PROPHYLAXIS OF VENOUS THROMBOEMBOLISM WITH LOW MOLECULAR WEIGHT HEPARIN IN BARIATRIC SURGERY: A PROSPECTIVE, RANDOMISED PILOT STUDY EVALUATING TWO DOSES OF PARNAPARIN (BAFLUX STUDY)

Background: The optimal dose of low molecular weight heparin (LMWH) to prevent venous thromboembolism (VTE) after bariatric surgery remains controversial. The aim of this multicentre, open-label, pilot study was to evaluate the efficacy and safety of two different doses of the LMWH parnaparin administered to patients undergoing bariatric surgery. Methods: Patients were randomised to receive 4,250 IU/day (group A) or 6,400 IU/day (group B) of parnaparin s.c. for 7-11 days. Bilateral colour Doppler ultrasound of the lower limb was performed before surgery and at the end of the treatment period. The primary efficacy outcome was a composite of asymptomatic and symptomatic deep vein thrombosis, symptomatic pulmonary embolism and death from any cause during treatment. The primary safety endpoint was major and clinically relevant non-major bleeding. Results: A total of 258 patients underwent randomization; 8 subjects were excluded following the safety analysis. One hundred thirty-one patients [106 females; mean age, 40.3 years (standard deviation (SD) ±9.6); mean body mass index (BMI), 44.6 kg/m2 (SD ±5.4)] were assigned to group A and 119 patients [93 females; mean age, 41.5 years (SD ±9.9); mean BMI, 44.2 kg/m2 (SD ±5.4)] were assigned to group B. The rate of the primary efficacy outcome was 1.5 % (two cases; 95 % confidence interval (CI), 0.2-6.0 %) in group A as compared with 0.8 % (one case; 95 % CI, 0.4-5.3 %) in group B (p = ns). The composite incidence of major bleeding and clinically relevant non-major bleeding was 6.1 % (eight cases; 95 % CI, 2.9-12.1 %) in group A and 5.0 % (six cases; 95 % CI, 2.1-11.1 %) in group B (p = ns). Conclusions: A parnaparin dose of 4,250 IU/day seems suitable for VTE prevention in patients undergoing bariatric surgery. © 2013 The Author(s).