Overactive bladder (OAB) is a syndrome consisting of any one of four key symptoms: urinary urgency, urge incontinence, urinary frequency, and nocturia. The physiologic basis of these symptoms is detrusor overactivity (DO), defined as spontaneous or provoked involuntary detrusor contractions. OAB can seriously impair the quality of life scale (QoL) of the sufferer and is a major financial burden on healthcare. Extracorporeal low intensity shock wave therapy (LiESWT) has been used clinically to improve tendonitis, ischemic cardiovascular disorders, skin wound healing and erectile dysfunction. Previous reports showed the shock intensity in rat model ranging from 0.10-0.13 mJ/mm2 and the shock number ranging from 200 to 300 impulses were the optimal parameters to increase cell viability and angiogenetic factors, and decrease inflammation mediators. We hypothesize that clinical application of LiESWT on overactivity bladder (OAB) patients could attenuate inflammatory responses, increase angiogenesis, improve bladder overactivity and promote the quality of life (QoL). Our aim is to evaluate the effects of LiESWT on OAB syndrome, including urinary frequency, urgency, urge incontinence, and nocturia.

Our instrumentation is extracorporeal shock wave therapy system, the STORZ MEDICAL EvoTronTM (DUOLITH SD1, GA) shock wave (focused). The LiESWT was applied once weekly for 8 weeks.The LiESWT will be applied with intensity (0.25 mJ/mm2), the number of shocks (3000 pulses), and frequency of 3 pulses /second as modified from previous reports. The control group received a LiESWT of the simulation treatment, but the treatment of LiESWT machine does not operate (sham operation). Eligible subjects include female outpatients aged 20~75 years who have been diagnosed with OAB symptoms for at least 3 months. Subjects were excluded if they had significant coagulopathy, perineal anatomical abnormalities, neurological abnormalities, unstable psychiatric disorders, uncorrected hormone abnormalities, and clinically significant medical diseases. The participants will complete the validated questionnaire of pre-treatment versus post-treatment of LiESWT to assess the change in overactive bladder questionnaire short form [Overactive Bladder Symptom Scores (OABSS), International Consultation on Incontinence Questionnaire - Short Form (ICIQ-SF); Urogenital Distress Inventory (UDI-6)-Short Form and incontinence impact questionnaire-7 (IIQ-7) score, uroflowmetry and measurement of post void residual urine volume, and three-day voiding diary.

A total of 60 patients with a mean age 55.90±9.19 years were enrolled. Changes in clinical symptoms at W8 of LiESWT showed the mean values of functional bladder capacity increased from 338.06±28.93 to 356.80±24.43 (ml), while the urgency decreased from 4.45±0.73 to 2.78±0.59 (times/ 24hrs). The mean values of nocturia also decreased from 1.72±0.17 to 1.18±0.24 (times). Moreover, OABSS, ICIQ-SF, UDI-6 and IIQ-7 scores also showed a significant improvement compared with the baseline level. No adverse effects, such as hematuria or skin ecchymosis noted during the whole treatment course.

Generally, LiESWT was used to improve tissue regeneration in  ischemic cardiovascular disorders, skin wound healing, and chronic injuries of soft tissues and erectile dysfunction. LiESWT has also been shown to increase VEGF expression in ischemic tissues in vivo and to promote angiogenesis and functional recovery . In the present stufy, LiESWT improved bladder overactivity, decrease frequency and urgency. The proposed therapeutic mechanisms of action for Li-ESWT include neovascularization, tissue regeneration, and reduction of inflammation. These effects are thought to be mediated by enhanced expression of vascular endothelial growth factor, endothelial nitric oxide synthase, and proliferating cell nuclear antigen. The dominant effect of low-intensity shock waves is
thought to be mechanotransduction. Rather than inducing damage in the target, Li-ESWT may induce tissue healing and angiogenesis.

LiESWT ameliorated bladder hyperactivity, improved OAB syndrome, including urinary urgency, urinary frequency, and nocturia, and promotes the quality of life. The clinically used drug treatment of OAB includes anti-muscarinic agents or/and ß3 agonist medication. However, their use is frequently associated with adverse effects, especially anti-cholinergic effects such as dry mouth, constipation and blurred vision.  Using LiESWT, a non-medical and noninvasive therapy without bothersome adverse effect colud serve as an  important alternative treatment for OAB.

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