General Papers 17

Aims: Major general surgical operations, especially for malignancy, are associated with a high risk of venous thrombo-embolic (VTE) complications, of which about 40 per cent occur after discharge. In this systematic review we examine the value of extended thrombo-prophylaxis. Methods: Three randomized, controlled trials, which studied 1 week versus 4 weeks of thromboprophylaxis (TP) with low molecular weight heparin (LMWH), were included in the analysis. We used RevMan (Version 4.1.1, Oxford & England 2000) to perform the meta-analysis using fixed odds ratio (OR) to compare groups. All patients undergoing venography were considered and only objectively confirmed VTE events were included in the efficacy analysis. All patients randomized to prolonged prophylaxis and who received a dose of study drug were considered in the safety analysis. Results: A total of 683 patients were randomized to receive LMWH for 1 week (333 patients) or 4 weeks (350 patients). Total VTE events occurred in 16 (4.8 per cent) patients in the extended group and 40 (11.4 per cent) in the control group (OR = 0.39, 95 per cent CI 0.21–0.71; P = 0.002). The risk of bleeding was 3.5 per cent in both groups (OR 0.99, 95 per cent CI 0.47–2.06; P = 1). Conclusions: Extended TP results in significant reduction of the risk of developing VTE in patients undergoing major general surgical operations without any increase in the risk of bleeding.