Incidence of chronic groin pain following open mesh inguinal hernia repair, and effect of elective division of the ilioinguinal nerve: meta-analysis of randomized controlled trials

Abstract

Chronic post-operative groin pain is a substantial complication following open mesh inguinal hernia repair. The exact cause of this pain is still unclear, but entrapment or trauma of the ilioinguinal nerve may have a role to play. Elective division of this nerve during hernia repair has been proposed in an attempt to reduce the incidence of chronic groin pain. We performed a meta-analysis of nine randomized controlled trials comparing preservation versus elective division of the ilioinguinal nerve during this operation. A substantial proportion of patients having open mesh inguinal hernia repair experience chronic groin pain when the ilioinguinal nerve is preserved (estimated rate of 9.4% at 6 months and 4.8% at 1 year). Elective division of the nerve resulted in a significant reduction of groin pain at 6-months post-surgery (RR 0.47, p = 0.02), including moderate/severe pain (RR 0.57, p = 0.01). However, division of the nerve also resulted in an increase of subjective groin numbness at this time point (RR 1.55, p = 0.06). At 12-month post-surgery, the beneficial effect of nerve division on chronic pain was reduced, with no significant difference in the rates of overall groin pain (RR 0.69, p = 0.38), or of moderate-to-severe groin pain (RR 0.99, p = 0.98) between the two groups. The prevalence of groin numbness was also similar between the two groups at 12-month post-surgery (RR 0.79, p = 0.48). Routine elective division of the ilioinguinal nerve during open mesh inguinal hernia repair does not significantly reduce chronic groin pain beyond 6 months, and may result in increased rates of groin numbness, especially in the first 6-months post-surgery.