The Characteristics of the Contralateral Inguinal Internal Ring and Hernia Sac by Transinguinal Laparoscopy in Boys with Unilateral Indirect Inguinal Hernia: Analysis of Risk Factors and Associated Features with Metachronous Development

Abstract

Purpose: We evaluated the contralateral patent processus vaginalis (CPPV) by transinguinal laparoscopy in boys with unilateral inguinal hernia, to determine its incidence and the association with various clinical parameters. We also investigated the factors responsible for the development of a metachronous inguinal hernia. Materials and Methods: One hundred sixty seven boys with unilateral inguinal hernia were analyzed. The morphology of the ring was classified into four patterns (type 1, 2a, 2b, and 3). We analyzed the morphology of the internal ring and the variables related to a CPPV by age, laterality and the size of the ipsilateral and/or bilateral hernia sac. Results: The incidence of a CPPV was 33.9%. The positive predictive value was 94.9% (56/59). There was no statistical difference in the incidence of a CPPV by laterality. The incidence of a CPPV was significantly higher in the group with a larger size (≥1cm) compared to the smaller abnormalities (<1cm). The incidence of the type 3 pattern was higher than the type 2b pattern in the group with larger abnormalities. With increasing age, type 1 and 2a patterns increased in frequency, but type 2b decreased and the type 3 pattern was stable. The size of the contralateral hernia sac was significantly larger with the type 3 pattern than the type 2b. Conclusions: The results of our study showed that the size of the hernia sac and patient age were related to the presence of a CPPV. A type 3 pattern was associated with a more primitive morphology, a wider hernia sac and no change in the incidence with advancing age. Therefore, the findings of this study suggest that a metachronous inguinal hernia develops more commonly in patients with a type 3 pattern internal ring. (Korean J Urol 2007;48:735-740) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏