Neurectomy to prevent persistent pain after inguinal herniorraphy: a prospective study using objective criteria to assess pain.

BACKGROUND: Although tension-free mesh repair has markedly improved the outcome of inguinal hernia surgery, it has only minimally reduced the incidence of persistent postoperative pain. The pathogenesis of this complication and treatment remain unclear. STUDY DESIGN: In order to objectively assess whether iliohypogastric neurectomy reduces the incidence and intensity of persistent postoperative pain, we prospectively studied 100 male patients with bilateral inguinal hernia who underwent tension-free surgical repair, combined with iliohypogastric neurectomy on the right side alone. Pain was evaluated postoperatively on days 1 and 7 and at 1 and 2 years by means of a visual analog scale. Patients were given a questionnaire including coded terms for describing pain. These terms were designed to compare pain on the neurectomized and non-neurectomized sides and assess altered sensation (hypoesthesia and paresthesia) on both sides. RESULTS: There were differences in the incidence and intensity of pain between the neurectomized and non-neurectomized sides, though these differences were not significant. Individual patient assessment showed that from postoperative day 7 onward patients had on average less pain on the neurectomized side. Pain reduction was more prominent in patients who scored 4 or more on the visual analog scale. No significant difference was found in the incidence of sensory alterations between the two sides. Two years after inguinal hernia repair, only one of the 100 patients studied still had persistent pain (>4 on the visual analog scale); this pain was on the non-neurectomized side. CONCLUSIONS: Our prospective data do not reach statistical significance to claim that iliohypogastric neurectomy reduces the incidence and intensity of persistent postoperative pain after tension-free inguinal hernioplasty. Studies on larger patient samples are warranted to provide definitive, statistically supported conclusions.