Deep vein thrombosis (DVT) refers to a blood clot that forms in a vein deep in the body, most frequently in the lower leg or thigh. While the clot sometimes will cause no symptoms in the person who has it, the clot or part of it may dislodge and travel to other areas of the body, especially the lung, where it may block an artery. This type of blockage is known as a pulmonary embolism. Stroke and heart attack are other potential consequences if the clot lodges in the brain or heart. According to the Surgeon General, between 350,000 and 600,000 Americans develop DVT or a pulmonary embolism each year. Together, they contribute to at least 100,000 deaths a year.
Basically, any activity that requires you to stay in a certain position for a long period of time adds to the risk of DVT.
DVT may be a silent condition or it may cause pain, swelling or discoloration of the skin near the clot site. There are many factors that place people at increased risk of contracting DVT. A few of these are prolonged bed rest, recent surgery, long trips in a plane or car, pregnancy and jobs that require long uninterrupted periods of sitting. Basically, any activity that requires you to stay in a certain position for a long period of time adds to the risk of DVT. Taking breaks where you change your position, such as walking the aisle during a flight, is usually helpful.
The study was performed at Emory University School of Medicine, using 37 patients, 16 of whom had DVT and 21 of whom had an arterial clot. All received the clot-busting drug tPA (tissue plasminogen activator), along with an ultrasound treatment. The combined treatment dissolved all the arterial clots and 10 of the 16 venous clots completely. Four of the other six DVT patients had their clots partially dissolved and two showed no benefit from the treatment. One patient suffered a complication, a neck hematoma, from the treatment. The results of the study were presented November 23, 2008 at the annual VEITH symposium in New York City.
More information on DVT is available from The Agency for Healthcare Research and Quality (AHRQ), a part of the U.S. Department of Health by searching the term "blood clot" at http://www.ahrq.gov/.