or pushed off the scaffold when the second member encounters the clearance.

9. The apparatus of claim 1, wherein the member is a clip, rim, flange or portion of the tube.

10. An apparatus for delivery of a medical device, comprising:

a balloon catheter including a balloon having a nominal inflation diameter;

a scaffold formed form a radially expanded tube comprising a polymer;

the scaffold being crimped to the balloon and having a crimped diameter, wherein the balloon nominal inflation diameter is about 2, 3 or 4 times greater than the crimped diameter of the scaffold;

a constraining sheath disposed over the scaffold, the sheath being configured for minimizing recoil of the scaffold so as to maintain the crimped diameter; and

a rigid tube containing the catheter;

wherein the catheter is adapted for being passed through a mammalian body only after the catheter is removed from the tube.

11. The apparatus of claim 10, wherein the scaffold has a morphology characterized by (1) substantially radially aligned polymer chains resulting from a biaxial expansion of the scaffold in the radial direction by between about 200 to 400% of a pre-expansion tube diameter, and (2) the scaffold is crimped from the tube or pre-crimp diameter to the crimped diameter that is at least 2-3 times reduced from the tube diameter.

12. The apparatus of claim 11, wherein the scaffold is made from a polymer composition comprising PLLA.

13. The device of claim 10, wherein the polymer chains of the crimped scaffold are aligned substantially in a radial direction resulting from a radial expansion of between about 400% and 450% and axial expansion of between 150% and 200%, or 10% and 50%.

14. The apparatus of claim 10, wherein the tube is configured to partially or fully remove the sheath from the scaffold, or partially or fully remove a sheath constraining portion from the catheter when the catheter is withdrawn from a proximal end the tube.

15. The apparatus of claim 10, wherein the catheter comprises a shaft and a hub and wherein the entire shaft is contained within the tube.

16. A method, comprising:

providing a tube having a lumen, and contained within the lumen a catheter including a scaffold crimped to a balloon, wherein a sheath constrains the scaffold; and

removing the sheath from the catheter by removing the catheter from the tube.

17. The method of claim 16, wherein the tube extends from at least a catheter distal end to a catheter proximal end.

18. The method of claim 16, wherein the scaffold and catheter are configured for implantation within a body only after both the sheath and tube are removed.

19. The method of claim 16, wherein the tube is rigid compared to the sheath

20. The method of claim 16, wherein the removing the sheath step includes engaging a first member of the tube with a second member of the catheter.