Is Preoperative Ultrasonography Necessary in Pediatric Inguinal Hernia

Purpose: Preoperative ultrasonography (USG) in pediatric inguinal hernia has controversy. In this study, we analyzed the cases of pediatric inguinal hernia with/without preoperative USG and discussed whether USG is necessary. Methods: We reviewed medical records of 1,441 patients who underwent inguinal hernia repair in Seoul National University Children’s Hospital between January 2011 and August 2016 retrospectively. Results: Male were 69.3% and age at operation was 37.8±36.5 months old. There were 150 patients (10.4%) performed USG preoperatively. The department ordered to perform USG included department of surgery (n=71), emergency medicine (n=42), pediatrics (n=26), urology (n=10) and outside hospital (n=1). The reasons of performing USG included evaluation for hernia laterality (n=82), incarceration (n=28), testis (n=15), request of parents (n=14), scrotal mass (n=6) and incidentally found during evaluation for another disease (n=5). Excepting 5 cases of incidental finding, of 145 cases with USG, 12 (8.3%) cases changed the surgical plan; change to bilateral repair from unilateral repair (n=5), emergency operation due to incarceration (n=4) which include 1 salpingo-oophorectomy, 1 open abdomen surgery and 2 hernia repair after reduction of ovary, change to co-operation of orchiopexy (n=2) and change to laparoscopic surgery from open surgery due to herniation of both ovaries into one inguinal canal (n=1). In group without USG (n=1,291), 5 patients (0.4%) had unexpected problems during operation; 2 co-operation of orchiopexy because of transverse testicular ectopia (n=1) and right undescended testis (n=1), 2 hypertrophy of major labia and 1 retroperitoneal lymphangioma at inguinal area misdiagnosed as inguinal hernia. Conclusion: It was difficult to interpret the meaning of preoperative USG because not all patients had performed it. In this study, 10.4% of patients performed USG and 8.3% of them changed surgical plan. About 0.4% of patients without preoperative USG would have benefited from it for surgery if they had performed it. Since the percentage is too low, it is unreasonable to conclude that USG has diagnostic utility in inguinal hernia in this study.