Extended use of bemiparin as thromboprophylaxis during bariatric surgery: results of anti-factor Xa activity measurements

Abstract

BackgroundThe incidence of venous thromboembolism (VTE) in morbidly obese patients after obesity surgery is between .2% and 3.5%. Because there are a lack of prospective studies on the type of drug, the correct dosage, and the optimal duration, there are no specific recommendations found in the guidelines on thrombophylaxis. ObjectivesTo compare the incidence of VTE and hemorrhagic events in bariatric surgical patients receiving bemiparin thromboprophylaxis who have prophylactic and nonprophylactic Anti-factor Xa (AFXa) levels. SettingUniversity General Hospital of Ciudad Real, Spain, public practice. MethodsA cohort study of 122 morbidly obese patients who underwent bariatric surgery. The thromboprophylactic regimen consisted of bemiparin 5000 IU/24 hr for 30 days. AFXa levels were measured on the second and third day postoperation (prophylactic range: .3–.5 IU/mL). Body mass index, co-morbidities, prothrombotic risk factors, and thrombotic and hemorrhagic events were noted. ResultsThe mean body mass index was 48.4 kg/m2. In 50 samples, the level of AFXa was within the prophylactic range; in 71, they were in the subprophylactic range. No VTEs were observed. Major hemorrhagic events were observed in 2.4%. We did not find a significant association between AFXa and thromboembolic and hemorrhagic events. There is a significant negative correlation between the level of AFXa and body mass index. ConclusionA regimen of 5000 IU/24 hr of bemiparin for 30 days after obesity surgery appears to prevent VTE without increasing the risk of a major hemorrhage. The level of AFXa is not associated with postoperative thrombotic or hemorrhagic events occurring after bariatric surgery.