Incidence and risk factors of parastomal hernia after radical cystectomy and ileal conduit diversion: a systematic review and meta-analysis

Background: Our aim is to report the incidence and risk factors of parastomal hernia (PH) after radical cystectomy (RC) and ileal conduit (IC) diversion with a cumulative analysis. Methods: Various databases, including PubMed, the Cochrane Library, Embase and Web of Science, were retrieved electronically and manually to identify eligible studies from inception to August 20, 2020. Two reviewers independently searched the above databases and selected the studies using prespecified standardized criteria. The Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias in the included studies, and the data was completed by STATA version 14.2. Results: Fifteen studies were included in the final analysis. A pooled analysis of eight studies representing 1,878 patients reported the incidence of overall radiographic PH was 23% (95% CI: 17-29%). The 1-year PH incidence rate and 2-year incidence rate of RC and IC were 14% (95% CI: 6-22%) and 26% (95% CI: 14-38%), respectively. A pooled analysis of nine studies reported the incidence of clinically evident PH was 15% (95% CI: 10-19%). PH-related symptoms were reported in six studies, and the pooled result was 29% (95% CI: 24-33%), and a pooled analysis of ten studies showed that 20% (95% CI: 11-28%) of patients required surgical repair. However, it's noteworthy that among symptomatic PH patients undergoing surgical repair, the pooled analysis of five studies showed that up to 26% (95% CI: 16-36%) of patients suffered PH recurrence. The most frequent risk factor was body mass index (BMI). Patients with BMI = 22.9 kg/m(2) experienced 2.92-fold higher risk of PH than their counterparts [hazard ratio (HR): 2.92; 95% CI: 1.65-5.19]. Conclusions: Our findings indicated that the PH incidence rate after RC and IC was significantly higher in radiographic evaluation than that of clinical examination, and the recurrence of repairment is considerable for patients requiring reconstruction.