Morphologic Evaluation of Post-implanted Monofilament Polypropylene Mesh Utilizing a Novel Technique with Scanning Electron Microscopy Quantification.

Polypropylene mesh has been shown to shrink up to 50%; however, little is known about other changes that may occur while it is implanted. It is unclear whether such changes have clinical impact; nonetheless, knowledge of such can ultimately affect the technique of implantation and may affect outcomes. The objective of this study was to evaluate surgically explanted mesh after two years implantation for evidence of change in morphology using scanning electron microscopy (SEM). Secondly, we describe a novel technique for quantifying such changes with intentions for future validation. SEM imaging was conducted and mesh changes were visualized. SEM images revealed deep surface cracks both transverse and longitudinal, flaking and peeling of fibers, as well as fibrosis. Microstructural quantification of cracks was also completed. The fraction of transverse cracked area to whole surface area was 24.2%. Average crack length range was 0.58 to 71.46 µm and average crack thickness range was 0.99 to 25.46 µm. Polypropylene mesh is subject to structural changes after surgical implantation. It is important to investigate how these processes impact clinical outcomes. Validated techniques of quantifying such changes can prove useful in future research and aid in development of the ideal graft.