Temporary sacral neuromodulation under local anaesthesia using new anatomical reference points

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.

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.

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.

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