Tailored laminectomy: A new technique for neuromodulator implantation

Purpose: Neuromodulation of sacral roots is an alternative mode of therapy for patients with urge incontinence or detrusor hypocontractility. We inves tigated the effects of sacral (S3) nerve stimulation in patients using a ne w surgical approach for sacral neuromodulator implantation. Modification of the implantation method with sacral laminectomy and bilateral electrode pl acement led to distinct improvement of stimulation, positioning and disloca tion. We developed tailored laminectomy for bilateral neuromodulator electr ode implantation to minimize surgical trauma. Materials and Methods: Tailored laminectomy was performed in 6 patients wit h urge incontinence and 3 with a hypocontractile detrusor. After making a 1 0 cm. longitudinal skin incision we exposed the spinous processes of S2 and S3. Instead of complete 2-level laminectomy, only 2 oval laminectomy holes were made with a high speed ball drill. An electrode fixation hole was dri lled at the edge of the laminectomy window and the wire was fixed with nona bsorbable suture material. Results: In patients with idiopathic urge incontinence (followup 12.5 month s, range 7 to 18) the number of leaks decreased from 7.2 to 0 daily and fun ctional bladder capacity increased from 298 to 352 ml. In patients with a h ypocontractile detrusor (followup 10.5 months, range 6 to 20) detrusor pres sure increased during voiding from 12 to 34 cm. water and post-void residua l decreased from 350 to 58 mi. Average surgery time was 2 hours 15 minutes. In 1 case a seroma developed near the impulse generator. Conclusions: Tailored laminectomy is a fast, minimally invasive and reliabl e technique for neuromodulator implantation.