Is sacral nerve stimulation an effective treatment for chronic idiopathic anal pain?

Background: Chronic idiopathic anal pain is a common, benign symptom, the etiology of which remains unclear. Traditional treatments are often ineffective. This study investigated the efficacy of sacral nerve stimulation in treating chronic idiopathic anal pain.

Methods: Twelve patients (10 women and 2 men; mean age, 61.0 +/- 10.3 years; range, 48-82 years) implanted with a permanent device for sacral nerve stimulation were followed in the Italian Group for Sacral Neuromodulation (GINS) Registry. All patients had frequent chronic anal or perianal pain; 75 percent had previously undergone pelvic surgery. Pharmacologic and rehabilitative therapy had yielded poor results. Changes from baseline to last follow-up examination were evaluated for scores on a visual analog pain scale (0-10) and the Short-Form 36 (SF-36) health status questionnaire. Manometric measurements recorded at last follow-up were compared with preimplantation values.

Results: In one patient, the permanent device was removed because of technical failure. After a mean follow-up of 15 (range, 3-80) months, visual analog pain scores had significantly improved (from 8.2 +/- 1.7 to 2.2 +/- 1.3, P < 0.001). SF-36 physical component scores increased from 26.27 +/- 5.65 to 38.95 +/- 9.08, P < 0.02). Scores on the mental component showed improvement, although not significant. Postimplantation changes in manometric functional data were not significant, but sensitivity thresholds showed a considerable decrease.

Conclusions: Long-term follow-up data showing improvements in scores on the visual analog pain scale and quality of life questionnaire indicate that, before adopting more aggressive surgical procedures, SNS should be considered for patients with chronic idiopathic anal pain in whom pharmacologic and biofeedback treatments have failed to produce effective results.