Circumferential urinary sphincter surface electromyography: A novel diagnostic method for intrinsic sphincter...

Area of Science:

• Urology
• Gynecology
• Neuroscience

Background:

• Stress urinary incontinence (SUI) diagnosis, particularly intrinsic sphincter deficiency (ISD), lacks established methods.
• Assessing urethral sphincter muscular integrity is crucial for understanding SUI/ISD pathophysiology.

Purpose of the Study:

• To evaluate the utility of minimally invasive circumferential sphincter surface electromyography (CSS-EMG) for diagnosing ISD in SUI patients.
• To explore CSS-EMG as a tool for assessing urethral sphincter muscular integrity.

Main Methods:

• CSS-EMG and urodynamic studies were conducted in 44 women with SUI.
• Urethral pressure profile (UPP) was measured, and ISD was defined by maximal urethral closure pressure (MUCP) <40 cm/H2O or SUI without hypermobility.
• Average rectified value (ARV) of motor unit action potential (MUAP) was estimated as an indicator of rhabdosphincter strength.

Main Results:

• CSS-EMG's ARV in the 12 o'clock quadrant during maximal contraction significantly predicted ISD (OR 0.36, 95% CI 0.67-0.92).
• A higher 12 o'clock ARV value correlated with a decreased likelihood of ISD.
• The ROC curve analysis showed CSS-EMG's ARV at the 12 o'clock position was a significant predictor of ISD (area 0.794, P=0.02).

Conclusions:

• Myogenic changes contributing to ISD can be effectively assessed using CSS-EMG.
• This novel CSS-EMG approach offers a new method for evaluating female urethral sphincter function.
• The findings may improve the understanding, diagnosis, and treatment of SUI and ISD.