Polypropylene Surgical Mesh Implants for Hernia and Pelvic Floor Disorders: A Materials Performance Perspective

Surgical meshes are medical devices that were initially designed for hernia repair and later adopted for pelvic floor reconstructive surgeries, including pelvic organ prolapse (POP) and stress urinary incontinence (SUI). Polypropylene (PP) is the most common material for surgical mesh, but others have been used clinically. Complications with PP surgical mesh have been attributed to several factors, including the post-implantation degradation of the surgical mesh materials. PP mesh was initially considered to be inert, but evidence of in vivo degradation has since been widely reported in retrieved surgical mesh after long-term implantation. This review provides an overview of the physical and mechanical properties of surgical mesh prior to implantation and the post-implantation stability of the mesh materials. We underscore the need to consider the changes in mesh properties after implantation and their potential effects on device safety. This review highlights the importance of characterizing "effective porosity," assessing mechanical properties under physiological stresses, understanding the in vivo degradation mechanisms, employing accelerated bench-top aging methods to estimate long-term biostability, and developing in vitro in vivo correlations (IVIVC) to minimize resource-intensive long-term testing and improve patient access to innovative devices. Overall, this review provides a materials science perspective on the research gaps that could be considered in future iterations of surgical mesh devices to improve their safety and performance.