The intravascular administration of thrombolytic agents originated in the 1960s with the intravenous (IV) treatment of pulmonary embolism. Thrombolysis by means of selective catheter infusion for vascular occlusion entered the mainstream during the 1970s. Since then, techniques for thrombolysis have branched in several directions with the treatment of thrombus and/or thrombosis in the coronary arteries, peripheral vascular and visceral arteries, dialysis grafts, veins, and IV catheters.