Biochemical study of collagen in adult groin hernias

Background. Previous works have suggested that a defect in collagen fiber s tructure may play a role in inguinal hernia formation. These studies focuse d mainly on the rectus sheath or the skin, while only few reports dealt wit h the transversalis fascia. According to these findings and to our previous biomechanical and histological studies suggesting that a connective tissue pathology could play a role in the genesis of groin hernias, we performed a biochemical investigation of the collagen in the transversalis fascia and rectus sheath. Materials and Methods. The samples were collected from 40 adult patients wi th uni- or bilateral hernias and from 20 control subjects without hernia (a utopsies and organ donors). A constant area of tissue was taken by using a calibrator. The wet and dry weights per 100 mm(2) were determined and the t otal collagen concentration as well as its sequential extractibility in NaC l, acetic acid, and pepsin was measured. The ratios of alpha (1)/alpha (2), chains (I) and of type I/III collagen were assessed by polyacrylamide gel electrophoresis. Results. Samples collected in the control and patient sheaths showed an inc reased wet weight per 100 mm2 in the patients. The wet and dry weights per unit area were increased in the patient fascias. The collagen concentration was increased in the indirect hernias. The fascias from the direct hernias (DH) presented a significantly increased collagen extractibility after pep sin digestion (5.6%), when compared to the control fascias (2.6%). The extr actibility was 3.4% in the nonherniated (NH) sides. The qualitative study ( ratios alpha (1)/alpha (2) (I) and I/III collagen) showed no difference bet ween the fascia groups. Conclusions. The significant increase of collagen extractibility with pepsi n in the DH fascias and at a lesser degree in the NH fascias suggests that molecular alterations of collagen could be involved in the genesis of groin hernias. This connective tissue pathology would express preferentially its effects in the inguinal region, since we have observed no major difference between the rectus sheaths of controls and those of patients. (C) 2001 Aca demic Press.