Long Term Outcomes of Sacral Neuromodulation: A 23-year experience

Gandhi S1, Almutairi S1, Ali A1, Cox A1, Gajewski J1

Research Type


Abstract Category

Female Lower Urinary Tract Symptoms (LUTS) / Voiding Dysfunction

Abstract 437
Scientific Podium Short Oral Session 22
Thursday 30th August 2018
14:45 - 14:52
Hall A
Urgency Urinary Incontinence Painful Bladder Syndrome/Interstitial Cystitis (IC) Mixed Urinary Incontinence Neuromodulation Retrospective Study
1. Dalhousie University

Shreyas Gandhi



Hypothesis / aims of study
Sacral Neuromodulation (SNM) has been found effective for the treatment of ”dry and wet” overactive bladder (OAB), Bladder Pain Syndrome/interstitial cystitis (BPS/IC) and voiding dysfunction (VD). Our department was one of the first two in Canada that started SNM treatment in 1994. Several studies show the safety and efficacy of SNM at short- and medium- term follow-up [1][2][3]. In this study, we review the long-term outcomes and complications of SNM treatment for any indication.
Study design, materials and methods
This was a retrospective study of all patients who underwent test phase (peripheral nerve evaluation- PNE and/or 1st stage procedure) and then SNM by a single surgeon from 1994 – 2017. The primary outcome was to assess long-term outcomes of SNM using the global response assessment scale. This included percent improvement in pain, as well as storage lower urinary tract symptoms (urinary frequency, urgency, urge incontinence, and nocturia), and voiding lower urinary tract symptoms (weak stream, hesitancy, intermittency, straining and bladder emptying). Secondary outcomes included number of revisions, reason for revision, complications and rate of device removal.
Total of 434 patients were included with 373 (86%) female and 61 (14%) male patients. All patients underwent Test Phase and 241/435 (55%) patients eventually received a SNM implant. Mean age at time of implant was 49 years. Of the patients that received SNM implant, 118 (49%) had a diagnosis of BPS/IC, 24/241 (10%) with VD, 86/241 (36%) with OAB, and 13/241 (5%) with neurogenic lower urinary tract dysfunction (NLUTD).  Mean follow-up time was 5.8 years (1 month–20.5 years). 76/241 (32%) devices were removed due to device failure or complication. 167/241 (69%) patients underwent at least one follow-up surgical revision [Figure 1]. The mean percentage improvement in symptoms on the last follow-up (mean 6.4 years) for patients with successful SNM was 69%. At the end of data collection, 166/241 (69%) devices remained in-situ with ongoing follow-up [Figure 2].
Interpretation of results
This retrospective study provides valuable insight due to the long-term follow-up. Moreover, we now have a better understanding of the common complications and rate of these complications that patients experience in the long run. Lastly, a mean improvement of 69% in symptoms highlights the serious consideration that SNM needs to be given by Urologists when looking for options for patients with a variety of different urologic concerns.
Concluding message
Traditionally patients with OAB, VD and IC, who failed conservative measures were left only with highly invasive options, such as augmentation cystoplasty and urinary diversions. In this chart review, we find that SNM is an effective option prior to major surgical interventions. There is a high revision rate but overall, SNM is a minimally invasive procedure with a good safety profile and excellent long-term outcomes.
Figure 1
Figure 2
  1. Marcelissen T, Leong RK, de Bie RA, et al. Long-Term Results of Sacral Neuromodulation with the Tined Lead Procedure. J Urol 2010; 184: 1997-2000.
  2. Al-zahrani AA, Elzayat EA, Gajewski JB. Long-term outcome and surgical interventions after sacral neuromodulation implant for lower urinary tract symptoms: 14-year experience at 1 center. J Urol 2011; 185: 981-6.
  3. Van Voskuilen AC, Oerlemans DJAJ, Weil EHJ, et al. Long Term Results of Neuromodulation by Sacral Nerve Stimulation for Lower Urinary Tract Symptoms: A Retrospective Single Center Study. Eur Uro 2006; 49: 366-372.
<span class="text-strong">Funding</span> None <span class="text-strong">Clinical Trial</span> No <span class="text-strong">Subjects</span> Human <span class="text-strong">Ethics Committee</span> Nova Scotia Health Authority Research Ethics Board <span class="text-strong">Helsinki</span> Yes <span class="text-strong">Informed Consent</span> Yes