[Resistance and biological tolerance of six "inert" parietal protheses. Experimental and critical study (author's...

Six different materials (3 mesh and 3 cloth) commonly used for the repair of abdominal wall hernias were evaluated in rats. 490 animals, distributed among four experimental groups, were implanted with one of the different prostheses through musculature and peritoneum. Serial macroscopic and bacteriological investigations were done. Using an original device, bursting strength of the wound was determined in all groups at intervals. Histological criteria were used to characterize the resistance of the wound and the tolerance of the host to foreign material. Statistical analysis of the results demonstrated that: 1) after the 15th post-operative day, the resistance of the wound was similar for each material tested; 2) during this early period mesh materials exhibited more resistance to bursting pressures than cloth materials; 3) the incorporation of mesh material was constant whereas encystment or extrusion was always observed after implantation of cloth material; 4) no infection occurred with mesh material but significant bacteria were found in 18 p. 100 of cloth material implantations; 5) the extent of the cellular reaction, the enumeration of giant, inflammatory cells and fibroblasts showed superiority of mesh material; 6) the ratio of fibroblasts/inflammatory cells reflected closely the mechanical resistance and tolerance of the foreign material.