Do Ultrasound Measures of Bladder Neck Location and Movement During Pelvic Floor Contraction or Straining Relate to Bladder Neck Support During Voiding?

PURPOSE: Poor support of the bladder neck is common in voiding dysfunction but remains difficult to assess. Transperineal ultrasound imaging during voiding provides reliable measures but is not yet implemented in practice. This study aimed to investigate whether conventional measures of bladder neck position during straining and pelvic floor muscle contraction correlate with support during voiding, potentially serving as surrogate measures. A secondary objective was to compare the measures between nulliparous and parous participants.

MATERIALS AND METHODS: Thirty asymptomatic women underwent transperineal ultrasound to measure bladder neck position during voiding, maximal straining, and maximal pelvic floor muscle contraction. Measurements included the pubourethral angle and the distance between the symphysis and bladder neck, recorded at rest, start and end of voiding, and during maximal strain and pelvic floor muscle contraction. Correlations were calculated between the end position and changes in bladder neck position during voiding and during strain or contraction.

RESULTS AND CONCLUSIONS: No significant correlations were found between the changes during voiding and the other tasks. Moderate to strong correlation were observed between bladder neck position at the end of voiding and the other tasks. There was no significant differences between nulliparous and parous participants. The findings suggest that the bladder neck displacement during voiding cannot be inferred from the movements during strain or pelvic floor muscle contraction. Although there is correlation between position at the end of each task, this does not reflect the dynamic change in voiding, which is likely crucial for clinical assessment and understanding of voiding dysfunction.