Back to 2014 Fall Congress Meeting Abstracts

BACKGROUND: Sacral nerve stimulation (SNS) via an implantable pulse generator is an FDA approved second line option for adults with overactive bladder symptoms refractory to medical treatment. Currently in the United States, there have been less than 500 sacral nerve stimulators implanted in children under the age of sixteen years. We present a series of 16 children with refractory voiding dysfunction who have had good subjective and objective response to SNS.
METHODS: All patients who underwent placement of a permanent SNS are followed prospectively in our IRB-approved SNS Patient Registry. Patients were evaluated for SNS placement when they demonstrated any of the following: UDS evidence of detrusor overactivity (DO), high post-void residual (PVR), and failure of anticholinergic medications or biofeedback therapy. Exclusion criteria included abnormal genitourinary anatomy or previous urologic reconstructive surgery. Most patients underwent a two-stage procedure under general anesthesia; one patient underwent a single stage procedure. The first stage was placement of a permanent SNS lead with a temporary external generator. If symptoms subjectively improved more than 50% after several weeks, placement of permanent SNS was performed. Within a prospective longitudinal database, we collected clinical information including demographics, comorbid conditions, past and current treatments, patient reported outcomes including the Vancouver Dysfunctional Elimination Syndrome Symptom Score, and objective measurements of bladder function including UDS.
RESULTS: Sixteen patients (13 females) with a mean age of 10.3 years (range 7-17 years) underwent permanent SNS placement between 2012 and 2014. Median follow-up was 25.6 weeks (interquartile range: 14.8, 32.0 weeks). Indications for SNS placement included refractory urinary incontinence and DO (n=12), or urinary retention requiring clean intermittent catheterization (CIC) (n=4). In the group with primary DO, eleven patients (92%) had subjective improvement in urgency or urge incontinence. Of 7 patients still on anti-cholinergic medications at the time of surgery, 71% discontinued medication by the time of post-operative UDS due to symptom improvement. Median Vancouver scores have significantly improved, from 22.5 (17.8, 27.0) prior to SNS placement to 13 (8, 18.8) (p=0.001). Three of ten patients with DO demonstrated on UDS had resolution of DO on post-SNS UDS. Four additional patients had marked improvement in the amplitude and frequency of uninhibited detrusor contractions post-SNS. The remaining three patients had unchanged UDS. Patients in the urinary retention group decreased their post void residuals after SNS on average by 77.8%; mean 765.25 mL reduced to 235.5 mL post-operatively (p = 0.15). Two patients have been safely able to decrease their daily frequency of CIC and one has safely stopped CIC altogether. Two patients required explant of SNS for wound infection. Both patients subsequently underwent replacement of SNS.
CONCLUSIONS: This series demonstrates subjective and objective improvements in children who have undergone permanent SNS placement for refractory urinary dysfunction, including DO and urinary retention. As additional patients undergo SNS placement and follow-up of existing patients continues, we will be able to better determine the long-term efficacy and outcomes of SNS for this challenging subset of children with bladder and bowel dysfunction.