This rare procedure is used to clean out clogged heart arteries. A DCA catheter has a hollow cylinder on the tip with an open window on one side and a balloon on the other. When the catheter is inserted into the narrowed artery, the balloon is inflated, pushing the window against the fatty matter clogging the vessel. A blade (cutter) within the cylinder rotates and shaves off any fat, which protruded into the window. The shavings are caught in a chamber within the catheter and removed. This process is repeated as needed to allow better blood flow.