Sacral Neuromodulation in Non-Obstructive Urinary Retention and Painful Bladder Syndrome: an Update

Clinical Performance and Safety for the Rechargeable InterStim Micro System in Non-Obstructive Urinary Retention Subjects: 6-Month Results From the Global Post-Market ELITE Study

OBJECTIVE

To confirm the clinical performance and safety of the rechargeable InterStim Micro sacral neuromodulation system, we report the first results from the global ELITE study for the non-obstructive urinary retention cohort through 6 months of follow-up.

METHODS

Subjects were enrolled following successful therapy evaluation and neurostimulator implant. The primary objective was improvement in the number of clean intermittent self-catheterizations (CISC) per day at 3-months post-implant compared to baseline.

RESULTS

The change in the number of CISC per day from baseline was -3.5 (95% CI: -4.77, -2.26; n = 23) at the 3-month follow-up, which was statistically significant (P <.001) and signifies that the primary objective was met. This change was sustained at 6-month follow-up, with a change of -3.5 (95% CI: -4.73, -2.29; n = 24). There was a reduction in post-void residual of 244 mL (95% CI: -334.6, -154; n = 22) at 3 months and 264 mL (95% CI: -366.43, -161.56; n = 21) at 6 months vs baseline. On the Patient Global Impression of Improvement, 88% and 79% of subjects reported that their bladder condition was better at 3 and 6 months, respectively, compared to before they were treated with InterStim Micro. Device-, procedure-, or therapy-related AEs included implant site pain (11.1%; 3/27), medical device site discomfort (7.4%; 2/27), and pain in extremity (7.4%; 2/27).

CONCLUSION

This study reports on the non-obstructive urinary retention population of the global ELITE study, demonstrating the efficacy and safety of the InterStim Micro system through 6 months of follow-up.

Efficacy and Safety of Sacral Neuromodulation by Converting Constant Frequency Stimulation Into Variable Frequency Stimulation in Patients With Detrusor Overactivity and Impaired Contractility: A Single-Center Prospective Study

OBJECTIVES

In patients with detrusor overactivity with impaired contractility (DOIC), it is difficult to relieve abnormal lower urinary tract symptoms during both storage and voiding using sacral neuromodulation (SNM) with constant frequency stimulation (CFS). We sought to evaluate the efficacy and safety of SNM using variable frequency stimulation (VFS) in patients with DOIC by comparing it with outcomes of SNM with CFS.

MATERIALS AND METHODS

Between September 2020 and May 2021, we prospectively enrolled 20 patients with DOIC, confirmed on urodynamic examination, and administered SNM with VFS. The patients were followed up and required to maintain voiding diaries and record scale scores of overactive bladder symptoms, psychology and quality of life, uroflowmetry, ultrasonic postvoid residual urine, and adverse events at baseline and during the CFS and VFS phases.

RESULTS

The average testing phase was 26.3 ± 4.1 days. Compared with baseline values, overactive bladder symptom, psychologic health questionnaire, and quality of life scores, in addition to voiding frequency, urgency incontinence frequency, daily catheterization volume of voiding diary, and ultrasonic postvoid residual (PVR) decreased significantly during both the CFS and VFS phases (p < 0.05). The average voided volume, functional bladder capacity, and maximum urine flow rate significantly increased during the CFS and VFS phases (p < 0.05). In the VFS phase, voiding frequency, urgency incontinence frequency, daily catheterization volume of voiding diary, and ultrasonic PVR further decreased (p < 0.05), whereas functional bladder capacity, maximum urine flow rate, quality of life score, overactive bladder symptom score, and psychologic health questionnaire score further improved compared with results obtained in the CFS phase (p < 0.05). In the VFS phase, the success rate of further improvement of symptoms was 85.0%, and no new complications were noted.

CONCLUSIONS

SNM that converts CFS into VFS may be an effective treatment option for patients with DOIC, exhibiting no increase in adverse events.

Evaluation of the axonics modulation technologies sacral neuromodulation system for the treatment of urinary and fecal dysfunction

INTRODUCTION

Sacral neuromodulation (SNM) remains one of the few effective treatments for refractory bladder and bowel dysfunction. However, SNM is associated with frequent need for surgical intervention, in many cases because of a failed battery. A rechargeable SNM system, with a manufacturer-reported battery life of 15 years or more, has entered post-market clinical testing in Europe but has not yet been approved for clinical testing in the United States. Areas covered: We review existing neuromodulation technologies for the treatment of lower urinary tract and bowel dysfunction and explore the limitations of available technology. In addition, we discuss implantation technique and device specifications and programming of the rechargeable SNM system in detail. Lastly, we present existing evidence for the use of SNM in bladder and bowel dysfunction and evaluate the anticipated trajectory of neuromodulation technologies over the next five years. Expert commentary: A rechargeable system for SNM is a welcome technological advance. However surgical revision not related to battery changes is not uncommon. Therefore, while a rechargeable system would be expected to reduce costs, it will not eliminate the ongoing maintenance associated with neuromodulation. No matter the apparent benefits, all new technologies require extensive post-market monitoring to ensure safety and efficacy.