Deep venous thrombosis (DVT), the formation of blood clots in the lower limbs, is the third-most common vascular disease in North America after heart attack and stroke, and is a frequent complication in hospitalized patients.
DVT is a potentially serious condition that can lead to rapid death from pulmonary embolism if untreated, and has become such a serious health concern that the U.S. Surgeon General and the Canadian Safer Healthcare Now! coalition both recently issued highly publicized calls to action to reduce the number of cases of DVT in high risk groups, in part by improving the adoption of preventative measures like the early administration of blood thinners.
However, researchers at McGill University and the affiliated Jewish General Hospital – along with colleagues from Université de Montréal, McMaster University and other institutions – warn that, beyond the well-known risks of pulmonary embolism, DVT patients also face postthrombotic syndrome (PTS), a poorly understood, long-term complication not addressed by traditional treatment approaches like blood thinners. Their conclusions, derived from a large, multicentre Canadian study, were published in the November issue of the Annals of Internal Medicine.
The study followed 387 patients at eight hospital centres in Quebec and Ontario for two years, the researchers said, the first multicentre study of PTS ever undertaken in North America.
"Incredibly, we found as many as 43 per cent of the patients developed postthrombotic syndrome, and one-third of those had moderate to severe cases," said McGill's Dr. Susan R. Kahn, lead author of the study. "The syndrome is characterized by persistent leg pain and swelling, and in severe cases, patients can develop painful leg ulcers which are very difficult to treat.