Preoperative sonographic evaluation is a useful method of detecting contralateral patent processus vaginalis in pediatric patients with unilateral inguinal hernia

Abstract

Background/purpose To analyze the value of ultrasound scan (US) in the preoperative identification of a contralateral patent processus vaginalis (CPPV), the authors investigated the presence of CPPV by US in children with clinically diagnosed unilateral inguinal hernias. Methods Three hundred forty-eight patients (168 boys and 180 girls) with unilateral inguinal hernia underwent US examination using a 7.5-MHz linear transducer. If a CPPV was visible as a hydrocele owing to the inflow of physiologic ascites into a processus vaginalis on straining, then US scanning was performed while the patient was at rest and while inducing straining by standing or crying. A groin with a hydrocele in the inguinal canal on straining was diagnosed as a CPPV and was explored bilaterally through surgery. The US findings were compared with surgical results. Results In 348 patients, 78 cases (22.4%) were diagnosed by US as patients with a CPPV; these patients underwent bilateral surgery. Seventy-four of 78 cases (94.9%) were confirmed surgically as patients with CPPV. Conclusions A CPPV was detected correctly by US in 74 of 348 patients (21.3%) with clinically diagnosed unilateral inguinal hernias. US is a noninvasive and accurate method for evaluating the presence of a CPPV.