Predictive factors of stress incontinence after posterior sacral rhizotomy

The Brindley procedure, used since the 1980s, consists of implantation of a stimulator for sacral anterior root stimulation combined with a posterior sacral rhizotomy to enable micturition. Patients suitable for the procedure are patients with detrusor overactivity and a complete spinal cord lesion with intact sacral reflexes. S2 to S4 posterior sacral rhizotomy abolishes sacral hyperreflexia and may lead to decreased urethral closure pressure and loss of reflex adaptation of continence, leading to stress incontinence.

In this retrospective study of 96 patients from Nantes or Le Mans, implanted with a Finetech-Brindley stimulator, we analyzed the incidence of stress incontinence one year after surgery and looked for predictive factors of stress incontinence one year after posterior sacral rhizotomy: age, gender, level of injury between T10 and L2 , previous urethral surgery, incompetent bladder neck, Maximum Urethral Closure Pressure before surgery less than 30 cmH2 O, compliance before surgery less than 30 ml/cmH2 0. Patients with persistent involuntary detrusor contractions with or without incontinence after surgery were excluded.

One year after surgery, 10.4% of the patients experienced stress incontinence. Urethral closure pressure was significantly decreased by 18% after posterior sacral rhizotomy (P = 0.002). This study highlights the only significant predictive factor of stress incontinence after rhizotomy: incompetent bladder neck (P = 0.002).

As screening of patients undergoing the Brindley procedure is essential to achieve optimal postoperative results, on the basis of this study, we propose preoperative assessment to select the population of patients most likely to benefit from the Brindley procedure.