Predictive Value of Tissue-induced Oxidative Stress on Urogynecology Synthetic Graft Reinforcement: An Experimental Animal Study

Abstract

Background: The success of urogynecology synthetic grafts depends on adequate tissue reinforcement. This experimental animal study aimed to determine the abdominal wall reinforcement achieved by different urogynecology synthetic grafts, including the influence of inflammatory cells, collagen deposits, and tissue-induced oxidative stress. Methods: Electron microscopic analysis of six different grafts, all with Polypropylene as their major component, was performed to determine the primary mesh characteristics. Full-thickness abdominal wall defects were repaired using monofilament, multifilament, and coated grafts in male Wistar rats. After six weeks, the animals were sacrificed and the inflammatory response, collagen deposition, and oxidative stress levels were quantified. Using the digital acquisition system (Hottinger Baldwin Messetechnik (HBM) “Catman Easy”, Darmstadt, Germany), mechanical testing of the native grafts and of the reinforced abdominal wall was conducted and measured in a controlled environment. Multivariate analysis was performed to determine the predictive value of inflammatory cell numbers, collagen amount, oxidative stress, and native graft strength on the final abdominal wall reinforcement. Results: The inflammatory response was significantly more prominent with the multifilament polypropylene compared to the low-weight monofilament polypropylene (p < 0.05). Collagen deposits varied between the groups, reaching statistical significance only for multifilament polypropylene vs. titanium-coated polypropylene (p < 0.05). The oxidative stress results demonstrated a positive correlation with graft weight, regardless of coating or different graft structures (p < 0.05). The number of inflammatory cells and collagen amount did not influence the final abdominal reinforcement, while tissue-induced oxidative stress presented with a negative influence in all groups. Conclusions: Tissue-induced oxidative stress negatively affected grafts in this animal experiment. This finding might be useful (at least partially) in predicting the effectiveness of urogynecology synthetic graft tissue reinforcement and also, in promoting this reinforcement.

Keywords

• inflammation
• mesh
• oxidative stress
• mechanical strength
• collagen quantification