A medical device assembly for incising a stenosis in a blood vessel which includes an incising device, a tubular sheath, and a catheter having an inflatable balloon mounted thereon. The incising device includes a self-expanding scaffold having a plurality of cutting elements projecting radially outward therefrom, and an elongate member extending proximally from the self-expanding scaffold to be manipulated by a user. The self-expanding scaffold is positionable in the lumen of the sheath in a contracted configuration and deployed out of the lumen of the sheath to permit the self-expanding scaffold to expand to an expanded configuration. The inflatable balloon of the catheter is configured to be advanced distally into an interior of the self-expanding scaffold through a proximal opening of the self-expanding scaffold, and inflation of the inflatable balloon urges the cutting elements radially outward to incise a stenosis.
