A comparative trial of a low molecular weight heparin (enoxaparin) versus standard heparin for the prophylaxis of postoperative deep vein thrombosis in general surgery

BACKGROUND: Various studies have been performed in general surgery patients comparing low molecular weight heparin (LMWH) with standard heparin (SH) for the prevention of postoperative deep vein thrombosis (DVT), revealing contradicting results. Therefore, we have compared the efficacy and safety of a LMWH for the prevention of DVT after major general surgery.

PATIENTS AND METHODS: Patients received either 20 mg LMWH (enoxaparin) once daily, or 5,000 IU SH TID, starting preoperatively in a prospective, randomized, double-blind international multicenter trial. DVT was diagnosed using fibrinogen I 125 leg scanning. Major and minor bleeding were assessed clinically.

RESULTS: A total of 718 patients were randomized to LMWH, and 709 patients to SH. DVT was detected in 58 LMWH-treated patients (8.1%, 95% confidence interval [CI] 6.2% to 10.3%) and in 45 patients allocated to SH (6.3%, 95% CI 4.7% to 8.4%, P > 0.05). Major bleeding complications occurred in 11 LMWH-treated patients (1.5%, 95% CI 0.8% to 2.7%) and in 18 patients to whom standard heparin was administered (2.5%, 95% CI 1.5% to 3.9%, P > 0.05). Four LMWH-treated patients (0.6%) required reoperation for bleeding as compared to 13 patients in the SH group (1.8%, P = 0.03).

CONCLUSION: This LMWH appeared as effective and safe as SH. In view of its more convenient way of administration, this LMWH might be preferred for thromboprophylaxis.