Crush recoverable polymer scaffolds

Patent metadata

Field	Value
Publication number	US-9907685-B2
Application number	US-201314050283-A
Country	US
Kind code	B2
Filing date	Oct 9, 2013
Priority date	Jan 30, 2010
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

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 has a pattern including an asymmetric closed cell connecting links connecting the closed cells.

First claim

What is claimed is:

1. An implantable medical device, comprising:
a scaffold formed from a polymer tube
configured for being crimped to a balloon catheter,
the scaffold having a pattern of interconnected elements comprising struts and links, wherein an aspect ratio (AR) of the width to wall thickness of a strut or link is between 0.4 and 1.4, and
the scaffold having an expanded diameter when plastically deformed from a crimped state by the balloon of the catheter,

wherein the scaffold attains greater than 90% of the expanded diameter after being crushed by an amount equal to at least 33% of the expanded diameter for a crush duration of between 0 and 5 minutes.

2. The medical device of claim 1 , wherein a ratio of a pre-crimp scaffold diameter or a tube diameter to a scaffold wall thickness is between 30 and 60.

3. The medical device of claim 2 , wherein the pre-crimp scaffold diameter is 7-10 mm and the scaffold wall thickness is between 0.008″ and 0.014″.

4. The medical device of claim 2 , wherein the pre-crimp scaffold diameter is 7 mm, 8 mm or 9 mm.

5. The medical device of claim 1 , wherein the struts are curved struts.

6. An implantable medical device, comprising:
a scaffold formed from a polymer tube
configured for being crimped to a balloon catheter,
the scaffold having a pattern of interconnected elements, and
the scaffold having an expanded diameter when plastically deformed from a crimped state by the balloon of the catheter,

wherein the scaffold attains greater than 90% of the expanded diameter after being crushed by an amount equal to at least 33% of the expanded diameter for a crush duration of between 0 and 5 minutes, and
wherein the tube has a diameter, the tube diameter is a pre-crimp diameter for the scaffold (SDPC) and SDPC and the expanded diameter (SDI) are related by the inequality 1.1×(SDI)×(1/1.2)≦SDPC≦1.7×(SDI)×(1/1.2).

7. The medical device of claim 6 , wherein SDPC is between 6 mm and 12 mm.

8. The medical device of claim 6 , wherein a ratio of to a scaffold wall thickness is between 30 and 60.

9. The medical device of claim 8 , wherein the ratio of the to the scaffold wall thickness is between 30 and 45.

10. The medical device of claim 6 , wherein the interconnected elements comprise struts and links, and wherein an aspect ratio (AR) of the width to wall thickness of a strut or link is between 0.4 and 1.4.

11. The medical device of claim 6 , wherein when the scaffold has the expanded diameter the scaffold has a radial stiffness greater than 0.3 N/mm 2 .

12. The medical device of claim 6 , wherein the expanded diameter is a post-dilation diameter for the balloon, which is greater than a nominal diameter for the balloon.

13. An implantable medical device, comprising:
a scaffold formed from a polymer tube
configured for being crimped to a balloon catheter,
the scaffold having a pattern of interconnected elements, and
the scaffold having an expanded diameter when plastically deformed from a crimped state by the balloon of the catheter,

wherein the scaffold attains greater than 90% of the expanded diameter after being crushed by an amount equal to at least 33% of the expanded diameter for a crush duration of between 0 and 5 minutes, and
wherein when the scaffold has the expanded diameter the scaffold has a radial stiffness of between 0.3 N/mm 2 and 0.7 N/mm 2 .

14. A medical device, comprising:
a scaffold crimped to a balloon catheter, the scaffold
having a pre-crimp diameter 300-400% greater than a crimped diameter,
having an expanded diameter between 6 mm and 12 mm, and
adapted for being plastically deformed by a balloon of the catheter, whereby the scaffold attains the expanded diameter, and

wherein the plastically deformed scaffold is capable of regaining more than 90% of a plastically deformed scaffold diameter after being crushed to at least 75% of the plastically deformed scaffold diameter for a crush duration of between 0 and 5 minutes.

15. The medical device of claim 14 , wherein the scaffold has a ratio of the pre-crimp diameter to a wall thickness of between 30 and 60.

16. The medical device of claim 15 , wherein
the scaffold is crushed down to at least 75% of the plastically deformed scaffold diameter by crushing the scaffold between a pair of opposed flat metal plates,
the scaffold has a temperature of 20 degrees Celsius while being crushed between the plates, and
the scaffold attaining the greater than 90% of the expanded diameter is measured after a crush period of about 0 seconds, 1 minute or 5 minutes.

17. The medical device of claim 14 , wherein the scaffold has a ratio of the pre-crimp diameter to a wall thickness of between 20 and 45.

18. The medical device of claim 14 , wherein when the scaffold has the expanded diameter the scaffold has a radial stiffness greater than 0.3 N/mm 2 .

19. The medical device of claim 14 , wherein the plastically deformed scaffold is capable of regaining more than 80% of the plastically deformed scaffold diameter after being crushed by an amount equal to 50% of the plastically deformed scaffold diameter, and the scaffold has a wall thickness of between 0.008 inches and 0.011 inches.

20. An implantable medical device, comprising:
a crimped scaffold that when plastically deformed by a balloon forms a scaffold having an expanded diameter, wherein
the scaffold regains more than 80% of the expanded diameter after being crushed by an amount equal to 30% of the expanded diameter for a crush duration of between 0 and 5 minutes,
the scaffold has a pre-crimp diameter of between 6 and 12 mm,
the scaffold has struts and links, wherein a strut and/or link has a width to thickness ratio of between 0.4 and 1.4, and
wherein a ratio of a pre-crimp diameter of the scaffold to a scaffold wall thickness is between 20 and 45.

21. The medical device of claim 20 , wherein the ratio of the pre-crimp diameter of the scaffold to the scaffold wall thickness is 30 and 45.

22. The medical device of claim 20 , wherein the expanded diameter is an inflated diameter (SDI) for the scaffold on the balloon, and wherein the pre-crimp diameter (SDPC) and SDI are related by the inequality 1.1×(SDI)×(1/1.2)≦SDPC≦1.7×(SDI)×(1/1.2).

23. The medical device of claim 20 , wherein the scaffold comprises PCL or PEG.

Assignees

• Abbott Cardiovascular Systems Inc

Inventors

• Trollsas Mikael
• Ngo Michael H
• Anukhin Boris
• Hossainy Syed

Classifications

• B29L2031/7543

  Balloon catheters · CPC title

• Y10T29/49927

  Hollow body is axially joined cup or tube · CPC title

• A61F2002/91566

  connected trough to trough · CPC title

• A61F2/86

  Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure · CPC title

• A61F2/9522

  Means for mounting a stent or stent-graft onto or into a placement instrument · CPC title