[Histological changes in intraperitoneal onlay mesh (IPOM) with synthetic and biological meshes. Results of the...

The objective of the study was to analyze histological changes in the site of the meshes FTOREX, FTOREX coated with carboxymethylcellulose, Ventralight ST, Symbotex, REPEREN-16-2 and decellularized porcine peritoneum on the parietal peritoneum of the pig.

At laparoscopy, 6 different meshes were placed intraperitoneally in each of the 3 pigs. After 90 days, the animals were taken out of the experiment. After staining with hematoxylin and eosin, quantitative morphometry and counting the number of vessels and cells in the interstitium in the areas of the mesh and peritoneum were performed. An immunohistochemical study with an antibody to pancytokeratins assessed the state of the initial peritoneum and neoperitoneum.

According to morphological characteristics, the meshes were divided into 3 groups: 1) with fluoropolymer coating FTOREX, 2) Ventralight ST and Symbotex, 3) REPEREN and decellularized peritoneum. In group 1, the surface area of the mesh threads was optimal in terms of the arrangement and arrangement of the threads relative to each other. This contributed to the formation of a relatively dense fibrous framework and a place to preserve the underlying peritoneum involved in the formation of the neoperitoneum. Despite the smallest surface area of the threads, in group 3, the greatest fibroblastic reaction was noted. Inflammatory changes were the least pronounced in group 1. They were the greatest in group 3, where there was a pronounced leukocyte reaction, combined with the processes of metaplasia, the development of fibrinoid necrosis, and the progression of the secondary inflammatory process. In group 1, the optimal ratio of newly formed vessels was noted, in group 2 - veins prevailed over arteries, in group 3 - the number of vessels was minimal. Immunohistochemical study showed that in group 1, mesothelial cells covered almost the entire surface of the implant, and there were also areas of preserved basic peritoneum. In group 2, mesothelium also covered most of the surface of the meshes, but the underlying peritoneum was absent. In group 3, on the contrary, a significant number of extended areas not covered with mesothelium were revealed.

The conducted morphological and morphometric study showed that the most balanced ratio of the components of the newly formed fibrous tissue and blood vessels is observed when using implants with a fluoropolymer coating FTOREX. At the same time, the remaining basic peritoneum actively participated in the formation of the neoperitoneum. The Ventralight ST and Symbotex meshes also contributed to the formation of a full-fledged fibrous tissue and adequate vascular proliferation, however, they prevented the preservation of the underlying peritoneum, which practically excluded its participation in the formation of the neoperitoneum. The REPEREN mesh and decellularized porcine peritoneum led to the least balanced cell and vascular proliferation and the greatest fibroplastic reaction, which could further negatively affect the state of the formed scar.