Comparison of coated meshes for intraperitoneal placement in animal studies: a systematic review and meta-analysis

Purpose Laparoscopic intraperitoneal onlay mesh in hernia repair can result in adhesions leading to intestinal obstruction and fistulation. The aim of this systematic review is to compare the effects of mesh coatings reducing the tissue-to-mesh adhesion in animal studies. Methods Pubmed and Embase were systematically searched. Animal experiments comparing intraperitoneally placed meshes with coatings were eligible for inclusion. Only studies with comparable follow-up, measurements, and species were included for data pooling and subsequent meta-analysis. Results A total of 131 articles met inclusion criteria, with four studies integrated into one comparison and five studies integrated into another comparison. Compared to uncoated polypropylene (PP) mesh, PP mesh coated with hyaluronic acid/carboxymethyl cellulose (HA/CMC) showed significantly reduced adhesion formation at follow-up of 4 weeks measured with adhesion score of extent (random effects model, mean difference,- 0.96, 95% CI - 1.32 to - 0.61, P <0.001, I-2 = 23%; fixed effects model, mean difference,- 0.94, 95% CI - 1.25 to - 0.63, P <0.001, I-2 = 23%). Compared to PP mesh, polyester mesh coated with collagen (PC mesh) showed no significant difference at follow-up of 4 weeks regarding percentage of adhesion-area on a mesh, using random effects model (mean difference - 11.69, 95% CI - 44.14 to 20.76, P = 0.48, I-2 = 92%). However, this result differed using fixed effects model (mean difference - 25.55, 95% CI - 33.70 to - 7.40, P <0.001, I-2 = 92%). Conclusion HA/CMC coating reduces adhesion formation to PP mesh effectively at a follow-up of 4 weeks, while the anti-adhesive properties of PC mesh are inclusive comparing all study data.