Transient targeted thromboprophylaxis (TTT) for prevention of postsurgical thrombosis. Thromboprophylaxis is especially problematic in the early postoperative period. Thrombosis is a common complication of the trauma, inflammation, and immobility that accompany surgery, and thrombi are prone to recur or extend within hours of fibrinolysis, necessitating protracted activity. However, the risk of bleeding may preclude intervention for hours to days. Fibrinolytics are not used for prophylaxis because they are rapidly inactivated and cleared from the blood, necessitating use of high and unsafe doses to maintain activity. A rapid transient intervention that spares hemostatic clots, but prevents subsequent development of occlusive thrombosis elsewhere would fill a clear void in clinical management. This is but one of many settings in which patients at known imminent risk of thrombosis would benefit from TTT. An ideal agent for TTT would have an immediate onset of action that is of sufficient duration to prevent occlusive thrombi from forming without affecting preexisting fresh hemostatic clots (eg, those formed in the wound within ∼20-30 minutes of uncomplicated surgery) and without causing off-target toxicity.