Sacral nerve stimulation for faecal incontinence: response rate, satisfaction and the value of preoperative investigation in patient selection

Objective Before undergoing sacral nerve stimulation (SNS) for faecal incontinence (FI), patients are investigated with morphologic, dynamic and electrophysiologic tests. The purpose of our study was to evaluate their value in the selection of patients who may benefit most from neuromodulation. Method If temporary stimulation resulted in a good objective response, a permanent neuromodulator was implanted. Patients were reviewed at 3 months and then at 6 monthly intervals. Asked by telephone, patient's satisfaction was described as good, satisfactory or poor. Results Forty-five consecutive patients (41 females, median age 59 years) with FI (Wexner 16.1 +/- 2.9) underwent SNS. Temporary stimulation was successful in 32 (71)% patients. At a median follow-up of 33 months, the neuromodulator remained in place in 25 (55%) patients, two do whom switched it off, leaving 23 (51%) with a functioning neuromodulator. There was no statistically significant difference between the characteristics (including manometry, ultrasound and electrophysiology) of patients undergoing implantation (n = 32) or not (n = 13) and those with or without a functioning stimulator (n = 23: n = 13). In the 23 patients with a functioning stimulator the result was good in 12, satisfactory in five and poor in six. There was no statistically significant difference in the patient characteristics between those with a good result (n = 12) and the remainder (n = 32). Conclusion The findings suggest that investigation for FI does not facilitate patient selection for SNS and cannot be used to predict outcome.