The use of enoxaparin as venous thromboembolism prophylaxis in bariatric surgery: A retrospective cohort study.

Introduction: Venous thromboembolism (VTE) is one of the major causes of morbidity and mortality in bariatric patients. The use of low-molecular-weight heparin (LMWH), as enoxaparin, is considered one of the mainstays thromboprophylaxis regimens in postoperative bariatric patients. Despite the universal agreement on the importance of thromboprophylaxis in these patients, there are inadequate strong recommendations for its dosing and duration. The aim of our study is to explore the current practice on using enoxaparin in bariatric patients, as well as to assess both the efficacy and safety of varying dosing regimens.
Material and Methods: This is a retrospective cohort study of morbidly obese patients who underwent bariatric procedure at a tertiary care hospital between 2016 and 2019. All adult patients who met the eligibility criteria for bariatric surgery and received enoxaparin with a minimum follow-up period of one month were included in our study. Participants with a history of coagulopathy, renal or hepatic insufficiency were excluded from the study. Data collected include patient demographics, VTE risk factors, and co-morbidities. The outcome of treatment failure was defined as the composite of either VTE or major bleeding.
Results: A total of 1,169 patients who underwent bariatric surgery were included in the study. The mean age was 35.54 years, with mean body mass index (BMI) of 45.78 kg/m ² . The mean duration of enoxaparin use was 9 days, and the majority of patients (78%) received a prophylaxis dose of 40 mg subcutaneously (SC) once daily. The overall rate of VTE at 90 days was 1.4% while only 0.1% of patients developed major bleeding. There was no statistically significant difference in patients' age, gender, BMI, or various enoxaparin dosing regimens between patients who developed VTE or bleeding versus patients who did not develop. Patient's weight was the only statistically significant risk factor that directly correlated to higher risk of complications (P = 0.006). In the multivariable logistic regression model, higher BMI was significantly associated with treatment failure, either VTE or major bleeding [OR 1.05 (95% CI 1.0-1.09); P = 0.038].
Conclusions: The rate of VTE or major bleeding did not differ in patients who received various enoxaparin regimens. Patients undergoing bariatric surgery may benefit from enoxaparin thromboprophylaxis dose of 40 mg SC daily for a total duration of 14 days, with higher doses may be needed for extremely obese patients. We recommend standardizing the current practice of VTE prophylaxis post bariatric surgery and unifying the optimal dose and duration.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(© 2022 The Authors.)