System for incising leaflets of a heart valve

A cutting system for use prior to valve replacement, the cutting system comprising:

• a cutting assembly that includes
• an expansion member that is movable between a stowed position and an expanded position, wherein the expansion member includes a slot defined therein,
• at least a first cutting member associated with the expansion member, wherein the first cutting member is movable radially outwardly with respect to the expansion member between a non-cutting position and a cutting position, wherein in the non-cutting position a cutting edge of the cutting member is located inboard of an outer surface of the expansion member and in the cutting position the cutting edge is located outboard of the outer surface of the expansion member, when the expansion member is in the expanded position, the first cutting member is movable radially outwardly through the slot between the non-cutting position and the cutting position, such that the cutting edge is located outboard of the outer surface of the expansion member, and when the expansion member is in the expanded position, the first cutting member is movable axially within the slot between a first cutting position and a second cutting position when the cutting edge is located outboard of the outer surface of the expansion member, and
• a sheath that defines a lumen therethrough, wherein the cutting assembly is movable within the lumen.