Incidence of lower limbs deep vein thrombosis after open and laparoscopic gastric bypass: a prospective study.

Background: Lower limbs deep vein thrombosis (DVT) and pulmonary embolism (PE) are major causes of morbidity and mortality and are even higher in bariatric patients. The longer operative time and higher immobility in these patients increase the DVT risk. Although deaths after bariatric surgery have been reported, there is no consensus regarding the prophylaxis of DVT. This study's objective is to determine the incidence of lower limbs DVT in patients submitted to Roux-en-Y-gastric bypass (RYGBP) under prophylaxis by enoxaparin.

Methods: Patients with body mass index (BMI) equal to or higher than 35 kg/m(2) who submitted to RYGBP by laparotomy or laparoscopy using 40 mg/day of enoxaparin for 15 days were recruited between October 2004 and August 2005. Individuals with previous DVT and heparin allergy were excluded. Patients were tested for DVT using color Doppler ultrasound performed before surgery and on the second and fifth weeks after surgery.

Results: The study population included 136 patients, with 126 concluding the protocol. There were 79% (100/126) of female patients aged 19 to 65 years old, with mean of 40 years SD = 10 and BMI between 35 and 61 kg/m(2), mean of 43 kg/m(2) (SD = 5). All patients who submitted to RYGBP were divided as 55% (69/126) by laparoscopy and 45% (57/126) by laparotomy. The incidence rate of lower limbs DVT was 0.79% (1/126).

Conclusion: The low incidence rate of DVT found in our study suggests that obesity might not be a major risk factor for venous thromboembolism in patients submitted to RYGBP.