Impact of collagen subtype proportions in peritoneal tissues on inguinal hernia formation in adults and infants

Impaired collagen subtype proportions in the matrices results in the alteration of tissue tensile strength, and is an underlying cause of adult inguinal hernia formation; however, it remains unclear if this alteration is also responsible for infantile inguinal hernia formation. We correlated the ratios of collagen type I to type III between adults and infants with and those without an inguinal hernia, in an attempt to clarify the pathogenesis of this disorder. We extracted collagen from the hernial sacs of patients with an inguinal hernia, and from the normal peritoneum of patients without an inguinal hernia. After separation by electrophoresis, the collagen bands were quantified and we compared the ratios of collagen type I to type III between the patients with and those without an inguinal hernia. The ratio of collagen type I to type III was significantly lower in the adults with an inguinal hernia (n=8, 6.17±2.69) than in those without an inguinal hernia (n=8, 9.38±2.99, P=0.041), whereas the ratios were similar in infants with (n=10, 5.72±2.66) and those without an inguinal hernia (n=6, 5.60±1.88, P=0.925). Our results showed that tissue weakness was not involved in the pathogenesis of infantile inguinal hernia formation, confirming that simple herniotomy is adequate treatment.