Quantitative analysis of collagen and elastic fibers in the transversalis fascia in direct and indirect inguinal hernia.

PURPOSE Our previous studies demonstrated structural and quantitative age-related changes of the elastic fibers in transversalis fascia, which may play a role in inguinal hernia formation. To verify whether there were differences in the extracellular matrix between direct and indirect inguinal hernia, we studied the amount of collagen and elastic fibers in the transversalis fascia of 36 male patients with indirect inguinal hernia and 21 with direct inguinal hernia. MATERIAL AND METHODS Transversalis fascia fragments were obtained during surgical intervention and underwent histological quantitative analysis of collagen by colorimetry and analysis of elastic fibers by histomorphometry. RESULTS We demonstrated significantly lower amounts of collagen and higher amounts of elastic fibers in transversalis fascia from patients with direct inguinal hernia compared to indirect inguinal hernia patients. The transversalis fascia from direct inguinal hernia patients showed structural changes of the mature and elaunin elastic fibers, which are responsible for elasticity, and lower density of oxytalan elastic fibers, which are responsible for resistance. These changes promoted loss of resiliency of the transversalis fascia. CONCLUSION These results improve our understanding of the participation of the extracellular matrix in the genesis of direct inguinal hernia, suggesting a relationship with genetic defects of the elastic fiber and collagen synthesis.