Special Feature

Surgical Management of Inguinal Hernia: Exploration of the Contralateral Side

By John Seashore, MD

What to do about the contralateral side in children with an inguinal hernia is an old and still controversial question, endlessly debated by pediatric surgeons. It is an issue because the primary cause of congenital indirect hernias is persistence of a patent processus vaginalis. When questioned, more than two-thirds of pediatric surgeons reported that they routinely explore the contralateral groin in both boys and girls.1 The processus remains patent in about 50% of infants and 30% of adults, so there is a large pool of males at risk for herniation but only a small percentage of these ever develop a clinical hernia. Conversely, if the processus is closed, there is no risk for an indirect inguinal hernia. There is no way to predict which patients will actually develop a contralateral hernia, so some surgeons routinely explore the opposite sides while others only operate on the affected side. Another approach is to identify which patients have a patent processus, usually by laparoscopy, so that only those children have a contralateral exploration. While most hernias in children are asymptomatic, are easily diagnosed by physical examination, and can be repaired with minimal morbidity as an outpatient, a small percentage of children, especially young infants, sustain considerable morbidity from incarceration and strangulation and from obstruction of the blood supply to the testicle, resulting in necrosis and atrophy. Children who have unilateral hernia repair, and then subsequently develop a contralateral hernia, incur the risk of a second general anesthetic and the additional cost and family stress of a second operation. Despite the thousands of children who have hernia repair every year, the best management has not been determined.

The vast majority of studies that have addressed this problem have been retrospective and suffer all the difficulties of that type of analysis. The ideal way to answer the questions would be a prospective study of 1000 or more children who have unilateral hernia repair and are then followed carefully for many years. A report by Tackett and colleagues describes a prospective study of 656 patients followed postoperatively for 6-40 months and is a good effort to attempt to resolve the issue. It is unlikely that there will be substantial numbers of new hernias beyond this period but the incidence will probably still increase, albeit slowly. The overall incidence of subsequent contralateral hernia was 8.8% and Tackett et al argue strongly that routine contralateral exploration is not indicated.

The major difficulty with the report of Tackett et al is the 16.5% incidence of synchronous bilateral hernias, which is far higher than in most reported series and in our experience. They state that the diagnosis of bilateral hernias was made by physical examination or reliable parental history but do not describe the criteria for diagnosis in detail. It is possible, perhaps even likely, that there was a bias toward exploration of the other side if there was any suggestion of a contralateral hernia. They found bilateral hernias in 28% of premature infants and 34% of infants younger than 6 months old. These age groups also had higher rates of subsequent hernia than the mean. A careful analysis of their data shows that, overall, 39% of preemies and 42% of infants younger than 6 months eventually proved to have bilateral hernias. They estimate that 50% of patients would have to have bilateral hernias in order for routine exploration to be cost effective. However, the cost analysis does not take account of the risk and emotional stress of a second operation.

This study and others have contributed to the trend away from routine contralateral exploration, which is appropriate in older children, but may not be for young infants. The risk of contralateral hernia is clearly greatest in the young age group and the risk of significant morbidity is also higher. Infants younger than 1 year of age may present with incarceration as the first sign of a hernia, whereas this is rare in older children. Physical examination for hernia is more difficult in infants and a hernia may be harder to reproduce and detect in the office setting, leading to delay in diagnosis. Thus, a case can still be made for routine contralateral exploration in young infants, former preemies, and, as noted in Tackett et al’s paper, children who present with an incarcerated hernia. The low incidence of contralateral hernias in all other patients, regardless of gender or age, may not justify routine contralateral exploration. Contralateral exploration should also be considered in children who have pulmonary disease or other conditions that may significantly increase the risk of anesthesia, such as cystic fibrosis, chronic pulmonary disease, or heart disease. Laparoscopy via the open sac or the traditional umbilical port is an option that may be preferred by some surgeons but there are no data that prove that this is superior to inguinal exploration. (Dr. Seashore is Professor of Pediatric Surgery at the Yale University School of Medicine and the Children’s Hospital at Yale-New Haven.)

References

1. Wiener ES, et al. Hernia survey of the section on surgery of the American Academy of Pediatrics. J Pediatr Surg 1996;31:1166-1169.

2. Tackett LD, et al. Incidence of contralateral inguinal hernia: A prospective study. J Pediatr Surg 1999; 34:684-688.

True statements concerning exploration of the contralateral groin in a child with an inguinal hernia include all of the following except:

a. is indicated when the patient is a young infant.

b. is indicated when the patient is a young child who was premature.

c. is indicated regardless of the age of the patient.

d. is indicated when there is incarceration at presentation.