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A minimally invasive, coin-sized implantable device was effective in treating overactive bladder (OAB) syndrome, researchers found.

In a prospective, single-arm, open-label study funded by the device's manufacturer, the novel, leadless tibial nerve stimulator achieved at least a 50% reduction in urgency urinary incontinence in two-thirds of the patients, reported Alexandra Rogers, MD, of Sansum Clinic in Santa Barbara, California, and colleagues.

The device -- called eCoin (electroceutical coin) -- "offers a novel OAB therapy with minimal compliance issues due to automatic therapy delivery and a well-tolerated, reproducible implantation procedure, all precipitating the potential for high adoption once available," the investigators explained in the study online in the .

They noted that OAB affects up to 33 million people in the U.S. The study targeted urgency urinary incontinence, which represents about one-third of cases of OAB and significantly impacts quality of life. A "staggering" number of patients lack treatment options, the researchers said.

Second-line medications are often ineffective with "intolerable side effects," while third-line options, such as percutaneous tibial nerve stimulation, onabotulinumtoxinA, and sacral neuromodulation surgery, are invasive and/or need maintenance with continuing office visits.

In contrast, the eCoin device is implanted subcutaneously in the lower leg and delivers automatic 30-minute treatments without the need for patient manipulation, Rogers and co-authors explained.

"This is going to be groundbreaking in terms of additional therapies that we can give to the overactive bladder patient population," commented Casey Kowalik, MD, of the University of Kansas Health System in Kansas City, who was not involved with the study.

"I'm very encouraged by these results in terms of the number of patients who had improvements -- even long term. It seems like it will be a nice, durable treatment that will be minimally invasive, which is particularly good for those patients who aren't great candidates for surgery," she told 乌鸦传媒. "It's challenging, but rewarding, to treat these patients, because if you find the right treatment for them you significantly improve their quality of life."

Kowalik noted that she often treats patients who because of age or frailty may not be able to tolerate medications; are not good candidates for sacral neuromodulation surgery; or are unable to drive and thus can't make the maintenance visits necessary with percutaneous tibial nerve stimulation.

"This may be a great option for them, where it's an implanted device under local anesthesia, they don't have to make the trips to the office and they still get significant improvement in their urinary symptoms," she said.

The study, conducted across 15 U.S. sites, included 137 patients with refractory urgency urinary incontinence.

The device was implanted in the medial lower leg above the fascia, and activated 4 weeks later. eCoin delivered automated stimulation sessions of 30-minute durations every 3 days for 18 weeks, and every 4 days after that. Patients were followed for 48 weeks, with follow-up visits at 4, 8, 12, 24, 36, and 48 weeks.

The primary outcome was the percentage of subjects who achieved at least a 50% reduction from baseline in episodes of urgency urinary incontinence after the 48 weeks of therapy.

Of the 137 patients enrolled in the study, 132 (98% of whom were women) were included in the intent-to-treat analysis.

The median device implantation time using only local anesthesia was 19.8 minutes. About two-thirds of participants (68%) achieved at least 50% reduction in episodes of urgency urinary incontinence 48 weeks after the device was activated, and the percentages were comparable at 24 and 36 weeks (69% and 70%, respectively).

The team also performed sensitivity analyses to evaluate the effect of the COVID-19 pandemic on outcomes by comparing data before and during the pandemic, as well as whether the data were collected in person or remotely:

• The pre-pandemic and in-person responder rates were 75% and 74%, respectively

• The responder rate during the pandemic was 60%

• The responder rate of remote visits was 57%

Throughout the 52 weeks of implantation, 19% of patients experienced device- or procedure-related adverse events (AEs), including 16% who reported device-related AEs. There was an infection rate with resolution of 2.25%, which the authors noted was similar to existing implanted neuromodulation data. One serious AE was reported -- an infection related to the implantation procedure that resulted in the device being removed.

Rogers and co-authors acknowledged that longer-term follow-up is needed beyond the study's 12-month medium-term efficacy data. Another limitation was that by their nature, neuromodulation studies in general are not usually blinded, so it was not possible to have a control group with a similar safety profile.

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