LOW-MOLECULAR-WEIGHT HEPARIN AND UNFRACTIONATED HEPARIN FOR PREVENTION OF THROMBOEMBOLISM IN GENERAL-SURGERY - A METAANALYSIS OF RANDOMIZEDCLINICAL-TRIALS

Low molecular weight heparin (LMWH), unfractionated heparin (UFH) and warfarin were compared with respect to efficacy and safety in the prev ention of thrombo-embolism in general surgery. Meta-analysis (MA) with a priori definition of the MA protocol was used to combine the result s from randomised trials with patients who underwent general surgery a nd deep-vein thrombosis (DVT) prophylaxis with LMWH, UFH or warfarin. Forty-four studies were identified for assessment and 33 were included , however, none for warfarin. For efficacy (DVT and pulmonary embolism ) and major bleeding, no significant difference between the LMWH- and UFH-treated groups was demonstrated. The relative risk of minor bleedi ngs for LMWH versus UFH was 0.75 (0.64-0.88; 95% confidence interval) and is significant (p<0.05). Within the limitations of the MA, LMWH an d UFH did not differ significantly in terms of prevention of thrombo-e mbolism, but LMWH had a significantly better safety profile. On this b asis, LMWH may be preferable to UFH in the prevention of thrombo-embol ism in general surgery.