Crush recoverable polymer scaffolds having a low crossing profile

• US 8,808,353 B2
• Filed: 01/27/2011
• Issued: 08/19/2014
• Est. Priority Date: 01/30/2010
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Anukhin, Boris, Ngo, Michael H., Trollsas, Mikael, Hossainy, Syed, Papp, John E.
• Primary Examiner(s): Sweet, Thomas J
• Assistant Examiner(s): PRESTON, REBECCA STRASZHEIM
• Application Number:
  US13/015,474
• Publication Number:
  US 20110190872A1
• Time in Patent Office: 1,300 Days
• Field of Search: 623/1.18
• US Class Current: 623/1.18
• 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 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2240/002 Designing or making customized prostheses
• CPC Class Codes: A61M 25/1034 Joining of shaft and balloon
• CPC Class Codes: B23P 11/005 by expanding or crimping
• CPC Class Codes: B29C 55/24 radial
• CPC Class Codes: B29C 69/00 Combinations of shaping techniques not provided for in a single one of main groups B29C39/00 - B29C67/00, e.g. associations of moulding and joining techniques; Apparatus therefore B29C48/001 takes precedence
• CPC Class Codes: Y10T 29/49908 Joining by deforming

Abstract

A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. The scaffold, after being deployed by the balloon, provides a crush recovery of about 90% after the diameter of the scaffold has been pinched or crushed by 50%. The scaffold also has a reduced crimped profile and a modification of the scaffold'"'"'s ring structure at the crowns that contributes to the reduced crimped profile.

Claims

1. A medical device implantable within a peripheral vessel of the body, comprising:

a scaffold formed from a polymer tube

configured for being crimped to a balloon,

the scaffold having a wall thickness of between 0.008″ and

0.0014″

,

the scaffold having a pre-crimp diameter of between 7 mm and 10 mm,

the scaffold having a pattern of interconnected elements and

the scaffold having an expanded diameter when plastically deformed from a crimped state by inflation of the balloon,

wherein the scaffold attains at least 90% of its expanded diameter after being crushed to at least 75% of its expanded diameter for a crush duration of 0 to 5 minutes.

2. The medical device of claim 1, wherein the scaffold attains greater than 80% of its expanded diameter after being crushed to 50% of its expanded diameter for a crush duration of 0 to 5 minutes.

3. The medical device of claim 2, wherein

the scaffold is crushed using a pair of opposed flat metal plates,

the duration of crush is approximately 0 seconds, 1 minute or 5 minutes, and

the scaffold has a temperature of 20 degrees Celsius during the crush.

4. The medical device of claim 3, wherein the scaffold is formed from a PLLA tube.

5. The medical device of claim 2, wherein the interconnected elements include a plurality of rings and a plurality of links connecting each ring to at least one other ring,

wherein the interconnected elements form a plurality of closed cells, wherein a closed cell is connected to adjacent closed cells by a portion of the plurality of links,

wherein each ring includes a plurality of crowns each having a maximum crown angle of between 90 degrees and 115 degrees when the scaffold has the expanded diameter, and

wherein the closed cell is symmetric about two orthogonal axes with respect to the portion of the plurality links connecting the closed cell to the adjacent closed cells.

6. The medical device of claim 1, wherein the interconnected elements include rings having crowns, and wherein a crown has an inner radius of about 0 inches.

7. The medical device of claim 1, wherein the scaffold is cut from a tube having the pre-crimp diameter between (1.7)*(SD_I)*(1.2)⁻

1 and (1.0*(8130*(1.2)<sup>−

1</sup>, where SD_I is the expanded diameter.

8. The medical device of claim 7, wherein the expanded diameter (SD_I) is between 6 mm and 12 mm.

9. A medical device for being implanted within a peripheral vessel of the body, comprising:

a scaffold formed from a polymer tube

crimped to a balloon,

the scaffold having interconnected elements and

the scaffold having an expanded diameter when plastically deformed from a crimped state by inflation of the balloon;

wherein the scaffold attains greater than 80% of its expanded diameter after being crushed to 50% of its expanded diameter for a crush duration of between 0 and 5 minutes; and

wherein the crimped scaffold has a crimped diameter of about equal to or less than a theoretical minimum diameter for the crimped scaffold; and

wherein the interconnected elements include a plurality of crowns, each having a maximum crown angle of between 90 degrees and 115 degrees when the scaffold has the expanded diameter.

10. A medical device, comprising:

a polymer scaffold crimped to a balloon and when plastically deformed by the balloon the scaffold attains an expanded diameter;

wherein the crimped scaffold has a pattern of interconnected elements, the interconnected elements including

a plurality of rings and a plurality of links connecting each ring to at least one other ring, and

a plurality of closed cells, wherein a closed cell is connected to adjacent closed cells by a portion of the plurality of links,

wherein the closed cell is symmetric about two orthogonal axes with respect to the portion of the plurality links connecting the closed cell to the adjacent closed cells; and

wherein the scaffold is capable of regaining more than 80% of its expanded diameter after being crushed to 50% of its expanded diameter for a crush duration of between 0 and 5 minutes.

11. The medical device of claim 10, wherein the scaffold is made from a tube comprising PLLA and wherein the tube is radially expanded such that the scaffold formed from the tube has a morphology comprising circumferentially orientated polymer chains.

12. The medical device of claim 10, wherein the scaffold expanded diameter is equal to, or greater than 6 mm, and the scaffold has a wall thickness of greater than 0.008 inches.

13. A medical device implantable within a peripheral vessel of the body, comprising:

a scaffold formed from a polymer tube

crimped to a balloon,

the scaffold having interconnected elements, and

the scaffold having a diameter when plastically deformed from a crimped state by inflation of the balloon to at least a nominal diameter of the balloon;

wherein the plastically deformed scaffold attains greater than 80% of the plastically deformed diameter after being crushed to at least 75% of the plastically deformed diameter for a crush duration of between 0 and 5 minutes; and

wherein the interconnected elements include a plurality of crowns, each having a maximum crown angle of between 90 degrees and 115 degrees when the scaffold has the plastically deformed diameter.

14. The medical device of claim 13, wherein the scaffold attains greater than 80% of the plastically deformed diameter after being crushed to 50% of the plastically deformed diameter for a crush duration of between 0 and 5 minutes.

15. The medical device of claim 13, wherein the scaffold attains greater than 90% of the plastically deformed diameter after being crushed to at least 75% of the plastically deformed diameter for a crush duration of between 0 and 5 minutes.

16. The medical device of claim 13, wherein the scaffold is cut from a tube having a tube diameter that is between 0.92 and 1.4 times the inflated diameter.

17. The medical device of claim 13, wherein

the scaffold is crushed using a pair of opposed flat metal plates,

the duration of crush is approximately 0 seconds, 1 minute or 5 minutes, and

the scaffold has a temperature of 20 degrees Celsius during the crush.