London (Reuters Health) - People who undergo major orthopedic surgery are advised not to travel long distances for up to three months after their operations because of the risk of deep vein thrombosis (DVT). DVT is a serious condition where blood clots develop in the deep veins of the legs. John Smith, chairman of the All-Party Group on Travel-Related DVT, warned that patients often go off on holiday to recover after hip or knee replacement, and are unaware of the risks of long flight.

A group of British Members of Parliament recommended that traveling for more than three hours triples the risk of DVT if the traveler has had recent surgery. They based their decision on a recent study of 568 patients attending Dr. Ander Cohen's (a vascular surgeon) clinic in King's College Hospital in London, England. A Scandinavian study published last year also found a highly significant 39% increase in the risk of death for up to 90 days after major orthopedic surgery.

Dr. Cohen says that heparin and other drugs to help prevent DVT are usually only given for up to ten days after surgery, even though the risk of DVT persists for much longer. "This results in an excess death rate of one in every 240 patients. The most common cause of death is pulmonary embolism," states Dr. Cohen. Pulmonary embolism is an obstruction of a blood vessel in the lungs, usually due to a blood clot, which blocks a coronary artery.

Dr. Cohen said current guidance to orthopedic patients is usually to "just be careful after surgery." He decided to speak out publicly out of frustration that findings published in journals have not changed medical practice.