US Patent 10183146 Method of making an enhanced flexibility neurovascular catheter

A method of making a high flexibility distal zone on a neurovascular catheter is provided. The method includes the steps of dip coating a removable mandrel to form a tubular inner layer on the mandrel, coating the tubular inner layer with a soft tie layer, applying a helical coil to the outside of the tie layer, positioning a plurality of tubular segments on the helical coil, heating the tubular segments to form the high flexibility distal zone on the neurovascular catheter; and removing the mandrel. The plurality of segments have durometers that decrease in a distal direction. The flexural load profile of the catheter as a function of catheter length is configured to provide enhanced distal flexibility while maintaining high backup support.