Clinical outcome of sacral neuromodulation in incomplete spinal cord injured patients suffering from neurogenic lower urinary tract symptoms

Objective: To determine the efficacy and safety of sacral neuromodulation (SNM) in incomplete spinal cord injured (SCI) subjects affected by neurogenic lower urinary tract symptoms (NLUTS). Methods: Twenty-four SCI patients were enrolled. The individuals were divided into two groups: 13 individuals in the urinary retention category and 11 suffering from overactive bladder syndrome. All subjects underwent definitive SNM implantation (Medtronic, Inc.). Voiding symptoms were assessed using patient bladder diaries, which recorded both pre-SNM and before each follow-up (1, 3 and 6 months, and then every 6 months). Outcome measures were per 24 h: number of voids and voided volume per void for both groups; number of urinary leakages, pad use and nocturia for patients with overactive bladder syndrome; and volume per catheterization and number of catheterizations for urinary retention subjects only. Final checkups were completed by June 2008. Results: Median follow-up was 61 months. Up to the final visit, all subjects maintained a clinical improvement of more than 50% compared with baseline. Twenty-two side effects were recorded. Four subjects with urinary retention needed a new implant in the controlateral S3 sacral root because of loss of efficacy. One patient with urinary retention developed a wound infection at the implanted pulse generator site. Conclusions: Our study contains the largest series of implanted SCI patients ever published. SNM is a therapy to consider in the treatment of NLUTS for partial SCI patients, even if the loss of clinical benefits for patients with retentive NLUTS must be taken into account. All adverse events were treated effectively.