Predicting incisional hernia after bariatric surgery: a risk stratification model based upon 2161 operations.

Background: Incisional hernia (IH) is a persistent cause of morbidity and diminished quality of life and a substantial source of healthcare resource utilization. The literature suggests prophylactic mesh augmentation reduces IH risk in bariatric surgery, but no predictive models are available. Objectives: Identify factors associated with HI after bariatric surgery to develop a clinically actionable preoperative risk stratification tool to optimize outcomes and mitigate healthcare costs after bariatric surgery. Setting: University hospital, United States. Methods: All patients undergoing open or laparoscopic bariatric surgery from January 2005 to June 2013 at one institution were identified. Co-morbidities and operative characteristics were assessed. The primary outcome was surgically treated IH after index procedures. Patients with prior hernia, <1-year follow-up, or body mass index <40 kg/m(2) were excluded. Cox hazard regression modeling with bootstrapped validation, risk factor stratification, and assessment of model performance were conducted. Results: A total of 2161 bariatric patients were included, 2.4% of whom developed IH (follow-up 28.3 +/- 25.4 mo). Predictors for IH included open surgical approach (hazard ratio [BR] = 10.3), malnutrition (HR = 3.10), prior abdominal surgery (HR = 2.89), and body mass index > 60 kg/m(2) (HR = 2.60). Based on these risk factors, patients were stratified into low-, moderate-, and high-risk categories for IH development. Of the high-risk patients, 15.2% developed IH compared with .6% of low-risk patients (C-statistic = .85). Treatment of IH and associated complications exceeded $3.5 million in healthcare costs. Conclusion: Bariatric surgery conferred an IH risk of 2.4%. IH was associated with additional readmissions and complications and substantially greater costs and resource utilization. This risk stratification tool identifies candidates for prophylactic mesh augmentation, which may optimize outcomes while mitigating costs. (C) 2016 American Society for Metabolic and Bariatric Surgery. All rights reserved.