Implantation of Sacral Nerve Stimulator

Abstract

Indication • Fecal incontinence Essential Steps Note: This procedure is usually performed in two stages. In Stage 1, a temporary stimulator is percutaneously placed. If the patient experiences > 50 % improvement of symptoms during a 2-week trial period, the temporary stimulator is exchanged for a subcutaneously implanted permanent one during Stage 2. Stage 1 1. Place patient in prone position. Keep patient awake for this stage of the procedure. 2. Prep the lower back/perineum, upper thighs, and buttocks. An adhesive iodine drape is used to allow visualization of the bellows response. 3. Identify the right and left third sacral fora-men using fluoroscopy with a C-arm (PA and lateral) and palpation of bony landmarks. Mark the overlying skin. 4. Administer local anesthesia and insert test needles through the marked skin at an angle of 60° with the skin surface. Advance needle under fluoroscopic imaging to the level of the sacral foramen. Verify optimal test needle placement. Insert the quadripolar lead under fluoroscopic guidance along the path of the test needle using Seldinger technique, until the most superficial electrode is in line with the anterior cortex of the sacrum. 5. Adjust the quadripolar lead in order to determine the most effective position (the position that elicits the best sensory/motor response with the least stimulating voltage). 6. After positioning the distal portion of the lead, tunnel the proximal end into a pocket under the gluteus fascia and connect to a temporary wire. This lead is tunneled to another site more lateral site where it is fixed to an external pulse generator. Stage 2 1. ≥50 % symptom resolution (as judged by either incontinence score or number of incontinent episodes per week) during a 2-week trial period using the temporary stim-ulator is an indication for implantation of a permanent device.