[Continuous bilateral sacral neuromodulation as a minimally invasive implantation technique in patients with functional bladder changes]. / Neuromodulación crónica sacra bilateral con una técnica de implantación mínimamente invasiva en pacientes con alteraciones funcionales de la vejiga.

OBJECTIVE: Up to 50% of patients with bladder dysfunctions undergoing sacral neuromodulation treatment are non-responders. The most common treatment method today is the implantable neuromodulation system described by Tanagho and Schmidt; which allows unilateral sacral nerve stimulation. Our aim was to increase the number of responders and to improve the general efficiency of chronic sacral neuromodulation; therefore we have developed the bilateral electrode implantation by minimally invasive laminectomy. METHODS: PNE-tests were carried out to assess which patients were likely to be good responders. Thirty patients (16 with detrusor instability, 14 with hypocontractile detrusors) were subjected to minimally invasive laminectomy and received implants of bilateral electrodes. RESULTS: In those patients with a hyopcontractile detrusor, the level of residual urine of initially 350 ml was reduced to 58 ml, and the maximum detrusor pressure during micturition increased from initially 12 cMH2O to 34 cmH2O. In the other patient group with detrusor instability, the average number of incontinence incidences could be reduced from initially 7.2 to 1 per day, while the bladder capacity rose from 198 ml to 348 ml. The modulation effect did not show any signs of deteriorating in any of the patients. The follow-up period was 28 months on average. CONCLUSIONS: Clinical experience has shown that optimal neuromodulation in patients with bladder dysfunction can be achieved by this new approach involving bilateral electrode implantation. Moreover, the laminectomy implantation method guarantees a minimum of invasive trauma and enables optimal placement and fixation of the electrode.