Comparison of intra-abdominal adhesions formation following implantation of synthetic, biosynthetic, and biologic meshes in a rat model.

Abstract

Background: Intra-abdominal adhesions remain a significant challenge in incisional hernia repair, often resulting in complications such as bowel obstruction and chronic pain. Although various prosthetic meshes have been developed, their comparative adhesion profiles have not been fully elucidated. This experimental study aimed to compare the severity of intra-abdominal adhesions and the associated histopathological responses induced by synthetic, biosynthetic, biological, and chemically treated meshes in a standardized rat model.

Methods: Fifty Wistar albino rats were randomly assigned to five groups (n=10 each): control, polypropylene mesh (Prolene®), polypropylene mesh impregnated with tissue adhesive (Tisseel®), dual mesh (Gore® DualMesh®), and biological mesh (Permacol®). A standardized 2×2 cm full-thickness abdominal wall defect was created in each animal, followed by intraperitoneal mesh implantation. On post-operative day 30, macroscopic adhesions were assessed using the Modified Diamond Scale. Histopathological evaluation included grading of fibrosis, inflammation, vascular proliferation, and giant cell reaction. Statistical analysis was performed using the Kruskal-Wallis test and post hoc multiple comparison analyses.

Results: The Prolene mesh group demonstrated the highest adhesion severity (mean Modified Diamond score: 2.80±1.23), which was significantly greater than that observed in the biological mesh (p=0.010), dual mesh (p=0.002), and tissue adhesive-impregnated Prolene groups (p=0.033). Fibrosis and inflammation were also most pronounced in the Prolene and dual mesh groups, whereas the biological mesh group exhibited milder responses (fibrosis p=0.028; inflammation p=0.033 compared to Prolene). Vascular proliferation and giant cell counts were significantly lower in the biological mesh group (p=0.004 and p<0.001, respectively).

Conclusion: Biological and dual meshes, as well as tissue adhesivetreated meshes, were associated with significantly reduced adhesion formation and milder histopathological responses compared to untreated polypropylene mesh. Although no material completely prevented adhesion formation, low-porosity meshes and anti-adhesive strategies appear promising for reducing adhesion-related morbidity in intraperitoneal hernia repair. Further studies are warranted to confirm these findings and optimize mesh selection.