A Systematic Review on the Role of Matrix Metalloproteinases in the Pathogenesis of Inguinal Hernias

The recurrence rate in patients who undergo surgery for abdominal wall hernias (AWHs) is high. AWHs have been hypothesized to be a disease of the extracellular matrix, which is supported by evidence showing a high incidence of AWHs in patients with connective tissue disorders. This study aimed to investigate the most recent literature studies describing the levels of several matrix metalloproteinases (MMPs) in the blood and fascia, with the objective of better clarifying the pathogenetic role of matrix metalloproteinases (MMPs) and their inhibitors in inguinal hernias (IHs). A systematic literature search was conducted using the PubMed, Scopus, and Web of Science electronic databases to identify eligible studies. The identified studies were included in the analysis, and a qualitative synthesis of the results is provided to describe the most recent findings. Seventeen studies were included. An association between MMP-2 and direct IHs has also been demonstrated. MMP-1, MMP-2, MMP-9, MMP-12, and MMP-13 levels were increased in both the serum and fascia of patients with IHs. The analysis of inhibitors showed an increase in tissue inhibitors of metalloproteinases (TIMPs), specifically TIMP-1 in IHs, particularly in direct hernias, and a reduction in TIMP-2 in the biopsy samples of the transversalis fascia. In contrast, a reduction in TIMP-1 and an increase in TIMP-2 levels have been reported only in the serum of patients with IHs. Metalloproteinases play a crucial role in the pathogenesis of IHs. The analysis of other molecules, such as TIMPs or their correlation with specific genes, is enhancing our understanding of the pathophysiology of IHs. However, more prospective studies, including comprehensive clinical and laboratory data collection, are required to confirm the relationship between the studied biomarkers and the risk of IHs.