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US 8,261,423 B2Granted
Methods for crimping a polymeric stent onto a delivery balloon
AssigneeAbbott Cardiovascular Systems Inc.
InventorsKevin F. Jow, Arlene Sucy Yang, Yunbing Wang, Kathleen W. Yan
Life of this patent
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Abstract
A medical device-includes a polymer stent crimped to a catheter having an expansion balloon. The stent is crimped to the balloon by a process that includes heating the stent to a temperature below the polymer's glass transition temperature to improve stent retention without adversely affecting the mechanical characteristics of the stent when later deployed to support a body lumen.
Claims11
A method for crimping a balloon-expanded stent scaffolding to a balloon, comprising the steps of:
- providing a tube comprising PLLA-(Poly(L-lactide)) characterized by a glass transition temperature range having a lower limit of about 55° C.;
- radially expanding the tube to increase its radial stiffness;
- forming the scaffolding from the radially-expanded tube, including the steps of forming a circumferential series of closed cells having a W-shape and linear link struts connecting the W-shape cells;
- and
- crimping the scaffolding to the balloon while the scaffolding has a temperature of between about 48° C. and 54° C.;
- wherein in a first crimping step the scaffolding is crimped to a first diameter by placing a crimper head at a first diameter and holding the crimper head at the first diameter while the balloon is inflated to a first pressure.
3 more elements
A method for crimping a scaffolding to a balloon, comprising the steps of:
- providing the scaffolding from a radially-expanded tube comprising a polymer characterized by a glass transition temperature (Tg), the scaffolding having a pre-crimp scaffolding diameter;
- and
- crimping the scaffolding to the balloon while the scaffolding has a temperature of between about Tg-low and 15 degrees below Tg-low, including the steps of:
- raising the balloon pressure to increase the balloon diameter to about the pre-crimp scaffolding diameter, and
- crimping the scaffolding to a final crimp diameter while balloon pressure is being released.
2 more elements
Dependencies are inferred from the claim text.