Polymer scaffold sheaths

• US 9,119,741 B2
• Filed: 03/21/2013
• Issued: 09/01/2015
• Est. Priority Date: 05/27/2011
• Status: Expired due to Fees

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Phillips, Jason, McNiven, Sean, Liu, Annie P, Johnson, Mark C
• Primary Examiner(s): BERDICHEVSKY, AARTI
• Application Number:
  US13/848,683
• Publication Number:
  US 20130218256A1
• Time in Patent Office: 894 Days
• Field of Search: 604/103.05, 604/160, 604/161, 623/1.11, 623/1.12, 623/1.23
• 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 2/9522 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: 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 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00
• CPC Class Codes: A61M 25/1036 Making parts for balloon catheter systems, e.g. shafts or distal ends A61M25/1029 takes precedence
• CPC Class Codes: Y10T 29/49865 by temperature differential [e.g., shrink fit]
• CPC Class Codes: Y10T 29/49913 by constricting outer annulus

Abstract

A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. A sheath pair 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 pair is removed by a health professional before placing the scaffold within the body.

Claims

1. An apparatus, comprising:

a catheter including a scaffold comprising a polymer crimped to a balloon;

a constraining sheath applying a radial inward force on the scaffold; and

a protecting sheath disposed between the scaffold and the constraining sheath, the protecting sheath including a step or notch configured to resist removal of the protecting sheath from the scaffold while the constraining sheath applies the radial force on the scaffold;

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

2. The apparatus of claim 1, wherein the step or notch is located at a proximal end of the protecting sheath.

3. The apparatus of claim 1, wherein the step or notch is formed by separable halves of the protecting sheath.

4. The apparatus of claim 1, wherein the protecting sheath is configured such that the separable halves are brought together to form the step or notch when the protecting sheath is disposed between the scaffold and the constraining sheath.

5. The apparatus of claim 1, wherein the constraining sheath has an inner diameter, the protecting sheath has a medial portion forming a first outer diameter, a distal end forming a second outer diameter and a proximal end forming a third outer diameter, and

the second and third outer diameters are greater than the constraining sheath inner diameter and the first outer diameter.

6. The apparatus of claim 1, wherein the protecting sheath includes an abutment having an extent capable of preventing the constraining sheath from being disposed proximally of the proximal end of the scaffold.

7. The apparatus of claim 1, wherein the constraining sheath applied radial force is such that a crossing profile is maintained, the scaffold is formed from a radially expanded tube and a ratio of the scaffold diameter before crimping to after crimping is 2:

1, 2.5;

1, 3;

1 or higher.

8. An apparatus, comprising:

a catheter including a scaffold comprising a polymer crimped to a balloon;

a constraining sheath applying a radial force on the crimped scaffold; and

a protecting sheath located between the constraining sheath and scaffold;

wherein the constraining sheath is located between ends of the protecting sheath; and

wherein the apparatus is configured for being passed through the body of a patient only after the constraining sheath and protecting sheath are removed, and

wherein the protecting sheath has a raised first end and a raised second end and the constraining sheath is between the raised first and second ends.

9. The apparatus of claim 8, wherein the protecting sheath has a length sufficient to enable the constraining sheath to be substantially removed from the scaffold while the constraining sheath remains on the protecting sheath.

10. The apparatus of claim 8, wherein the constraining sheath has a length at least equal to a length of the scaffold.

11. The apparatus of claim 8, wherein the protecting sheath has a length about twice the length of the scaffold.

12. The apparatus of claim 8, wherein the constraining sheath applied radial force is such that a crossing profile is maintained, the scaffold is formed from a radially expanded tube and a ratio of the scaffold diameter before crimping to after crimping is 2:

1, 2.5;

1, 3;

1 or higher.

13. An apparatus, comprising:

a catheter including a scaffold comprising a polymer crimped to a balloon;

a constraining sheath applying a radial inward force on the scaffold; and

a protecting sheath disposed between the scaffold and the constraining sheath;

wherein the constraining sheath has an inner diameter, the protecting sheath has a medial portion forming a first outer diameter, a distal end forming a second outer diameter and a proximal end forming a third outer diameter;

the second and third outer diameters are greater than the constraining sheath inner diameter and the first outer diameter; and

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

14. The apparatus of claim 13, wherein the protecting portion comprises separable halves.

15. The apparatus of claim 14, wherein the protecting sheath is configured such that the separable halves are brought together to form a step or notch when the protecting sheath is disposed between the scaffold and the constraining sheath.