Polymer scaffolds for peripheral vessels

• US 9,498,359 B2
• Filed: 07/13/2012
• Issued: 11/22/2016
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Eli, Erik David, Ngo, Michael Huy, Trollsas, Mikael, Hossainy, Syed, Smith, Joshua Takeshi, Davalian, Dariush
• Primary Examiner(s): Prone, Christopher D
• Assistant Examiner(s): Diop, Rokhaya
• Application Number:
  US13/549,366
• Publication Number:
  US 20140018903A1
• Time in Patent Office: 1,593 Days
• Field of Search: 623/1.1, 623/1.12, 623/1.14, 623/1.15, 623/1.16
• US Class Current: 1/1
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. The scaffold has a structure that produces a low late lumen loss when implanted within a peripheral vessel and also exhibits a high axial fatigue life. In a preferred embodiment the scaffold forms ring structures interconnected by links, where a ring has 12 crowns and at most two links connecting adjacent rings.

Claims

1. A medical device, comprising:

a scaffold crimped to a balloon;

the scaffold forming a network of rings interconnected by links, including

12 crests and 12 troughs per ring,

each ring having a plurality of U crowns, Y crowns and W crowns,

the rings including a first ring, a second ring adjacent the first ring, a third ring adjacent the second ring, and a fourth ring adjacent the third ring,

the first ring is connected to the second ring by at most two links, each of which being connected to the first ring at a W crown and the second ring at a Y crown and such that there are an equal number of U crowns on each side of the W crown of the first ring and each side of the Y crown of the second ring,

the second ring is connected to the third ring by at most two links, each of which being connected to the second ring at a W crown and the third ring at a Y crown and such that there are an equal number of U crowns on each side of the W crown of the second ring and each side of the Y crown of the third ring,

the third ring is connected to the fourth ring by at most two links, each of which being connected to the third ring at a W crown and the fourth ring at a Y crown and such that there are an equal number of U crowns on each side of the W crown of the third ring and each side of the Y crown of the fourth ring, and

wherein the scaffold has a wall thickness of between 0.203 mm and 0.356 mm and a pre-crimp diameter between 7 mm and 9 mm, and

wherein

the balloon has a nominal inflation diameter,

the scaffold attains a plastically deformed state when the balloon is inflated to the nominal inflation diameter, whereupon the scaffold has an expanded diameter, and

the scaffold attains about 80% of the expanded diameter after being crushed to over 50% of the expanded diameter.

2. The device of claim 1, where the scaffold is made from poly (L-lactide (PLLA) or a copolymer of PLLA and polycaprolactone (PCL).

3. The device of claim 1, wherein the balloon has a nominal inflation diameter of 6 mm.

4. The device of claim 1, wherein an aspect ratio (AR) of a strut width of a strut of a ring to the wall thickness is about 0.7.

5. The device of claim 1, wherein an aspect ratio (AR) of a link width to the wall thickness is about 0.7.

6. The device of claim 1, wherein the scaffold is characterized by

(1) radially aligned polymer chains resulting from a biaxial expansion of a precursor tube that was formed into the scaffold, and

(2) the scaffold was crimped from the pre-crimp diameter to a diameter that is at least 2-3 times reduced from the pre-crimp diameter.

7. The device of claim 6, wherein the scaffold is made from PLLA.

8. The device of claim 6, wherein the polymer chains of the scaffold are aligned in a radial direction resulting from a radial draw percentage of between about 400% and 450%.

9. The device of claim 1, wherein the scaffold attains over 90% of its diameter after being crushed to 50% of its diameter.

10. The device of claim 1, wherein the scaffold is formed from a biaxially expanded polymer tube.

11. The device of claim 10, wherein the scaffold has a semi-crystalline structure resulting from a process where an extruded precursor tube is radially expanded using a radial draw ratio of over 400% to produce the radially expanded tube from which the scaffold was made.

12. The medical device of claim 1, wherein each of the links has a longitudinal axis and extends parallel to a longitudinal axis of the scaffold, and wherein each of the links connecting the first ring to the second ring is co-linear with a respective one of the links connecting the third ring to the fourth ring.

13. A medical device, comprising:

a scaffold crimped to a balloon having a nominal inflation diameter;

the scaffold having a longitudinal axis and forming a network of rings interconnected by links, including

8 to 12 crests and 8 to 12 troughs, respectively per ring,

each ring having a plurality of U crowns, Y crowns and W crowns,

the rings including a first ring, a second ring adjacent the first ring, a third ring adjacent the second ring, and a fourth ring adjacent the third ring,

the first ring is connected to the second ring by at most two links, each of which being connected to the first ring at a W crown and the second ring at a Y crown and such that there are an equal number of U crowns on each side of the W crown of the first ring and each side of the Y crown of the second ring,

the second ring is connected to the third ring by at most two links, each of which being connected to the second ring at a W crown and the third ring at a Y crown and such that there are an equal number of U crowns on each side of the W crown of the second ring and each side of the Y crown of the third ring, and

the third ring is connected to the fourth ring by at most two links, each of which being connected to the third ring at a W crown and the fourth ring at a Y crown and such that there are an equal number of U crowns on each side of the W crown of the third ring and each side of the Y crown of the fourth ring,

wherein each of the links has a longitudinal axis and extends parallel to the longitudinal axis of the scaffold, and wherein each of the links connecting the first ring to the second ring is co-linear with a respective one of the links connecting the third ring to the fourth ring, and

wherein the scaffold further includes

a wall thickness of between 0.203 mm and 0.356 mm,

a pre-crimp diameter of between 7 mm and 9 mm, and

a pre-crimp diameter greater than or equal to the nominal inflation diameter.