Reducing crimping damage to a polymer scaffold

摘要

A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. The scaffold is crimped to the catheter by a multi-step process for increasing scaffold-catheter yield following a crimping sequence. Damage reduction during a crimping sequence includes modifying blades of a crimper, adopting a multi-step crimping sequence, and inflating a supporting balloon to support the scaffold during crimping.

主权项

1. A method for crimping a polymer scaffold to a balloon using a crimping device that has a plurality of movable blades, each blade having a tip, the tips arranged to collectively form an iris about a rotational axis thereof, the iris defining a crimp aperture about which the movable blades are disposed, a first and second sheet of polymer film extending between a first and second pair of blades such that a portion of the first and second sheets extends across the aperture, the method including the steps of:
placing the scaffold on the balloon; disposing the scaffold and balloon in the aperture such that the scaffold and balloon are located between the first and second sheet portions; inflating the balloon; and displacing the plurality of movable blades from a first diameter to a second diameter; wherein a balloon pressure is adjusted as a diameter of the scaffold is reduced by the blades such that a radially directed outward pressure applied on the scaffold by the balloon supports the scaffold to avoid or compensate for irregular bending or twisting of scaffold structure.