Polymer Scaffolds Having Enhanced Axial Fatigue Properties
AssigneeAbbott Cardiovascular Systems Inc.
InventorsMichael Huy Ngo, Samit Mustafa, Syed Hossainy, Mikael Trollsas
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Abstract
A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. The scaffold has a morphology resulting from a biaxially expanded tube arranged to provide a more balanced, or less anisotropic axial and radial mechanical properties. The scaffold has improved mechanical properties suited for use as a balloon expandable scaffold implanted in a peripheral vessel of the body.
Claims15
A peripherally-implanted medical device, comprising:
- a balloon-expanded scaffold formed from a biaxially expanded polymer tube;
- the tube having a morphology comprising polymer chains having a preferred orientation resulting from a ratio of radial expansion to axial expansion of between about 2 and 1;
- the scaffold forming a network of rings interconnected by links, including 8 or 12, or between 8 and 12 crowns per ring, and
- at most 2 links connecting substantially all pairs of adjacent rings,
- wherein for any ring of the scaffold there are an equal number of unsupported crowns on each side of each crown connected to a link.
A method for making a peripherally-implanted scaffold, comprising:
- reducing a recoil of the scaffold by biaxially expanding a polymer tube according to a ratio RE/AE of between 400/200 and 200/200;
- and
- forming a scaffold from the biaxially-expanded tube, including forming a network of rings interconnected by links.
A method for making a peripherally-implanted scaffold, comprising:
- biaxially expanding a tube, wherein an amount of radial verses axial expansion of the tube is such that a ratio of an elongation at break in the radial direction and an elongation at break in the axial direction of the biaxially-expanded tube material is about 1, or less than 1;
- forming a scaffold from the biaxially-expanded tube, including forming a network of rings interconnected by links.
A peripherally-implanted medical device, comprising:
- a balloon-expanded scaffold formed from a biaxially expanded polymer tube, wherein the biaxially-expanded tube material has a ratio of a radial elongation at break and axial elongation at break of about 1, or less than 1;
- the scaffold forming a network of rings interconnected by links, including 8 or 12 crowns per ring, and
- at most 2 links connecting substantially all pairs of adjacent rings,
- wherein for any ring of the scaffold there are an equal number of unsupported crowns on each side of each crown connected to a link.
Dependencies are inferred from the claim text.