Systematic review and meta-analysis of prophylactic mesh during primary stoma formation to prevent parastomal hernia

Background: Implantation of mesh at the time of stoma formation may reduce the rate of parastomal hernia. Until recently the evidence has been limited to only a few small randomised controlled trials. Aim: We present an updated systematic review and meta-analysis to assess the effect of mesh prophylaxis on rates of parastomal hernia. We examine ongoing and unpublished trials via online registries and propose recommendations for future research. Data Sources: MEDLINE, EMBASE and the Cochrane Library were searched up to March 2016 for published randomised controlled trials. Sixteen international trial registries were inspected for ongoing and unpublished trials. Study Selection Randomised controlled trials comparing mesh versus no mesh on the incidence of parastomal hernia after colostomy or ileostomy formation. Main Outcome Measures: The primary outcome measure was rate of parastomal hernia at least 12 months after stoma formation. Secondary outcomes included rates of stoma-related complications. Results: Of 3005 studies identified, 7 RCTs (432 patients) were eligible for inclusion in the final analysis. All were at high risk of bias. Mesh reduced the incidence of clinically detected parastomal hernia (10.8% versus 32.4%; P=0.001) (RR 0.34, CI 0.18 to 0.65, I2=39%) and the rate of radiological detected parastomal hernia (34.6% versus 55.3%; P=0.01) (RR 0.61, CI 0.42 to 0.89, I2=44%). No increase in the incidence of stoma-related complications was observed with the use of prophylactic mesh. Results from ongoing and unpublished RCTs are expected, but few will report on alternative mesh types or surgical techniques. Limitations: Heterogeneity of interventions, small patient populations and a high risk of bias seen in all studies implicate cautious interpretation of the results. Conclusion: Mesh prophylaxis at the time of stoma formation appears safe and effective in preventing parastomal hernia, however limitations of the primary evidence justify larger, more rigorous RCTs.