Increased risk of postoperative complications with retromuscular mesh placement in emergency incisional hernia repair: A nationwide register-based cohort study.

INTRODUCTION Incisional hernia is common after abdominal surgery. Watchful waiting carries the risk of incarceration and a need for emergency intervention. The aim of this study was to examine the risk of postoperative complications after emergency versus elective incisional hernia repair. METHODS Patients above 18 years of age undergoing open incisional hernia repair in Denmark in 2017-2018 were identified in the Danish Ventral Hernia Database. Patients were grouped according to elective or emergency hernia repair. The primary outcome was postoperative complications requiring operative intervention within 90 days, and the secondary outcome was postoperative length of stay. RESULTS We included 1050 patients, of whom 882 were admitted for elective and 168 for emergency operation. Patients undergoing emergency repair were older (64.7 years vs 59.2 years, p < 0.001), more often smokers (25.8% vs 13.6%, p = 0.003), and more often had a Charlson comorbidity score ⩾2 (26.8% vs 19.2%, p = 0.005) compared to patients undergoing elective repair. In a multivariate regression analysis, emergency compared to elective operation (OR = 2.71, 95% CI = 1.4-5.25, p = 0.003) and retromuscular compared to onlay mesh placement (OR = 2.14, 95% CI = 1.08-4.24, p = 0.013) were factors significantly associated with increased risk of postoperative complications. In a subgroup analysis including only emergency repairs, risk of complications after retromuscular mesh placement was even higher (OR = 10.12, 95% CI = 1.81-56.68, p = 0.008). CONCLUSION Emergency incisional hernia repair was associated with increased risk of postoperative complications and this risk was accentuated with retromuscular mesh placement. The use of retromuscular mesh in the emergency setting should be avoided, and the abdominal wall could either be closed by sutures or additional onlay mesh.