Tissue Reaction to Monofilament Grafts of Different Weights Used for Abdominal Wall Reinforcement

Background/Objectives: Hernia and pelvic organ prolapse often involve defects necessitating reinforcement with synthetic materials. Polypropylene meshes of varying weights are commonly used in abdominal wall repair; however, their impact on tissue response, potentially linked to adverse events during wound healing, remains incompletely understood. This study aimed to evaluate and compare the tissue response to lightweight polypropylene (LWPP) and heavyweight polypropylene (HWPP) grafts used for abdominal wall defect closure in Wistar rats. Methods: Abdominal wall defects were surgically created in male Wistar rats and repaired using either LWPP (43 g/m²) or HWPP (76 g/m²) mesh. Three weeks post-implantation, tissue response and wound closure were evaluated across different phases by assessing expression of CD68, CD56, GATA-3, CD138, vimentin, α-smooth muscle actin, and collagen deposition. Results: HWPP promoted a more pronounced foreign body response, as evidenced by increased CD68, CD56, and CD138 expression, while LWPP improved tissue compliance, enhanced fibroblast migration, and increased vimentin-associated cellular activity. Conclusions: Three weeks post-implantation, HWPP was found to induce a stronger inflammatory response, whereas LWPP implantation was associated with increased vimentin expression, indicating differences in the balance between inflammation and extracellular matrix remodelling during early wound healing.