Objective: The purpose of this study was to assess the effect of detrusor overactivity and bladder filling on urethral function with the use of urethral profilometry.
Study design: Women with symptoms of urinary incontinence were recruited from our urodynamic clinic. All of the women underwent videocystourethrography and urethral pressure profilometry with the bladder empty and then full. The maximum urethral closure pressure, mean urethral pressure, functional urethral length, and pressure transmission ratios for each quartile were analyzed.
Results: Thirty-five women were recruited: 17 women had urodynamic stress incontinence, and 18 women had detrusor overactivity. In women with urodynamic stress incontinence, there was a significant increase in maximum urethral closure pressure and pressure transmission ratios over all quartiles when the bladder was full compared with empty. In women with detrusor overactivity, there was a significant decrease in functional urethral length and pressure transmission ratios in the second and third quartile of the urethral pressure profiles when the bladder was full compared with empty.
Conclusion: Decreases in functional urethral length and pressure transmission ratios with bladder filling in those women with detrusor overactivity are at variance with the normal physiologic response to bladder filling, which suggests that urethral function is affected by the presence of abnormal detrusor activity and that the valid assessment of urethral function may not be possible if the detrusor overactivity is not treated.