Tissue healing during degradation of a long-lasting bioresorbable gamma-ray-sterilised poly(lactic acid) mesh in the rat: a 12-month study.

Aim: The purpose was to evaluate soft-tissue healing after poly(lactic acid) (PLA(94)) mesh implantation in a rat model.

Methods: Full-thickness abdominal wall defects were created in 108 Wistar rats, and reconstructed with 83 PLA(94) and 25 lightweight polypropylene (PPL) meshes. The meshes were previously gamma-ray sterilised with 25, 75 or 125 kGy to accelerate PLA(94) degradation.

Results: The inflammatory response in PLA(94) was significantly less pronounced and collagen organisation significantly better than in PPL. The higher the level of gamma-radiation, the higher the incidence of abdominal wall herniation (22.2, 31.3 and 52.6% with 25, 75 and 125 kGy, respectively). No herniation occurred in the PPL group. Tensile strength was dramatically reduced after gamma-ray-sterilised PLA(94) mesh implantation.

Conclusion: The gamma-ray-sterilised PLA(94) mesh was poor in preventing abdominal wall hernia recurrences in a rat model.