Development of primary design guidelines for supportive underwear to elevate the bladder neck in women based on finite element analysis of the pelvis.

The use of supportive underwear has been applied for preventing stress urinary incontinence (SUI) which is caused by descent of the bladder neck due to weakness in the pelvic floor muscles, because it is known that SUI can be improved by elevating the descended bladder neck. However, appropriate approaches to the underwear design are still being explored. In order to establish an appropriate first-order design strategy for supportive underwear, clarifying the relationship between the pressure from the underwear and the amount of elevation of the bladder neck is necessary. We constructed a finite element model of the pelvis based on magnetic resonance images of a subject in an upright position, experimentally explored Young's modulus of the soft tissue and analyzed the amount of elevation of the bladder neck when changing the combination of applied pressures from the underwear. The position of the bladder neck relatively elevated when the pressure in the region from the abdomen to the pubis decreased and when the pressure in the region from the perineum to the coccyx increased, suggesting an appropriate design for the supportive underwear.

Effects of wearing supportive underwear versus pelvic floor muscle training or no treatment in women with symptoms of stress urinary incontinence: an assessor-blinded randomized control trial.

INTRODUCTION AND HYPOTHESIS: In our previous single-arm pilot study, we reported that ready-made supportive underwear (shaper) was effective in elevating the bladder neck and reducing urinary incontinence (UI) symptoms. The aim of this study was to determine the effects of wearing a shaper compared with pelvic floor muscle training (PFMT) at home using a training compact disc with music, or no treatment, in an assessor-blinded randomized control trial, on reducing UI symptoms. METHODS: Participants aged 30-59 years with symptoms of stress urinary incontinence were randomly assigned to three groups: the shaper group, PFMT group, and no treatment group. The UI episodes/week and the Japanese version of the International Consultation on Incontinence Questionnaire Short-Form were compared between the baseline and the 6th or 12th week of the intervention period. RESULTS: Eighty-nine women who completed the 12-week intervention period were analyzed. After the 12-week intervention period, the improvement rate in UI symptoms (ratio of the case number in which the UI episodes/week decreased at least 50% from the baseline) was 73.3% (22/30 women) in the shaper group, 74.2% (23/31 women) in the PFMT group, and 25.0% (7/28 women) in the no treatment group. The improvement rate in UI symptoms in the shaper and PFMT groups was significantly higher than that in the no treatment group (both P < 0.001). CONCLUSIONS: Wearing supportive underwear (shaper) was almost as effective as PFMT at home in reducing UI symptoms.

Prevalence and Risk Factors of Urinary Incontinence and Overactive Bladder in Japanese Women.

OBJECTIVES: The prevalence of storage symptoms, including stress urinary incontinence (SUI) and overactive bladder (OAB), is high in women worldwide. In Japan, there have been few large-scale epidemiological surveys of lower urinary tract symptoms (LUTS), and the risk factors for these symptoms are unclear. The aim of this study was to explore the prevalence and risk factors of storage symptoms in Japanese women. METHODS: A cross-sectional Internet survey was conducted in Japan. Five thousand women aged 20-79 years were selected to answer demographic questionnaires, Japanese version of International Consultation on Incontinence Questionnaire-Short Form, and the Overactive Bladder Symptom Score (OABSS) pertaining to their symptoms in the previous month. Descriptive statistics were used to evaluate the prevalence of storage symptoms. Logistic regression analysis was performed to determine risk factors for SUI and OAB. RESULTS: The answers from 4804 women (average age, 40.4 years) were analyzed. The prevalence of SUI was 16.7% (SUI, 13.0%; mixed urinary incontinence, 3.7%). The prevalence of OAB diagnosed on OABSS was 8.1%. The prevalence of SUI and OAB symptoms increased with age, and 68.0% of women had one or more storage symptoms. Age ≥40 years, body mass index ≥25 kg/m2 , and constipation were common risk factors for SUI and OAB. Childbirth was an additional risk factor for SUI. CONCLUSIONS: The prevalence of storage symptoms in Japanese women was high, and risk factors associated with these symptoms were similar to those reported in studies in other countries.

Single-Arm Pilot Study to Determine the Effectiveness of the Support Power of Underwear in Elevating the Bladder Neck and Reducing Symptoms of Stress Urinary Incontinence in Women.

OBJECTIVES: To verify the effectiveness of support power of underwear (the shaper) to elevate bladder neck and to reduce symptoms of stress urinary incontinence (SUI). METHODS: This was a single-arm pilot study conducted in Japan by using the shaper (SLIM-up-Pants with Style Science, Wacoal Corporation, Kyoto, Japan). The bladder neck position in a sitting posture was recorded using an open-configuration magnetic resonance system and then compared between parous women with SUI, without and with the shaper. Women wore the shaper during the daytime for 12 weeks, followed by one week during which they did not wear the shaper. The symptoms of urinary incontinence (UI) were assessed based on the 1-h pad test, the Japanese version of the International Consultation Incontinence Questionnaire-Short Form, and the incontinence diary. RESULTS: Forty-five Japanese women with SUI, aged between 27 and 65 years, were included. When the shaper was worn, the bladder neck was found to be significantly elevated by 11.5 mm (median; P < 0.05/6 = 0.008). After 12 weeks, all symptoms of UI decreased significantly (P < 0.05/3 = 0.016), and the bladder neck was further elevated by 4.7 mm (median; P < 0.001) even when not wearing the shaper. In addition, after one week of not wearing the shaper, the bladder neck position remained elevated and symptoms of UI did not recur immediately. CONCLUSION: The shaper was considered to be effective in elevating the bladder neck and reducing symptoms of UI.