Sacral Neuromodulation in Patients with Underactive Bladder: The Outcomes of a Multicenter Case Series

Hajebrahimi S1, Onur R2, Tayebi S3, Salehi-Pourmehr H1, Jahantabi E3

Research Type


Abstract Category

Continence Care Products / Devices / Technologies

Abstract 142
On Demand Continence Care Products / Devices / Technologies
Scientific Open Discussion Session 15
Underactive Bladder Neuromodulation Voiding Dysfunction
1. Research center for Evidence Based-Medicine, Iranian EBM Center: A Joanna Briggs Institute Center of Excellence, Tabriz University of Medical Sciences, Tabriz, Iran, 2. Department of Urology, Marmara University, Istanbul, Turkey., 3. Urology department, faculty of medicine, Tabriz University of Medical Sciences, Tabriz, Iran.

Sakineh Hajebrahimi



Hypothesis / aims of study
Detrusor underactivity (DU) or underactive bladder (UAB) is a common urological condition that has been receiving specific interest recently. We report the long-term outcomes of sacral neuromodulation (SNM) in detrusor underactivity (DU) and chronic non-obstructive urinary retention.
Study design, materials and methods
This multicentric retrospective case series study was conducted between March 2017- October 2020 in two referral functional urology centers in Iran and Turkey. Local ethics permission was gained. Patients who suffered from DU or chronic non-obstructive urinary retention, refractory to conservative therapies (life style modifications, pharmacological treatment) were enrolled in this investigation. A total of forty-six cases underwent SNM between March 2017 and October 2020. To assess patients’ response to treatment (stage I), temporary percutaneous stimulation was used prior to permanent implantation. Patients were observed for two weeks following surgery, and if treatment response was 50 percent or more, the implantable pulse was placed in stage II of the study.
The mean age of patients was 37.46 ± 13.58 years, with a male to female ratio of 1:1. The etiology of disease in 32 patients (69.6%) was idiopathic, while the others had neurogenic conditions.   Thirty-two (69.6 %) patients responded to stage I, of which 75%  either experienced a reduction in CIC frequency, PVR, or void spontaneously , or were fully treated by the end of stage II. Fourteen patients (7 idiopathic, 7 neurologic) showed no response to stage I . The mean follow-up interval was 18.16 (2-46) months. Voided volume improved significantly, from a median of 62.50 (range 0.0-600.0) to 226.50 (range 0.0-550.0) (p < 0.001). The median PVR was reduced from 400 (range 150.0 to 1000.0) to 170 ml (range 0 to 800) (p < 0.001), and the median Qmax from 2 (range 0 to 13) to 12 (range 0 to 21) (p < 0.001). Idiopathic DU cases showed statistically significant improvement in their urodynamic study results for voided volume (P=0.004), Qmax (P=0.023), and PVR (P=0.040) as compared to neurogenic patients.In addition, the GRA(Global Response Rate) of idiopathic cases showed better success than neurogenic patients (P= 0.008). Although no complications occurred during stage I,  two device revisions (due to pain at implantation site), three cases of lead migration, one implantation site infection, and One case of pain and spasm in the lower extremity without lead migration were observed during the follow-up period of stage II.
Interpretation of results
This retrospective multicenter study has advanced the overall knowledge of SNM therapy for underactive bladder. The results showed that SNM effectively and safely provides promising results for refractory cases of DU, in whom the first and second line treatment have failed.
Concluding message
SNM effectively and safely provides promising results for refractory cases of DU, in whom the first and second line treatment have failed.
Funding None. Clinical Trial No Subjects Human Ethics Committee Tabriz University of Medical Sciences Helsinki Yes Informed Consent Yes
15/02/2024 02:05:22