The incidence of positive contralateral inguinal exploration among preschool children--a retrospective and prospective study.

Retrospective and prospective studies were undertaken to evaluate the true incidence of bilateral inguinal involvement in preschool children in an established general pediatric population. Unbiased, anatomically based criteria were established for a "positive" exploration. It was found that bilateral inguinal involvement was highest during the first year of life (68%) and decreased through the advancing years, to just above 50% at 6 years of age. Because a widely patent processus vaginalis may be a precursor of indirect inguinal hernia, contralateral exploration may carry lifelong benefits in those who have the processus vaginalis ligated. Based on the authors' observations, contralateral exploration can be offered to all preschool children, and in selected cases (difficult preoperative preparation, anesthetic high risk, strong family history, etc), even beyond this age. Contralateral exploration is a safe, effective, and cost-wise practice when performed in an appropriate setting.