The development of metachronous contralateral inguinal hernia after unilateral inguinal hernia repair in infants and children

Background Pediatric Inguinal hernia is the most common surgical procedure in infants and children with a rate of 1–5% in full-term infants. The male-to-female ratio is 5: 1. In Some children with unilateral inguinal hernia, a contralateral one may appear later known as a Metachronous Contralateral Inguinal Hernia (MCIH). Aims To determine the incidence and risk factors of MCIH development in infants and children and the necessity of routine contralateral side exploration. Patients and methods This was a prospective study that was carried out on 217 infants and children presented with a unilateral inguinal hernia. All children were subjected to ultrasonography of the inguino-scrotal region at the first presentation and a second ultrasonography was done with the appearance of a metachronous hernia. Results Increase the risk of developing a MCIH in patients with unilateral inguinal hernia with an age below 6 months, low birth weight (≤2000 gm), immaturity, patients with contralateral internal ring diameter at the primary presentation above or equal 4 mm, and the presence of an umbilical hernia. The side of the ipsilateral hernia and the sex of the patients have less effect on the development of a MCIH. Therefore, a score was built depending on these risk Factors. Conclusions The incidence of MCIH development after unilateral hernia repair in this study was 12%. A debate is still present regarding exploring the contralateral side after unilateral inguinal hernia repair.