Stent crimping tool and method of use

Abstract

A tool and method for enabling substantially uniform and tight crimping of an intravascular stent onto a balloon catheter assembly. The crimping tool is constructed from a rigid cylindrical chassis sealed at both ends, having a hollow interior containing an elastic tube that partially occupies the interior. A piston abuts the elastic tube and forms a hermetically sealed chamber behind the piston and a closed end ofthe chassis. A port connected to an indeflator and positioned on the chassis provides an inlet into and out of the chamber. A stent that is loaded onto the balloon portion of the catheter is inserted through a central opening in another end of the chassis to position the stent catheter assembly within the axial space inside the elastic tube. The indeflator injects a fluid into the chamber thereby increasing its pressure which in turn displaces the piston into the elastic tube compressing the tube longitudinally. The elastic tube decreases in length and expands in thickness radially to crimp the stent onto the balloon catheter. Once pressure is relieved from the chamber, the piston moves away from the elastic tube, which restores to its original shape. The crimped stent and catheter can then be withdrawn. The piston may be driven by a power screw in place of fluid pressure.