[Prevention of thrombo-embolic venous disease]

Large epidemiological studies have shown that nearly all risk factors for deep vein thromboses have a different impact on the manifestation of the disease, which aids in their differentiation into high, moderate and low risk. North American authors have introduced a fourth class of very high risk. The prophylactic measures available are numerous. They can be used in isolation or association depending on the significance of the risk. In France, prophylaxis by LMWH (low molecular weight heparin) is by far the most frequently used method. Recently, apart from compression stockings and intermittent mechanical compression, the use of footpumps, and a technique of electrical calf stimulation have been proposed. Each thrombosis center or service should put in place a well defined strategy for prescribing thromboprophylaxis, adapted to the level of the thromboembolic risk for each group of patients. A dose of LMWH higher than that used for a moderate risk is indicated for most LMWH, in the case of a high or very high risk. A few problems still exist: the pre or postoperative timing of the first injection, the duration of the prophylaxis particularly during the post-discharge period, and the evaluation of the risk in certain situations such as laparoscopic surgery or limb immobilization, for which the studies are too few to formulate recommendations from the level of evidence available. The socioeconomic realities of using LMWH should not be ignored.