Posted by R Chang MD on January 10, 19102 at 13:54:53:
In Reply to: Re: Blood clot posted by michael rawls on October 27, 19101 at 11:05:50:
Current treatment for deep vein thrombosis is anticoagulation -ususally low molecular weight heparins and then conversion to oral warfarin. This type of therapy is very good for preventing a blood clot from breaking off and going to the lung, and probably does a pretty good job of preventing growth of the blood clot in the leg.Unfortunately, most articles extolling the virtues of this therapy do not address what happens to the clot that has already formed in the veins of the leg that caused the problem in the first place. It turns out that if you focus on this aspect of the problem, anticoagulation is a very poor treatment Annals Internal Medicine 1980; 93-141-144. Clot dissolution on anticoagulants alone is often so slow, thateven when the clots finally dissolve (over months) the valves are ususally damaged, and the patient has chronic symptoms and phlebitis.
Thrombolytic therapy is very effective provided treatment is done when the clot is still fresh-usually first 2 weeks. Many articles which say it is not effective and highly dangerous are based on older methods: giving large doses of thrombolytic enzyme intravenously. Today the thrombolytic enzyme is selectively injected into the clot instead of relying on diffusion allowing doctors to use smaller and safer doses more effectively. However, thrombolytic therapy works well only when the clot is fresh. If one waits a month after diagnosis, the clot becomes much more resistant to thrombolysis, and at 3 months, thrombolytic therapy is probably not even worth trying in Venous thrombosis.So there is a narrow window of oppurtunity where we can dissolve blood clot quickly,try to preserve the venous valves, and prevent chronic problems to maintain quality of life. We have a research protocol for treating fresh deep vein thrombosis of the leg at NIH-protocol#98-CC-0067.
If anticoagulation fails to restore the venous function, the patient has symptoms of chronic venous insufficiency. Current advice is to elevate leg whenever possible, remain active to keep blood moving, support stockings, and when at rest some use pneumatic compression devices to keep flow and reduce risk of rethrombosis. Some patients may even need lifelong antoicoagulation. There is research on development of prosthetic valves to replace damaged valves,but none are available yet. Bypass and interposition or transplant of a vein segment from one part of the body to replace a defective one requires a superspecialist- a vascular surgeon who specializes in these problems if you wnt the bestb results. Unfortunately, like many problems prevention is the best treatment for some patients. A more aggressive treatment than anticoagulation may be able to prevent progression of acute DVT to Chronic DVT that impacts the Quality of life.