Why does Parastomal Hernia Occur in Facilities with Permanent End Sigmoid Colostomy Based on the Extraperitoneal Route?

Abstract AIM: The incidence of parastomal hernia (PH) following the transperitoneal end sigmoid colostomy (TP) with prophylactic mesh placement has been reported unexpectedly high. We reviewed the incidence of PH after laparoscopic abdominoperineal excision (lap APE) using extraperitoneal end sigmoid colostomy (EP) in principle since 2013 to examine the appropriateness of prophylactic mesh placement for PH prevention in the laparoscopic setting. MATERIALS AND METHODS: From September 2013 to August 2021, 28 consecutive patients underwent lap APE for local curative resection of rectal adenocarcinoma with a postoperative follow-up period of at least 20 months at the Department of Gastrointestinal Surgery, Kansai Medical University Hospital. We diagnosed a PH (+) based on either the findings of a follow-up CT examination or those of a certified wound, ostomy, and continence nurse. We examined the causes of PH based on the clinical and surgical findings. RESULTS: We have experienced PH in 6 out of 28 patients (PH (+)). Of these, 5 were cases where EP was technically abandoned in favor of TP. The Cox proportional hazard model revealed that the risk factors of the PH were significant in the TP (relative risk = 46.8; 95% confidence interval = 2.3–940.4). The Kaplan–Meier curve showed that the 3-year PH occurrence rate was significantly lower in EP (5.1%) than in TP (71.4%; P < 0.001). CONCLUSION: The EP is a highly effective method for preventing PH, and the intraperitoneal onlay mesh methods, in which TP is used as a pseudo-EP in cases where TP is necessary, warrants further investigation.