Inguinal hernia in premature boys: should we systematically explore the contralateral side?

International audienceOBJECTIVE: Bilateral surgery has been largely advocated in premature boys with unilateral inguinal hernia owing to the high incidence of contralateral patent processus vaginalis. Recently, the potential morbidity of herniotomy in low birth-weight babies and the progress in pediatric anesthesia questioned this attitude. This study aims to evaluate the incidence of contralateral metachronous hernia in a large series of premature boys and to compare the morbidity of preventive versus elective surgery.METHODS: This retrospective multicenter analysis of 964 premature boys presenting with unilateral inguinal hernia operated from 1998 to 2012 included 557 infants who benefited from a unilateral herniotomy and 407 from a bilateral herniotomy (median follow-up 12months).RESULTS: Contralateral metachronous hernia after unilateral surgery occurred in 11% (n=60) without significant difference according to the initial symptomatic side (9.5% on right vs 13% on left, p>0.05). Postoperative morbidity on the contralateral side was higher after preventive surgery than elective surgery with metachronous hernia (2.45% versus 0.9%, p=0.05) especially for secondary cryptorchidism (1% vs 0%, p=0.03). Despite the risk of metachronous incarcerated hernia, elective surgery did not increase the rate of testicular hypotrophy on the opposite side (0.7%, vs 0.7%, p>0.05).CONCLUSION: Systematic bilateral herniotomy is unnecessary in almost 90% of patients and has a significant morbidity. Secondary surgery for metachronous hernia does not increase the risk of testicular lesion and even reduces the risk of secondary cryptorchidism. These results, along with the risk of hypofertility reported after bilateral surgery, may justify treating only the symptomatic side in premature boys.