Temporary sacral neuromodulation under local anaesthesia using new anatomical reference points

Background: Prior to implantation of an expensive sacral nerve stimulator, a ‘screening phase’ is undertaken. This report examines the feasibility of temporary sacral neuromodulation under local anaesthesia in an outpatient setting. We report on our technique, results and patient satisfaction.

Methods: Percutaneous nerve evaluation was performed in 184 patients using a new set of reference points and local anaesthesia to guide insertion of a test wire without the need for fluoroscopy in an outpatient setting. Three bony landmarks were used: tip of the coccyx, sacro-coccygeal joint and posterior superior iliac spine. The technical success was defined as stimulation in the perineal/anal area at amperages <6 mAmp. A consecutive cohort of 24 patients was asked to grade their pain and satisfaction regarding the procedure.

Results: Successful placement of the test wire was accomplished in 171 patients (93 %). Twelve patients required placement under fluoroscopy due to lack of sensation during stimulation (N = 7) procedural pain (N = 4) or failure to identify S3 or S4 (N = 2). There were two lead infections, one lead dislocation and one lead fracture. 22 of 24 patients (92 %) would recommend the procedure under local anaesthesia to other patients.

Conclusions: Temporary sacral neuromodulation can be reliably performed in a more practical, less expensive outpatient setting under local anaesthesia without adversely influencing test outcome.