Role of biomarkers in incisional hernias.

Incisional hernias represent one of the most common complications of laparotomies. Previous investigations have suggested that a disorder in collagen fiber structure and production level may be an important pathologic cause of abdominal wall hernias. We hypothesized that a cross-examination of multiple extracellular matrix biomarkers might identify underlying defects contributing to the development of hernias. We examined two patient populations: patients with incisional hernias (presenting for hernia repair) and patients with no hernia after previous laparotomy (undergoing a second laparotomy). Patients with previous wound infections, open abdomens, or on steroids were excluded. Fascia samples were obtained from all patients at the time of their second operation and they were studied. Western blots and reverse transcriptase-polymerase chain reaction were used to determine the ratio of type I, III, and IV collagens, as well as matrix metalloproteinase 1 (MMP1) and MMP2 in both groups. Values of P < 0.05 were considered statistically significant. At the protein level, collagen I/III ratio was slightly decreased in patients with incisional hernias compared with those with no hernia, whereas it was significantly decreased at the mRNA transcript level (0.49 vs 1.03, P < 0.01, respectively). The MMP-1 mRNA transcripts were not different in incisional hernia (IH) versus nonincisional hernia, but the MMP-2 level was significantly increased in patients with IH. Reduced collagen I/III and MMP-1/MMP-2 ratios in IH might be consequence of the biological activities between key elements participating in the development of IH after laparotomies. The potential role of MMP-2-specific inhibitors in preventing IH is of significance for future studies.