Incidence of ventral hernia surgery after laparoscopic bariatric surgery in Sweden: a register study 2009-2019

Abstract Introduction The incidence of trocar site hernia (TSH) after bariatric surgery is unclear. This study aims to describe the cumulative incidence of ventral hernia surgery after laparoscopic bariatric surgery in total and by method (LRYGB; Roux-en-Y Gastric Bypass and LSG; Sleeve Gastrectomy). Method This was a register based observational study on 63 899 patients subjected to laparoscopic bariatric surgery (LRYGB or LSG) in Sweden 2009-2019. The Scandinavian Obesity Surgery Registry (SOReg) was linked to the Swedish National Patient Register (NPR) to obtain instances of ventral hernia surgery. Nearby codes were used as proxies for TSH surgery, as this procedure lacks code. Result In 63 899 patients, mean follow-up was 66 months (SD 36), LRYGB (n=51 821) 74 months (SD 34) and LSG (n=12 078) 34 months (SD 22). Mean time between bariatric- and ventral hernia surgery was 35 months (SD 28, range 0-129). The five-year cumulative incidence of surgery for ventral hernia was 2.9 % (CI 2.8-3.0). The probability of having hernia surgery was significantly higher for LRYGB compared to LSG (Breslow test, p<0.001), also after assessment for a follow-up time varying effect (p<0.001). Discussion The incidence of surgery for ventral hernia after laparoscopic bariatric surgery is not negligible in this material on over a decade of bariatric procedures, and hernia repairs occurred throughout the study period. Ventral hernia surgery was more common after gastric bypass than after sleeve gastrectomy.