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

Surg Obes Relat Dis. 2018 Mar;14(3):354-360. doi: 10.1016/j.soard.2017.12.004. Epub 2017 Dec 14.


Background: The 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.

Objectives: To 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.

Setting: University General Hospital of Ciudad Real, Spain, public practice.

Methods: A 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.

Results: The 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.

Conclusion: A 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.

Keywords: Bariatric surgery; Bemiparin; Morbid obesity; Venous thromboembolism.

Publication types

  • Clinical Trial
  • Comparative Study

MeSH terms

  • Adult
  • Anticoagulants / administration & dosage*
  • Bariatric Surgery / adverse effects*
  • Bariatric Surgery / methods
  • Body Mass Index
  • Drug Administration Schedule
  • Factor Xa / metabolism*
  • Heparin, Low-Molecular-Weight / administration & dosage*
  • Humans
  • Middle Aged
  • Obesity, Morbid / surgery*
  • Operative Time
  • Postoperative Complications / prevention & control
  • Postoperative Hemorrhage / etiology
  • Prospective Studies
  • Risk Factors
  • Treatment Outcome
  • Venous Thromboembolism / prevention & control*
  • Young Adult


  • Anticoagulants
  • Heparin, Low-Molecular-Weight
  • Factor Xa
  • bemiparin