Histological, Immunohistochemical and Quantitative Analysis of Collagen in Patients with Direct Inguinal Hernia

Introduction: Abnormal collagen metabolism is thought to play an important role in the development of abdominal hernia. This is underlined by detection of altered collagen metabolism and structural changes of the tissues in patients with inguinal hernia. Aim of the Work: Was to study collagen synthesis defect in patients with direct inguinal hernia. Patients and Methods: Specimens were obtained from skin, transversalis fascia and sacs from forty two adult male patients with direct inguinal hernia and from 30 control adult patients without hernia during appendectomy. Sections from the specimens were stained with haematoxylin and eosin and Masson’s trichrome stains, for light microscope. Furthermore, immunohistochemical study for collagen type III and histological quantitative analysis of total collagen were done. Other specimens were processed for electron microscopic study. Results: Histological study of the tissues of patients with direct inguinal hernia revealed that the collagen fibers appeared loosely packed, widely separated and there was decrease in bundle formation. The immunohistochemical study showed an increase in type III collagen fibrils in comparison to that of controls. Also, there was a significant decrease in the amount of total collagen content compared to the control group. The electron microscopic study revealed degenerative changes in the fibroblasts associated with loosely packed collagen fibrils. These changes were detected in all studied tissues. Conclusions: We concluded that the substitution of collagen type I by collagen type III that has less tensile strength predisposes to development of direct inguinal hernia. We also concluded that inguinal hernia may be a local manifestation of a systemic disorder of collagen metabolism.