Comparison of tissue integration between polyester and polypropylene prostheses in the preperitoneal space.

Tissue integration and implant characteristics of various biomaterials commonly used for inguinal hernia repair have not been studied extensively. The aim of this study is to compare behavior and tissue response between two new polyester prostheses and a commonly used polypropylene (PP) mesh. The polyester prostheses utilized were polyester flat (PF) and polyester soft three-dimensional (PS); the PP mesh utilized was Marlex. Eight randomly assigned 4 x 4-cm2 pieces of two different meshes were fixed in the preperitoneal space with a centrally placed single suture. Gross evaluation included shrinkage and stiffness. Histological evaluation included amount of fibrous and fat encapsulation, connective tissue, foreign-body reaction, neovascularization, hemorrhage, necrosis, and exudate. Evaluations were graded on a zero to four scale. The area and the area ratio were measured using a calibrated micrometer. PP mesh resulted in more fibrous encapsulation and stiffness than PF and PS prostheses. PP also resulted in less connective tissue formation and foreign-body reaction than PF and PS prostheses. There was no difference in fat encapsulation, necrosis, hemorrhage, or exudate between prostheses. Both polyester prostheses (PF and PS) have better tissue integration than the PP mesh, as evidenced by the higher amount of connective tissue and lower extent of fibrous encapsulation.