[Treatment of established venous thrombosis with low molecular weight heparins. A critical review]

Low-molecular weight heparin (LMWH) fractions have progressively replaced standard heparin for the prevention of postoperative deep venous thrombosis (DVT). The improved bioavailability and increased half-life of these fragments allowed indeed to prevent DVT while using one single daily subcutaneous injection instead of two or three with standard heparin, a clear-cut advantage both for the patient and the nurse. In the treatment of established DVT, the presently available data suggest that these fractions, administered in 2 daily subcutaneous injections, are equivalent to standard heparin with regard to the effects on the phlebogram and to the risk of major bleeding. However, there are no definitive data on the prevention of pulmonary embolism which is the primary aim of anticoagulant treatment in established DVT, there is no clear-cut advantage for the LMWH fractions in this indication, except if laboratory control can be omitted, which is still matter of debate.