Introduction. The long-term expected outcome after a hernia mesh repair is to create a framework in the prolapsed area that facilitates the development of mechanically robust, vascularized new tissue formations. Hernias of the anterior abdominal wall and vaginal prolapse are common and traditional suture repairs are associated with high rates of recurrence. Similarly, permanent meshes, while effective, often lead to significant patient morbidity in long term. For example, in Australia, transvaginal meshes were introduced in 2004 and unfortunately, while the meshes were successful in treating the prolapse, the material led to several serious complications, including pain and erosion into surrounding organs. Since 2017, most of these products have been removed from the market with worldwide litigation ongoing. To address the limitations of conventional permanent meshes, we developed 3D-printed biodegradable meshes with biomimetic mechanical properties and hypothesized that our medical-grade polycaprolactone (mPCL) scaffolds loaded with platelet-rich plasma (PRP), will enhance soft tissue regeneration in fascial defects in abdominal and vaginal sheep models.
Methodology. A pre-clinical evaluation of novel mPCL mesh scaffold concept for the vaginal and abdominal hernia reconstruction was undertaken along with the control of clinically-applied polypropylene (PP) meshes using an ovine model. Each sheep was implanted with both a PP mesh and a mPCL mesh loaded with PRP in both abdominal and vaginal sites for six months. Mechanical properties of the explanted tissue-mesh complexes were assessed with plunger tests. Tissue responses to the implanted meshes were evaluated via histology, immunohistochemistry and histomorphometry. Native fascial samples were also harvested from the animals for negative control comparison.
Results. The preliminary results obtained fromthis six month-long pilot study suggest that the surgical implantation of both grafts is safe. We could not find any signs of wound infection or graft erosion into the surrounding viscera. The explanted mPCL mesh/tissue complexes were measured to be less stiff than the PP mesh/tissue complexes, but stiffer than the native tissue, while showing equitable collagen and vascular ingrowth when compared to PP mesh/tissue complexes.
Conclusion. Our initial findings indicate that biodegradable mPCL scaffolds are safe and effective meshes for treating hernia and vaginal prolapse in short term (6 months), hence a full-scale long-term study (over 24-36 month) with an adequate sample size is recommended.