SHEATHS REDUCING RECOIL AND LOSS OF RETENTION FOR POLYMER SCAFFOLDS CRIMPED TO BALLOONS

• US 20150328028A1
• Filed: 05/19/2015
• Published: 11/19/2015
• Est. Priority Date: 12/07/2012
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Wang, Yunbing, Bayogo, Jhoan
• Granted Patent: US 9,579,181 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 2/011 Instruments for their placement or removal
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2/9524 Iris-type crimpers
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2/962 having an outer sleeve
• 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 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0059 temporary
• CPC Class Codes: B23P 11/005 by expanding or crimping
• CPC Class Codes: Y10T 29/49826 Assembling or joining
• CPC Class Codes: Y10T 29/49838 by stringing
• CPC Class Codes: Y10T 29/49909 Securing cup or tube between axially extending concentric annuli
• CPC Class Codes: Y10T 29/49915 Overedge assembling of seated part

Abstract

A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. A single piece sheath is placed over the scaffold immediately following crimping of the scaffold to the balloon. The single piece sheath is replaced by a two-piece sheath, which is removed prior to performing a medical procedure using the medical device.

Claims

1. A method for assembling a medical device, comprising:

providing a catheter including a shaft and a balloon having distal and proximal ends;

crimping a polymer scaffold to the balloon to produce a crimped scaffold;

placing a temporary sheath over the crimped scaffold;

inspecting the crimped scaffold and/or balloon within the temporary sheath;

removing the temporary sheath from the crimped scaffold; and

placing a final sheath over the crimped scaffold;

wherein only after the final sheath is removed is the scaffold configured to be passed through the body of a patient.

3. The method of claim 1, wherein the catheter is sealed within packaging while the crimped scaffold is disposed within the final sheath.

4. The method of claim 1, wherein the inspecting step includes increasing the pressure inside of the balloon and decreasing the pressure within the balloon.

5. The method of claim 1, wherein the temporary sheath is made from a transparent material and the inspecting step includes at least visually inspecting the crimped scaffold while disposed within the temporary sheath.

6. The method of claim 1, wherein the temporary sheath is tubular having first and second ends, the first end is proximal the balloon proximal end and the second end is distal the balloon proximal end, and at least the second end is flared.

7. The method of claim 1, wherein the advancing step further includes deforming a flared end of the temporary sheath to reduce resistance to a sliding of the temporary sheath over the crimped scaffold.

8. The method of claim 1, wherein an end of the temporary sheath disposed adjacent an end of the balloon includes a flared end to facilitate removal of the temporary sheath from the crimped scaffold by tearing the temporary sheath at the flared end.

20. The method of claim 1, wherein the temporary sheath is positioned by restraining the catheter shaft while the temporary sheath is advanced towards the balloon distal end,

wherein the advancing step includes depressing a flared end of the temporary sheath so as to avoid shifting of balloon material while the temporary sheath is being advanced towards the distal balloon end.

2. (canceled)

9. A method for assembling a medical device, comprising:

providing a catheter including a polymer scaffold crimped to a balloon, wherein the scaffold is configured for being plastically deformed by the balloon when the balloon; and

constraining the scaffold including placing a first sheath over the scaffold;

removing the first sheath from the scaffold; and

after removal of the first sheath, placing a second sheath over the scaffold;

wherein only after the second sheath is removed is the scaffold configured to be passed through the body.

10. The method of claim 9, wherein the second sheath

extends distally of a catheter distal end by about a length equal to the length of the scaffold.

11. (canceled)

13. The method of claim 9, wherein the second sheath includes

a protecting portion disposed over the scaffold, the protecting portion including an extension that is distal of a catheter distal end;

and

a constraining portion disposed over the scaffold and the protecting portion and applying a radial-inward force on the scaffold.

12. The method of claim 13, wherein the protecting sheath includes a first and second separable half disposed between the scaffold and the constraining sheath.

13-19. -19. (canceled)

21-24. -24. (canceled)

25. A method for making a medical device, comprising:

providing a scaffold formed from a tube and having a pre-crimp diameter, the tube comprising a polymer;

crimping the scaffold to a balloon catheter, the scaffold being crimped from the pre-crimp diameter to a final diameter, the pre-crimp diameter being at least 2 times the final diameter;

placing the crimped scaffold within a first sheath, the first sheath having a first diameter prior to placing over the crimped scaffold and a first radial stiffness sufficient to restrain recoil of the crimped scaffold;

replacing the first sheath with a second sheath having a second diameter prior to placing over the crimped scaffold and a second radial stiffness;

wherein the crimped scaffold is configured for being placed within a body only after the second sheath is removed from the crimped scaffold; and

wherein the first diameter is less than the second diameter and/or the first radial stiffness is greater than the second radial stiffness.