US Patent 11766539 Enhanced flexibility neurovascular catheter

A catheter is provided comprising localized regions of modified flexibility. The regions of modified flexibility may comprise a softened inner liner, for example softened via stretching the inner liner or disposing a plurality of holes in the inner liner, to modify the bending stiffness and/or tensile stiffness of the catheter. The catheter may further include an axially extending filament that at least partially overlaps the softened portion of the inner liner. The axially extending filament may include an anchoring section to anchor the at least one axially extending filament in a section of the catheter that includes the helical coil.