REMOVABLE SHEATH ASSEMBLY FOR A POLYMER SCAFFOLD

• US 20140379065A1
• 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: Johnson, Mark C., Liu, Annie P., Anderson-Bolden, Erika Danielle
• Granted Patent: US 9,788,983 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 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2/962 having an outer sleeve
• 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 2002/9665 with additional retaining means
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: A61M 2025/1081 having sheaths or the like for covering the balloon but not forming a permanent part of the balloon, e.g. retractable, dissolvable or tearable sheaths
• CPC Class Codes: A61M 2025/1084 having features for increasing the shape stability, the reproducibility or for limiting expansion, e.g. containments, wrapped around fibres, yarns or strands
• CPC Class Codes: A61M 25/0009 Making of catheters or other medical or surgical tubes

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 balloon catheter having a distal end;

a scaffold crimped to the balloon, the scaffold having a length; and

a sheath disposed over the scaffold, the sheath having a distal end that extends beyond the catheter distal end by at least about the scaffold length;

wherein the apparatus is configured for being passed through a mammalian body only after the sheath is removed.

2. The apparatus of claim 1, wherein the sheath includes a protecting portion and a constraining portion, and wherein the protecting portion extends beyond the catheter distal end by at least about the scaffold length;

3. The apparatus of claim 2, wherein the both the constraining portion and the protecting portion extend beyond the catheter distal end by at least about the scaffold length.

4. The apparatus of claim 1, wherein the sheath includes a protecting sheath and a constraining sheath, and wherein a distal end of the protecting sheath abuts an inner surface of the constraining sheath when the constraining sheath is displaced towards the catheter distal end, whereupon both the protecting portion and the constraining portion are removed at the same time.

5. The apparatus of claim 1, 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 a starting or pre-crimp diameter to the crimped diameter that is at least 2-3 times reduced from its starting diameter.

6. The apparatus of claim 5, wherein the scaffold is made from a polymer composition comprising PLLA.

7. The device of claim 1, 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%.

8. The apparatus of claim 7, wherein the sheath applies a radial compressive force on the scaffold to limit recoil of the scaffold prior to use.

13. The apparatus of claim 1, wherein the constraining sheath includes a first and second inner diameter, the second diameter being greater than the first diameter.

14. The apparatus of claim 13, wherein the constraining sheath has a cylindrical portion forming the second diameter.

15. The apparatus of claim 14, wherein the cylindrical portion has a length about equal to a length of the scaffold.

9. An apparatus, comprising:

a balloon catheter having a distal end;

a scaffold crimped to the balloon; and

a sheath disposed over the scaffold and including a constraining sheath and a protecting sheath, wherein the constraining sheath and the protecting sheath extend beyond the catheter distal end;

wherein the apparatus is configured for being passed through a mammalian body only after the constraining and protecting sheaths are removed.

10. The apparatus of claim 9, wherein the constraining sheath includes a first tube attached to a second tube, the first tube having a first diameter and the second tube having a second diameter greater than the first diameter.

11. The apparatus of claim 9, wherein the constraining sheath and the protecting sheath are about equal in length.

12. The apparatus of claim 9, wherein the protecting portion includes a portion having split halves held together when the constraining sheath is disposed over the protecting sheath.

16. An apparatus, comprising:

a balloon catheter;

a scaffold crimped to the balloon;

a protecting sheath disposed over the scaffold; and

a constraining sheath disposed over the protecting sheath, the constraining sheath including a first portion configured to apply a radial constraining force on the scaffold and a second portion configured to not apply a radial compressive force on the scaffold, wherein a length of the first and second portions are about the same or the second portion length is greater than the first portion length; and

wherein the apparatus is configured for being passed through a mammalian body only after the constraining sheath and protecting sheath are removed.

17. The apparatus of claim 16, wherein the first portion has an inner diameter less than an inner diameter of the second portion.

18. The apparatus of claim 16, wherein the protecting portion includes a slit extending over at least a portion of the protecting portion, wherein the length of the first portion is about the length of the portion.

19. The apparatus of claim 16, wherein the protecting sheath has a third portion including a slit and a fourth portion devoid of the slit, and wherein the first portion is about the length of the third portion and the second portion is about the length of, or less or greater than the length of the fourth portion.

20. The apparatus of claim 16, wherein the first portion comprises a first tube and the second portion comprises a second tube connected to the first tube.