A risk model and cost analysis of incisional hernia after elective abdominal surgery based on 12,373 cases. the case for targeted prophylactic intervention

Objectives: Incisional hernia (IH) remains a common, highly morbid, and costly complication. Modest progress has been realized in surgical technique and mesh technology; however, few advances have been achieved toward understanding risk and prevention. In light of the increasing emphasis on prevention in today's health care environment and the billions in costs for surgically treated IH, greater focus on predictive risk models is needed. Methods: All patients undergoing gastrointestinal or gynecologic procedures from January 1, 2005 to June 1, 2013, within the University of Pennsylvania Health System were identified. Comorbidities and operative characteristics were assessed. The primary outcome was surgically treated IH after index procedures. Patients with prior hernia, less than 1-year follow-up, or emergency surgical procedures were excluded. Cox hazard regression modeling with bootstrapped validation, risk factor stratification, and assessment of model performance were conducted. Results: A total of 12,373 patients with a 3.5% incidence of surgically treated IH (follow-up 32.2± 26.6 months) were identified. The cost of surgical treatment of IH and management of associated complications exceeded $17.5 million. Notable independent risk factors for IH were ostomy reversal (HR=2.76), recent chemotherapy (HR=2.04), bariatric surgery (HR=1.78), smoking history (HR=1.74), liver disease (HR=1.60), and obesity (HR=1.96). High-risk patients (20.6%) developed IH compared with 0.5% of low-risk patients (C-statistic=0.78). Conclusions: This study demonstrates an internally validated preoperative risk model of surgically treated IH after 12,000 elective, intra-abdominal procedures to provide more individualized risk counseling and to better inform evidence-based algorithms for the role of prophylactic mesh.