Thrombolysis is a treatment offered to patients who have acute blood clot in their blood vessels. This treatment is designed to dissolve blood clots by the action of a drug called a plasminogen activator. Generally speaking, plasminogen activators, which are delivered into the blood clot through a catheter, act more effectively than if they are given by the general intravenous route. The plasminogen activator cleaves (splits) the bodyís plasminogen to convert it to plasmin, an enzyme that actively breaks down fibrin (the solid substance of the blood clot). Extensive deep venous thrombosis (clots in the deep veins of the leg) causing pain, swelling, and discoloration may result in the post-thrombotic syndrome (pain, swelling, skin discoloration, and, potentially, ulceration). The more extensive the deep venous thrombosis, the more severe the post-thrombotic syndrome will be. Over time, patients with extensive venous thrombosis are likely to develop progressive valvular incompetence. This is the inability of the vein valves to keep the blood from flowing backward (reflux) into the legs after it has started its journey back to the heart. When a valve isnít doing its job in preventing reflux, it is called incompetent. Eliminating the blood clot is likely to preserve function of the vein valves and of course eliminates the obstruction to venous return.

The earlier the treatment is begun after a patient develops a clot, the more likely it is that treatment will be successful. Generally, early treatment within 14 days of acute symptoms is successful, restores patency (open and unobstructed state) to the vein, and reduces the frequency and severity of the post-thrombotic symptoms.

Treatment objectives of thrombolysis are:

1. To prevent pulmonary embolism (clot in the lung)

2. To reduce or eliminate the acute symptoms of iliofemoral (pelvic and thigh) deep venous thrombosis

3. To reduce or avoid post-thrombotic syndrome