Wearable neuromodulation device shows promise for overactive bladder

July 30, 2020

Feasibility study results indicate the nonimplanted, intravaginal device is safe and comfortable.

A nonimplanted, intravaginal neuromodulation device (FemPulse) for treating overactive bladder (OAB) symptoms demonstrated favorable results in a feasibility study assessing wearability, safety, and clinical utility, reported Suzette E. Sutherland, MD, MS, FPMRS, at the 2020 American Urological Association Virtual Experience.1

“This device aims to provide a simple, convenient, and affordable form of continuous neuromodulation to ameliorate bothersome symptoms of OAB. The collective findings of the feasibility study justify its further investigation,” said Sutherland, the primary study investigator and director of Female Urology at the University of Washington School of Medicine in Seattle.

Sutherland’s coinvestigators were Steven W. Siegel, MD, FPMRS, Minnesota Urology in St. Paul, Minnesota, and Michael J. Kennelly, MD, FACS, FPMRS, McKay Urology, in Charlotte, North Carolina.

The FemPulse device is a pessary-like ring that is placed against the cervix for delivering electrical stimulation to the inferior hypogastric plexus, known as the pelvic plexus. The final iteration of the device will be a self-contained unit. However, the device investigated in this feasibility study was an initial prototype that was connected via wires exiting the vagina to an FDA-cleared transcutaneous electrical nerve stimulator (TENS).

The multicenter feasibility study randomized 21 women 2:1 to treatment versus sham groups. The treatment subjects received a conductive connector and stimulation at around 70% of the subject’s sensation threshold. The system used for sham patients had a nonconductive connector, but all other aspects of the set-up were identical. At the initial study visit, patients completed pretherapy (or sham) quality-of-life (QOL) questionnaires; underwent a vaginal exam; were assessed for device fit, comfort, and self-maneuverability; and underwent preliminary stimulation testing and mapping, after which the device was removed. The participants then completed a 3-day bladder diary and returned the following week for randomization, device placement, and configuration. They completed another 3-day bladder diary and then returned for a final visit on the following day to undergo device removal, a final vaginal examination, and complete posttherapy (or sham) QOL questionnaires.

Device reported to be comfortable

In an intent-to-treat (ITT) cohort that included all 19 women who completed the study, the device was fit easily and was reported to be comfortable. In addition, it exhibited good self-maneuverability, as 86% of subjects could place and orient the device and 79% were able to remove it without assistance.

“A few patients had difficulty reaching the device to remove it either because of the length of their vaginal canal or their body habitus. A future iteration of the device will include a feature for assisting with self-placement and removal,” Sutherland said.

Safety of the device was demonstrated, as there were no clinically important direct or reflexive effects on heart rate, rhythm, or blood pressure during stimulation, nor any untoward issues in the vagina due to the device. One woman reported mild lower abdominal ache or cramping that resolved when the device was removed. She also noted scant pink-tinged blood on the device following final removal.

“This patient had no sense of discomfort or irritation on [the] vaginal exam that was attributable to the device. It was concluded that the blood was related to postmenopausal atrophic tissues,” Sutherland said.

Clinical utility was evaluated by analyses of changes in voids per 24 hours, urgent voids per 24 hours, changes in urinary urge, and incontinence-related QOL questions from 3 validated questionnaires. In the ITT cohort, similar improvements in these parameters were seen in both the treatment and control groups. However, signals of treatment benefit were observed in an efficacy-analysis (EA) subgroup comprised of 11 women (7 treatment subjects, 4 controls).

“The EA subgroup excluded 6 treatment subjects and 2 controls who reported feeling the stimulation, and who were therefore thought to be biased,” said Sutherland.

“It was in this EA subgroup that a trend toward OAB improvement in the stimulation group compared to controls was seen, which in turn provides the justification to pursue larger-scale investigations into the efficacy of the FemPulse device for the treatment of OAB.

Disclosure: FemPulse provided funding for the study. Dr Sutherland is a study investigator and consultant for FemPulse and other companies that market or are developing treatments for OAB.

Reference

1. Sutherland SE, Kennelly MJ, Siegel SW. Evaluation of a non-implanted, transvaginal, electrical stimulation continence device for overactive bladder: EVANESCE-OAB. Paper presented at: 2020 American Urological Association Virtual Experience; June 27-28, 2020. Abstract PD27-09