Elsevier

Urology

Volume 94, August 2016, Pages 57-63
Urology

Female Urology, Urodynamics, Incontinence, and Pelvic Floor Reconstructive Surgery
Three-year Follow-up Results of a Prospective, Multicenter Study in Overactive Bladder Subjects Treated With Sacral Neuromodulation

https://doi.org/10.1016/j.urology.2016.04.024Get rights and content

Objective

To evaluate the therapeutic success rate, and changes in quality of life (QOL) and safety in subjects using sacral neuromodulation (InterStim System) at 36 months. Subjects with bothersome symptoms of overactive bladder (OAB) including urinary urge incontinence (UI) and/or urgency frequency (UF), who had failed at least 1 anticholinergic medication, and had at least 1 untried medication were included.

Methods

Subjects with successful test stimulation received an InterStim implant. Therapeutic success and quality of life through 36 months was evaluated in implanted subjects with data at baseline and follow-up. Safety was evaluated using reported adverse events.

Results

A total of 340 subjects received test stimulation resulting in 272 implanted subjects. Demographics include 91% female, mean age of 57 years, and baseline symptom severity of 3.1 ± 2.7 leaks/day (UI) and 12.6 ± 4.5 voids/day (UF). The analysis showed an OAB therapeutic success rate of 83% (95% confidence interval: 78%-88%). UI subjects had a mean reduction from baseline of 2.3 ± 2.3 leaks/day whereas UF subjects had a mean reduction of 5.3 ± 4.0 voids/day (both P < .0001). Statistically significant improvements were observed in all measures of the International Consultation on Incontinence Modular Questionnaire-OABqol (all P < .0001). Eighty percent of subjects reported improvements in their urinary symptom interference. Device-related adverse events occurred in 47% (127/272) of subjects post-implant; 91% were resolved at the time of this analysis.

Conclusion

The 36-month follow-up data from the multicenter study demonstrate sustained safety, effectiveness, and improved QOL in subjects implanted with InterStim, without requiring failure of all medications.

Section snippets

Methods

Enrollment criteria and design were published previously.2, 3 Subjects had a primary diagnosis of OAB as demonstrated on a 3-day voiding diary demonstrating ≥ 8 voids per day (urgency frequency, UF) and/or ≥ 2 involuntary leaking episodes in 72 hours (urinary incontinence, UI).

Institutional Review Boards approved the protocol and informed consent forms were signed prior to participation in study activities. All subjects underwent a staged implant procedure with the InterStim System

Results

Overall, 340 subjects received test stimulation and 272 subjects were implanted with the InterStim System. Baseline demographics are listed in Supplementary Table S1. Subjects had tried a median of 2 OAB medications prior to full system implant. On average, UI subjects had 3.1 ± 2.7 leaks/day; UF subjects had 12.6 ± 4.5 voids/day at baseline. There were 217 subjects followed up until 36 months, with 193 subjects with a voiding diary at baseline and at 36 months. Seventeen subjects who

Discussion

OAB is a chronic condition that must be managed successfully over time to provide meaningful benefit. This prospective study demonstrates sustained safety and efficacy of SNM in OAB subjects after 36 months of treatment and will continue to follow study subjects up to 60 months. There is minimal drop-off in therapeutic success when compared to results at 1 year.3 Improvements in QOL, sexual function in female subjects, and pelvic pain measures were sustained. The rate of device-related AE (47%)

Conclusion

The InSite trial is an ongoing, large, prospective multicenter study designed to evaluate the long-term safety and efficacy of SNM for subjects with refractory symptoms of OAB. This paper reports the results after 3 years of therapy, demonstrating that implanted subjects maintained improvements in OAB symptoms and QOL. Whereas the rate of AEs and the need for reoperation are acknowledged concerns related to this therapy, they are reduced compared to prior studies.

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Financial Disclosure: Steven Siegel is a patent holder at MDT, BSI, and QIG; and has received consulting fees from MDT, Allergan, and NuVectra, and speaking fee/proctor from MDT and QIG. He has also contracted research for MDT and IPSEN. Karen Noblett received consulting fees from MDT, Axonics, and speaking fee/proctor from MDT and BSI. She also contracted research for MDT. Suzette E. Sutherland is a study investigator for Medtronic and Allergan, and a paid consultant for Medtronic, Allergan, and Axonics. Jason Bennett is a study investigator and consultant for Medtronic, and a consultant for Intuitive. Fangyu Kan and Elizabeth Thiery are employees of Medtronic. The remaining authors declare that they have no relevant financial interests.

Funding Support: Medtronic, Inc., sponsored this study in full.

ClinicalTrials.gov identifier: InSite for Overactive Bladder, NCT00547378.

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