Collagen Deposition and Inflammatory Response Associated with Macroporous Mesh Shrinkage in Incisional Hernia Repair: A Rat Model.

Background: Mesh repair is the current recommendation for the treatment of incisional hernia; however, the best mesh has yet to be determined. The objective of this study was to compare the inflammatory response and collagen deposition in primary incisional hernia repair (P) and different macroporous mesh materials, including polypropylene with poliglecaprone (PP-PG), polyvinylidene fluoride (PVDF), and polyester (PE), using quantitative methods. Methods: Sixty male rats were divided into four groups. Anterior abdominal wall defects were created and either suture or mesh repair was done. Rats were euthanized on days 14, 90, and 180, and the gross findings were recorded. The inflammatory and collagen levels in the abdominal wall tissues were measured using enzyme-linked immunosorbent assay (ELISA). Results: The PE group demonstrated significant mesh shrinkage at 180 days. The extent of PE mesh shrinkage ranged from 22-42% (mean = 30.49%). At 14 days, the PVDF group had higher interleukin-6 (IL-6) levels than the PP-PG ( P = .004) and PE groups ( P = .019). At 90 days, the collagen type I (Col I) levels in the PE group were significantly lower than those in the others, and the collagen type I/III (Col I/III) ratios in the PE group were lower than those in the P group ( P = .006). Conclusions: The persistently high IL-6 levels until 180 days and the decrease in Col I levels and Col I/III ratio at 90 days seem to predict mesh shrinkage at 180 days. The mesh induces high Col I levels, but those associated with low Col III levels should be preferred.