Patent ID: 8920450

Claim:
A material removal device for cutting material from the lumen of a vessel comprising: a first drive shaft having proximal and distal ends and being configured to rotate in a first direction; a second drive shaft having proximal and distal ends and being configured to rotate in a second direction; a first cutting element at the distal end of the first drive shaft configured for rotation about a first rotational axis, the first cutting element having a distal end, an opening extending proximally through the distal end of the first cutting element, and annular cutting edge at the distal end of the first cutting element for cutting material in the lumen of the vessel; and a second cutting element at the distal end of the second drive shaft configured for rotation about a second rotational axis, the second cutting element having a conical distal portion tapering distally toward the second rotational axis to a distal tip of the second cutting element, wherein the second cutting element is received in the opening of the first cutting element and is configured for boring through a material in the lumen of the vessel, wherein the second cutting element has flutes extending along an exterior surface of the second cutting element to allow material which is cut to pass proximally therethrough, wherein the first cutting element has flutes extending along an interior surface defining the opening of the first cutting element to allow material which is cut to pass proximally therethrough, and wherein the respective flutes of the first and second cutting elements are configured to cooperate with one another to shear removed material as the first and second cutting elements rotate relative to one another.