Primary and incisional hernias should be considered separately in clinical decisions and research: A nationwide register-based cohort study.

Abstract

<h4>Background</h4>Ventral hernias of umbilical, epigastric, and incisional types pose varied surgical challenges. Recent debates and research suggest that treatment strategies and outcomes may vary significantly based on hernia type and width. This study investigated whether differences in the risk of surgical outcomes among primary and incisional hernias are solely due to the hernia type. The primary outcome was reoperation for recurrence, and the secondary outcome was 90-day postoperative readmission.<h4>Methods</h4>This study was based on prospectively collected data from the Danish Ventral Hernia Database linked with the Danish Civil Registration system and the National Patient Register. Data spanned from 2007 to 2022 and included patients with umbilical, epigastric, or incisional hernias. The 3 hernia types were analyzed for the risk of reoperation for recurrence, adjusted for sex, age, emergency repair, width, use of mesh, and Charlson comorbidity index.<h4>Results</h4>We included 57,312 hernias: 34,147 umbilical, 9,433 epigastric, and 13,722 incisional hernias. Compared with patients with umbilical hernias, patients with epigastric hernias had a lower risk of reoperation (hazard ratio: 0.88, 95% confidence interval: 0.79-0.99) and those with incisional hernias had an increased risk (hazard ratio: 2.93, 95% confidence interval: 2.57-3.33). Postoperative 90-day readmission rates were also higher for patients with incisional hernias than for patients with umbilical and epigastric hernias.<h4>Conclusion</h4>Incisional hernias exhibited a higher risk of reoperation for recurrence and 90-day postoperative readmission, underscoring their unique nature in terms of both origin and clinical behavior. The findings suggest that primary and incisional hernias should be separate entities in medical practice and research.