Crush recoverable polymer scaffolds

• US 9,907,685 B2
• Filed: 10/09/2013
• Issued: 03/06/2018
• 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: Trollsas, Mikael, Ngo, Michael H., Anukhin, Boris, Hossainy, Syed
• Primary Examiner(s): Sharma, Yashita
• Assistant Examiner(s): PRESTON, REBECCA STRASZHEIM
• Application Number:
  US14/050,283
• Publication Number:
  US 20140039604A1
• Time in Patent Office: 1,609 Days
• Field of Search: None
• 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 2/844 folded prior to deployment
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/825 having longitudinal struts
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0096 Markers and sensors for detecting a position or changes of a position of an implant, e.g. RF sensors, ultrasound markers
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61L 27/00 : Materials for grafts or prostheses or for coating grafts or prostheses dental prostheses A61C13/00; shape or structure of prostheses A61F2/00; use of preparations for artificial teeth A61K6/80; artificial kidneys A61M1/14
• CPC Class Codes: A61L 31/06 : obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/14 : Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: B21D 39/046 : Connecting tubes to tube-like fittings
• CPC Class Codes: B29C 2035/0838 : using laser
• CPC Class Codes: B29C 35/08 : by wave energy or particle radiation B29C64/00, B29C71/04 take precedence
• CPC Class Codes: B29K 2067/046 : PLA, i.e. polylactic acid or polylactide
• CPC Class Codes: B29L 2023/00 : Tubular articles B29L2024/00 takes precedence ; catheters B29L2031/7542
• CPC Class Codes: B29L 2031/7543 : Balloon catheters
• CPC Class Codes: C08L 67/04 : Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C08L 71/02 : Polyalkylene oxides
• CPC Class Codes: Y10T 29/49826 : Assembling or joining
• CPC Class Codes: Y10T 29/4987 : Elastic joining of parts
• CPC Class Codes: Y10T 29/49908 : Joining by deforming
• CPC Class Codes: Y10T 29/49925 : Inward deformation of aperture or hollow body wall
• CPC Class Codes: Y10T 29/49927 : Hollow body is axially joined cup or tube

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.

Claims

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/mm².

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/mm² and 0.7 N/mm².

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/mm².

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.