Development of a porcine model for comprehensive in vivo and ex vivo evaluation of abdominal hernia meshes.

Abstract

<h4>Purpose</h4>There is a growing interest in developing new animal models to better understand the postoperative response of hernia meshes, which are key to improving device evaluation and clinical outcomes. This study presents an animal program using a porcine model to evaluate mesh response at the early postoperative period through in vivo imaging and and ex vivo pressure-based bench testing, comparing a lightweight flatsheet (LWF), a heavyweight flatsheet (HWF) and a self-fixating mesh (SFM).<h4>Methods</h4>Partially radiopaque meshes were implanted in vivo in twelve pigs. Two surgical models were compared: with and without open abdominal defect. CT scans were performed immediately and one week after surgery to assess the evolution of the mesh shape, position and defect size. Ex vivo porcine AW tissues were tested for mesh dislocation under repeated 250 mmHg cyclic pressure.<h4>Results</h4>In vivo, all meshes performed similarly on intact abdominal walls, while the SFM mesh demonstrated superior performance compared to LWF and HWF when implanted over an open defect without any fixation. SFM was associated with minimal adverse effects, whereas LWF and HWF frequently led to poor integration, seroma formation and mesh dislocation into the defect. Ex vivo pressure testing exhibited similar trends: SFM provided better repair protection, while LWF-and to a lesser extent HWF-exhibited progressive migration/dislocation into the defect and defect enlargement under pressure, which reduced mesh overlap and ultimately resulted in total mesh dislocation.<h4>Conclusion</h4>This preclinical program could serve as a standardized and reproducible framework, enabling comparison of new mesh designs based on their sensitivity to known modes of failure.