Behaviour at the peritoneal interface of next-generation prosthetic materials for hernia repair

Fully resorbable poly-4-hydroxybutyrate (P4HB) mesh for soft tissue repair and reconstruction: A scoping review

Background

Poly-4-hydroxybutyrate (P4HB) is a fully resorbable, biologically-produced polymer with a strength and flexibility comparable to permanent synthetic polymers. The objective was to identify/summarize all peer-reviewed publications involving P4HB mesh.

Methods

A scoping review was conducted within PubMed and included articles published through October 2022.

Results

A total of n = 79 studies were identified (n = 12 in vitro/bench; n = 14 preclinical; n = 6 commentaries; n = 50 clinical). Of the clinical studies, n = 40 reported results applicable to hernia and n = 10 to plastic/reconstructive surgery and involved patients of all Centers for Disease Control (CDC) wound classes and Ventral Hernia Working Group (VHWG) grades.

Conclusion

P4HB mesh provides long-term hernia repair strength and exhibits promising clinical outcomes beyond its resorption period. Future studies should include randomized controlled trials comparing P4HB to other biomaterials, as well as optimal patient selection, operative technique, long-term outcomes, minimization of potential mesh-related complications, and potential contraindications/complications for P4HB in hernia/abdominal wall reconstruction.

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

OBJECTIVE

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.

MATERIAL AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Construction and properties of the silk fibroin and polypropylene composite biological mesh for abdominal incisional hernia repair

Background: In this study, a new composite biological mesh named SFP was prepared by combining silk fibroin with polypropylene mesh. The mechanism and clinical application value of the SFP composite mesh were explored.

Methods: The fibrous membrane was prepared by electrospinning of silk fibroin. The silk fibrous membrane was adhered to the polypropylene mesh by fibrin hydrogel to make a new composite mesh. The characterizations were verified by structural analysis and in vitro cell experiments. A total of 40 Sprague–Dawley rats were randomly divided into two groups, and 20 rats in each group were implanted with the SFP mesh and pure polypropylene mesh, respectively. The rats were sacrificed in batches on the 3rd, 7th, 14th, and 90th days after surgery. The adhesion degree and adhesion area on the mesh surface were compared, and a histopathological examination was carried out.

Results:In vitro cell function experiments confirmed that the SFP mesh had good cell viability. The control group had different degrees of adhesion on the 3rd, 7th, 14th, and 90th days after surgery. However, there was almost no intraperitoneal adhesions on the 3rd and 7th days after surgery, and some rats only had mild adhesions on the 14th and 90th days after surgery in the SFP group. There were statistically significant differences in the postoperative intraperitoneal adhesion area and adhesion degree between the two groups (p < 0.05). Histopathological examination confirmed that the mesenchymal cells were well arranged and continuous, and there were more new capillaries and adipocyte proliferation under the mesenchymal cells in the SFP group.

Conclusion: The SFP mesh shows good biocompatibility and biofunction in vitro and in vivo. It can promote the growth of peritoneal mesenchymal cells. The formation of a new mesenchymal cell layer can effectively reduce the extent and scope of adhesion between the mesh and abdominal organs. The SFP mesh will have a good application prospect in the field of abdominal wall hernia repair.

Polymer Hernia Repair Materials: Adapting to Patient Needs and Surgical Techniques

Biomaterials and their applications are perhaps among the most dynamic areas of research within the field of biomedicine. Any advance in this topic translates to an improved quality of life for recipient patients. One application of a biomaterial is the repair of an abdominal wall defect whether congenital or acquired. In the great majority of cases requiring surgery, the defect takes the form of a hernia. Over the past few years, biomaterials designed with this purpose in mind have been gradually evolving in parallel with new developments in the different surgical techniques. In consequence, the classic polymer prosthetic materials have been the starting point for structural modifications or new prototypes that have always strived to accommodate patients’ needs. This evolving process has pursued both improvements in the wound repair process depending on the implant interface in the host and in the material’s mechanical properties at the repair site. This last factor is important considering that this site—the abdominal wall—is a dynamic structure subjected to considerable mechanical demands. This review aims to provide a narrative overview of the different biomaterials that have been gradually introduced over the years, along with their modifications as new surgical techniques have unfolded.