Urinary incontinence is common in women with an estimated prevalence of 500 Million world-wide, half of whom have stress urinary incontinence (SUI) .1  Pelvic Floor Muscle Training (PFMT) is the standard of care for nonsurgical treatment of stress urinary incontinence (SUI) with improvements reported in SUI including volume via pad weight, voiding frequency and Quality of Life (QoL).  Because of its limited efficacy, enhancements to PFMT are needed, especially in women who are not interested in or are not candidates for surgery.  Muscles are known to respond to mechanical stresses and are highly sensitive to vibration.2,3   The aim of this study is to determine whether mechanotherapy (MT) applied to the pelvic floor muscles (PFM) in conjunction with PFMT improves continence compared to PFMT without MT in women with SUI.  This abstract includes the first presentation of results from an interim analysis of an ongoing clinical trial.

This is a prospective, randomized, controlled trial. The novel device used for this study (Flyte™, Pelvital, Inc., Minneapolis, MN, USA) is a vaginal device that provides MT in two ways: 1) a carefully engineered probe that creates a preload on the PFM prior to muscle contraction.  This pre-stress is expected to augment the effect of PFMT; 2) mechanical oscillations in conjunction with biofeedback which presumably provides incremental benefit.  Previous animal and human research have elucidated the effect of mechanical stimulation on muscle strength function. Subjects with SUI were randomized to a Treatment Arm (MT with biofeedback including mechanical oscillations + PFMT) versus a Control Arm (MT without oscillations + PFMT). Subjects were asked to perform therapy daily for 5 minutes. Endpoints included 24hr Pad Weight (primary endpoint) and quality of life (QoL) assessed with the validated ICIQ-UI-SF, in addition to subjective reporting of voiding frequency. Endpoints were assessed at 6 and 12 weeks. The primary endpoint was determined at 6 weeks, at which time Control subjects were crossed over to the intervention arm.

We present interim analysis of pooled data from the current study, as study arm assignment has not been unblinded.  Subjects demonstrated a median 59% relative improvement in PW at 6 weeks and 68% at 12 weeks. Compared to Baseline, there were statistically significant decreases in mean 24hr PW and median 24hr PW.  Subjective voiding frequency improved significantly at both 6 and 12-weeks. Table 1 summarizes these findings.  Furthermore, QoL measured by the Total ICIQ-UI-SF score improved (p=0.07).

PW data was further stratified by severity level.  Statistically significant improvements were noted in Mild and Moderate severity subjects at both 6 and 12-weeks, and near significance in Severe subjects (cohort sample size was small and data variance large) (Figure 1).

Study subjects demonstrated significant reductions in 24hr pad weight and voiding frequency with Flyte™ therapy. Approximately 80% of the subjects of the subjects responded to the therapy with 60% of subjects having decreased PW >50% at 6-weeks which improved further to 73% at 12-weeks.  Clinical benefits were generally sustained after the study ended despite no further therapy. It was noted that some subjects responded exceptionally well with almost complete eradication of urine leakage while approximately 20% of women were non-responders. These observations occurred regardless of incontinence severity level at baseline. The lack of response in some subjects suggests a condition requiring further clinical evaluation and possibly more aggressive treatment.  Possible mechanisms responsible for lack of response need to be explored in future research studies.

Flyte™ used as an adjunct to PFMT, significantly improved stress urinary incontinence as measured by PW, QoL and voiding frequency in women with SUI across all levels of severity.  Further improvement was observed between 6-weeks and 12-weeks that included the crossed-over subjects. Flyte™ therapy provided an effective, non-invasive therapeutic option in women with SUI.

Urinary incontinence treatment devices market: snapshot. Transparency Market Research website. https://www.transparencymarketresearch.com/urinary-incontinence-treatment-devices-market.html. Accessed August 23, 2018.
Salanova M, Gambara G, Moriggi M, et al. Vibration mechanosignals superimposed to resistive exercise result in baseline skeletal muscle transcriptome profiles following chronic disuse in bed rest. Sci Rep. 2015;5:17027.
Blottner D, Salanova M, Püttmann B, et al. Human skeletal muscle structure and function preserved by vibration muscle exercise following 55 days of bed rest. Eur J Appl Physiol. 2006;97:261-271.