Background: Deep Venous Thrombosis (DVT) is a major risk of morbidity and mortality in morbid obese patients underwent bariatric surgery. There are some controversies in different kind of prophylactic strategies for DVT in laparoscopic bariatric surgeries. Unfractionated heparin (UFH) is an available and reversible anticoagulant used for DVT prophylaxis.

Objectives: This study aimed to compare clinical results of two different dosage regimes of unfractionated heparin for short term prophylaxis of DVT after bariatric surgery.

Patients and Methods : 139 patients with morbid obesity who underwent laparoscopic bariatric surgery (laparoscopic Roux-en-Y gastric bypass, sleeve gastrectomy, and laparoscopic gastric banding) were evaluated in two groups: group A received 5000 IU unfractionated heparin q12h and group B received the same dose but q8h ( preliminary dose received before induction of anesthesia followed by 2 or 3 times daily). All patients were evaluated by physical examination and Doppler ultra sound for DVT before and 10 days after surgery.

Results: There was no statistically significant difference between two groups in venous thrombosis. No thrombotic events were observed before and after operations. There were no heparin induced thrombocytopenia and no meaningful difference between two groups in postoperative bleeding.

Conclusions: This study showed that in combination with non-pharmacologic methods for prevention of thromboembolic events, both regimes of UFH prophylaxis had similar clinical effects.