Contralateral groin exploration (CGE) in children with unilateral inguinal hernia remains controversial. Between January 2002 and December 2007, 1967 pediatric patients with inguinal hernia were treated by two surgeons with different criteria of CGE (group A; boys younger than 2 years, older boys prematurely delivered, and all girls, B; birth weight lower than 2kg with inguinal hernia presentation within 6 months after birth, and suspicious physical findings) at Samsung medical center. Patient's age, sex, body weight, diagnosis, and metachronous contralateral inguinal hernia (MIH) incidence were analyzed retrospectively. Among 895 patients in group A, CGE was performed in 460 patients (66.4%) and MIH incidence was 1.7%. In group B, 31 patients (3.5%) had CGE among 1072 patients, and MIH incidence was 4.2%. The average hospital costs of group A and B were 763,956 won and 500,708 won, respectively. The CGE criteria of group B had advantage in total hospital cost. The primary site and the age at presentation had a signiticant effect on the incidence of MIH. But MIH incidence was low and the more contralateral explorations lead to increase of total costs. Therefore, routine contralateral groin exploration and surgery for a patent processus vaginalis could not be justified.

Inguinal hernia is the most frequent problem requiring surgery in children. Moreover, subsequent contralateral occurrence after repair of the symptomatic unilateral inguinal hernia(UIH) is not rare. This study is to evaluate the diagnostic value of inguinal ultrasonography (IUS) for potential bilateral inguinal hernia(BIH). A prospective study was performed for preschool children less than 6 years of age who were diagnosed as UIH from July 1999 to December 2000. We selected 58 cases with potential BIH, based on the past history, such as prematurity, ventriculo-peritoneal shunt, family history of BIH, hernia on the left side (LIH), age below 2, female, and contralateral positive silk glove sign on the physical examination. Screening with IUS and bilateral surgical exploration were applied on these cases. Forty-seven cases were males (81.0%) and 11 cases were females(19.0%). Thirty-four were infants. Symptomatic right inguinal hernia (RIH) were 28 (48.3%), and LIH were 30 cases (51.7%). Six cases had no evidence of contralateral patent process vaginalis (PPV) by IUS but showed contralateral PPV by operation, Two cases were suspicious to contralateral PPV under IUS, but operative findings were negative. Fifty cases showed contralateral PPV by IUS as well as operation. The detection rate of contralateral PPV under IUS was 86.2%. The preoperative IUS may reduce contralateral exploration.

For the prevention of later contralateral hernia as well as unnecessary contralateral exploration in pediatric patients with unilateral inguinal hernias, a reasionable indication of contralateral exploration is required. To examine the contralateral positivity, a prospective selective contralateral exploration has been performed by the author from Sept. 1985 to Dec. 1993, at Pediatric Surgical Section of the Department of Surgery, Kangnam St. Mary's Hospital, Catholic University Medical College. Among the total 1200 cases of pediatric inguinal hernias, 580 cases of contralateral side were explored at hernia operations, by the indications as; 1)male with infant onset, 2)female of all age, 3)prematurity, 4)profuse ascites due to cirrhosis, nephrotic syndrome, and ventriculoperitoneal shunt, and 5)remarkable silk sign. Overall positive rate was 71.4%, and positive rates of each indication were 80.7%, 70.4%, 73.1 %, 66.7%, and 72.0%, respectively. Right side hernia showed 67.0%, left side 75.7%, and positive familial history 71.8% of contralateral positivities. In male,getting older revealed lower positive rates and the rate suddenly dropped after 12 years of age. Birth order, mother's age at delivery, postmaturity did not show any significant differences between the rates. Recurrence was seen in 3(0.5%) ipsilateral and 2(0.3%) contralateral, both of which were negative esplorations on previons operations. Overall complication rate was 3.8%, including 1 infection, 14 fluid or blood accumulation, 5 edemas, 3 temporary testicular edemas, 2 persisting fevers, 2 enuresis and one delayed recovery from anesthesia. Among 38 cases with contralateral hernias developed after unilateral surgery by authors(6 cases) or surgeons in other institutions, 14 were males with infant onset, 4 were prematurities and 9 were females. Therefore, 27(71.7%) cases were originaly under the contralateral exploration indications. The primary site of the hermia was right in 25 and left in 13. With above results, the following indications for contralateral exploration could be suggested; 1)under one year of age, both sex, 2)prematurity, 3)remarkable silk sign, 4)in the double checked suspicions among males with infant onset, all age females, ascites, left hernia and familial history. After 12 years of age, exploration is not required. Considering complications, contralateral explorations could be considered only in the following situations ; 1)expert, experienced pediatric surgeon, 2)experienced pediatric anesthesiologist, 3)operations could be done smoothly in an hour, 4)good general condition of the patient.