Comparison of the levels of metalloproteinases and their tissue inhibitors in serum and fascia in four methods of midline laparotomy closure: standard, small bites, reinforced tension line and onlay mesh (absorbable and non-absorbable). Experimental

Abstract Incisional hernia (IH) is a major complication following laparotomy. IH significantly impacts healthcare costs and patient quality of life. Current strategies to prevent IH focus on optimizing abdominal wall closure techniques, and the use of meshes. Matrix metalloproteinases (MMPs) and their inhibitors [tissue inhibitors of metalloproteinases (TIMPs)] play a critical role in extracellular matrix remodeling and wound healing, and their imbalance may contribute to hernia formation. This study aims to compare MMP and TIMP levels across five closure techniques to identify the most effective approach for promoting optimal wound healing. An experimental, prospective and longitudinal study will be conducted using 40 male Wistar rats randomized into five groups: standard closure, small bites, reinforced tension lines, absorbable onlay mesh and non-absorbable onlay mesh. Surgical procedures will be standardized, and samples will be collected at three time points: pre-surgery, 10 min post-surgery and 60 days post-surgery. MMP and TIMP levels will be quantified in serum and fascial tissue. Statistical analysis will include descriptive statistics, normality tests and group comparisons using ANOVA or non-parametric tests, with a significance threshold of P < 0.05. The study adheres to ARRIVE 2.0 guidelines.The study has been approved by the ethics committees. All procedures comply with Mexican and international guidelines for the ethical use of laboratory animals. Results will be disseminated to healthcare professionals, researchers and policymakers to inform clinical practices and improve surgical outcomes. Findings will also be shared with patient advocacy groups and presented at conferences to promote evidence-based approaches to IH prevention.