Low-Intensity Extracorporeal Shock Wave Therapy Restores Passive Urethral Closure Mechanism in Vaginal Distension Rat...

Area of Science:

• Urology
• Regenerative Medicine
• Biomedical Engineering

Background:

• Stress urinary incontinence (SUI) is a prevalent condition affecting women's quality of life.
• Low-intensity extracorporeal shock wave therapy (LiESWT) is an emerging noninvasive treatment for SUI.
• The mechanisms underlying LiESWT's efficacy, particularly pelvic floor tissue remodeling and endoplasmic reticulum stress, require elucidation.

Purpose of the Study:

• To evaluate the efficacy of LiESWT in restoring urethral function in a rat model of SUI induced by vaginal distension (VD).
• To investigate the potential mechanisms involving pelvic floor tissue remodeling and the endoplasmic reticulum stress pathway.

Main Methods:

• Eighty-one female Sprague-Dawley rats were utilized for functional and tissue analyses.
• Urethral pressure responses were assessed by inducing sneezing.
• Leak point pressure (LPP) was measured, with and without nerve transections, alongside histological and molecular expression analyses for tissue remodeling and pathway assessment.

Main Results:

• Vaginal distension (VD) rats exhibited significantly lower baseline urethral pressure and LPP compared to normal rats.
• LiESWT successfully restored urethral pressure and LPP in VD rats, with improvements persisting even after nerve transections.
• LiESWT showed a trend towards reducing vaginal smooth muscle fibrosis, though collagen and elastin expression remained elevated; no sustained endoplasmic reticulum stress pathway activation was observed.

Conclusions:

• LiESWT effectively enhanced urethral function in a VD-induced SUI rat model, likely through pelvic floor tissue remodeling.
• The therapy appears to restore passive urethral closure mechanisms.
• The lack of sustained endoplasmic reticulum stress pathway activation suggests LiESWT is a safe therapeutic option for SUI.