Fatal Pulmonary Embolism After Bariatric Operations for Morbid Obesity: a 24-year Retrospective Analysis

Background: Pulmonary embolism (PE) is a leading cause of death following gastric bypass operations for morbid obesity. Although its incidence appears to be stable, the number of bariatric operations performed annually is increasing considerably; hence, the isolated fatal PE is no longer a rare occurrence. The records of patients undergoing bariatric surgical operations since 1979 were reviewed to determine specific factors that increased the risk of developing a fatal PE. Both recommended and optional indications for prophylactic inferior vena cava (IVC) filter placement in patients considered at high risk were also examined.

Materials And Methods: Between September, 1979 and March, 2003, 5,554 operations were performed for clinically severe obesity. These operations included jejuno-ileal bypass, horizontal gastroplasty, Roux-en-Y gastric bypass with a 30-cc pouch, modified biliopancreatic diversion, the Sapala-Wood Micropouch gastric bypass (Micropouch(SM)), Lap-Band, and revisions. 12 fatal pulmonary emboli (0.21 %) were identified. All but 1 embolus occurred within 30 days following surgery.

Results: In 11 of 12 patients, at least 1 co-morbidity known to increase the risk of postoperative venous thromboembolism (VTE) was identified. 4 co-morbidites were common to 4 patients (33%): venous stasis disease (VSD), BMI >/= 60, truncal obesity, and obesity hypoventilation syndrome/sleep apnea syndrome (OHS/SAS). 6 of 12 patients (50%) had a BMI >/= 60. Another 6 had chronic leg swelling with stasis dermatitis. 2 patients experienced a previous PE, and 1 patient reported a history of deep vein thrombosis (DVT).

Conclusion: 4 patients (33%) demonstrated a combination of risk factors (VSD, BMI >/= 60, truncal obesity, OHS/SAS) recognized as significant for the development of postoperative VTE. In such patients, prophylactic IVC filter placement is highly recommended. Filter placement for other factors, such as age, body build, hypercoagulable state, etc., should be considered on an individual basis.