A controlled trial of two low-dose heparin regimens for the prevention of postoperative deep vein thrombosis

Abstract

Venous thromboembolism is a serious complication following gynecologic surgery and is particularly common in patients with malignancy. A previous study of subcutaneous low-dose heparin given as one dose preoperatively and every 12 hours postoperatively failed to show a benefit in gynecologic oncology patients. In the present study, two more intense regimens of low-dose heparin were evaluated. Three hundred four patients were assigned randomly to receive no prophylaxis (controls), subcutaneous heparin 5000 units 2 hours before surgery and every 8 hours postoperatively (low-dose heparin) (regimen I), or 5000 units heparin subcutaneously every 8 hours preoperatively (between two and nine doses) and every 8 hours postoperatively (regimen II). All patients had thromboembolism surveillance with the fibrinogen uptake test and clinical evaluation. Eighty-four percent had a malignancy. Thromboemboli were diagnosed in 19 of 103 control patients, ten of 104 regimen I patients, and six of 97 regimen II patients, a statistically significant difference (P less than .008). When compared with the control group, the study groups had no evidence of increased bleeding complications or alteration of laboratory coagulation indicators.