Interposition of polyglactin mesh does not prevent adhesion formation between viscera and polypropylene mesh

BACKGROUND: The use of intra-peritoneal polypropylene mesh (PPM) to repair incisional hernia carries the risk of adhesions and damage to the intra-abdominal viscera. Polyglactin 910 mesh (PGM) is advocated to avoid contact between PPM and the intra-abdominal viscera. An experimental study in rats was performed to determine if interposition of a resorbable prosthesis between the PPM and viscera alters biocompatibility, adhesion formation, and herniation. MATERIALS AND METHODS: A 2- x 3-cm abdominal wall defect was created in 80 rats. Rats were randomly assigned for repair with 2.5- x 3.5-cm PPM (n = 40) or 2.5- x 3.5-cm PPM plus polyglactin 910 mesh (PPM-PGM) (n = 40). The rats were sacrificed at 1, 2, 3, and 6 months (n = 10), and an autopsy was performed to determine herniation and adhesion rates. Mesh-fascia interface was taken for histology. RESULTS: In the PPM group, 1 rat died before the end of the experiment, and at 6 months one of the 10 rats had a herniation. In the PPM-PGM group, two rats died before the end of the experiment, and two rats had a herniation after 1 month and three rats after 6 months. At 1, 2, and 3 months the adhesion score in the PPM group (median, 3; range, 2-3) did not differ from the score in the PPM-PGM group (median, 3; range, 2-3). Also, at 6 months the adhesion score in the PPM group (median, 2; range, 2-3) did not differ from the score in the PPM-PGM group (median, 3; range, 2-3). At microscopy a capsule was formed around the PP fibers, which matured over months in the PPM group. In the first month after implantation an inflammatory response was seen. Histology was similar in both groups, although in the early PPM-PGM group the inflammatory response was more evident. CONCLUSION: Interposition of PGM between PPM and viscera does not alter adhesion formation nor influences herniation rate.