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.