Effect of BMI on Outcomes in Proctectomy

BACKGROUND: The unique surgical challenges of proctectomy may be amplified in obese patients. We examined surgical outcomes of a large, diverse sample of obese patients undergoing proctectomy. OBJECTIVE: The purpose of this work was to determine whether increased BMI is associated with increased complications in proctectomy. DESIGN: This was a retrospective review. SETTINGS: The study uses the American College of Surgeons National Surgical Quality Improvement Program database (2010 and 2011). PATIENTS: Patients included were those undergoing nonemergent proctectomy, excluding rectal prolapse cases. Patients were grouped by BMI using the World Health Organization classifications of underweight (BMI <18.5); normal (18.5-24.9); overweight (25.0-29.9); and class I (30.0-34.9), class II (35.0-39.9), and class II (>= 40.0) obesity. MAIN OUTCOME MEASURES: We analyzed the effect of preoperative and intraoperative factors on 30-day outcomes. Continuous variables were compared with Wilcoxon rank-sum tests and proportions with the Fisher exact chi(2) tests. Logistic regression controlled for the effects of multiple risk factors. RESULTS: Among 5570 patients, class I, II, and II obesity were significantly associated with higher rates of overall complications (44.0%, 50.8%, and 46.6% vs 38.1% for normal-weight patients; p < 0.05). Superficial wound infection was significantly higher in classes I, II, and II 11.6%, 17.8%, and 13.0% vs 8.0% for normal-weight patients; p < 0.05). Operative times for patients in all obesity classes were significantly longer than for normal-weight patients. On multivariate analysis, an obese BMI independently predicted complications; ORs (95% CIs) were 1.36 (1.14-1.62) for class I obesity, 1.99 (1.54-2.54) for class II, and 1.42 (1.02-1.96) for class II. LIMITATIONS: This study was a retrospective design with limited follow-up. CONCLUSIONS: Class I, II, and II obese patients were at significantly increased risk for morbidity compared with normal BMI patients. Class II obese patients had the highest rate of complications, a finding that deserves further investigation.