Prophylaxis of Venous Thromboembolism with Low Molecular Weight Heparin in Bariatric Surgery: a Prospective, Randomised Pilot Study Evaluating Two Doses of Parnaparin (BAFLUX Study)

Abstract

BackgroundThe 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.MethodsPatients 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.ResultsA 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).ConclusionsA parnaparin dose of 4,250 IU/day seems suitable for VTE prevention in patients undergoing bariatric surgery.

Perioperative rates of deep vein thrombosis and pulmonary embolism in normal weight vs obese and morbidly obese surgical patients in the era post venous thromboembolism prophylaxis guidelines

“…Several studies have evaluated the risk of VTE in the bariatric surgery patient population. [10][11][12] However, there is scarcity of data describing its efficacy in obese and morbidly obese patients outside of bariatric surgery. Based on this growing awareness of VTE in obese patients, as well as the push toward strict implementation of VTE protocols, we hypothesized that obesity would not confer increased risk of VTE in the patient undergoing nonbariatric abdominal surgery.…”

Weight‐adjusted tinzaparin for the prevention of venous thromboembolism after bariatric surgery

“…These results are consistent with other studies suggesting that weight‐adjusted LMWH‐based VTE prophylaxis may be more efficacious than a fixed, lower‐dose LMWH regimen after bariatric surgery. The optimal dose of LMWH after bariatric surgery is unclear, with smaller randomized trials suggesting that adjusting for weight does not significantly reduce the risk of postoperative VTE . However, a meta‐analysis totaling 1858 patients found that patients receiving weight‐adjusted prophylaxis with UFH or LMWH had a lower rate of in‐hospital VTE compared with fixed lower‐dose regimens (0.5% vs. 2.0%), with similar rates of major bleeding (1.6% vs. 2.3%) .…”

“…The optimal pharmacologic VTE prophylaxis strategy after bariatric surgery is uncertain and needs to address the dose and duration of anticoagulants. In general, studies assessing prophylaxis with low‐molecular‐weight heparin (LMWH) after bariatric surgery demonstrate variable VTE rates between 0% and 5.4%; such variability in VTE rates probably reflects differences in LMWH dose regimens administered (fixed vs. weight‐adjusted), the duration of prophylaxis (inpatient vs. extended outpatient), and outcomes assessed (asymptomatic vs. symptomatic VTE) . Similarly, rates of major bleeding with LMWH prophylaxis also vary widely, between 0% and 6.7% .…”

Pulmonary embolism and gastrointestinal leak following bariatric surgery: when do major complications occur?

“…A survey of bariatric surgeons suggested that 48.3% continue anticoagulation after discharge, but the response rate to the survey was not provided [28]. Furthermore, 2 recent prospective randomized trials of anticoagulation modalities for bariatric patients limited the duration of prophylaxis to in-hospital or o10 days, respectively [29,30]. This is in contrast to a systematic review that recommended 1-month prophylaxis in patients undergoing major open or laparoscopic abdominal or pelvic surgery [15].…”