Hypothesis / aims of study
In according to the Petros and Ulmsten’s integral theory the stress urinary incontinence (SUI) is caused by either a combination of intrinsic sphincter deficiency (ISD) and urethral hypermobility. However, it caused by ISD alone is rare whereas urethral hypermobility occurs frequently without SUI. The aim of this study was to correlate the ISD assessed by urodynamic test with the urethral hypermobility evaluated by trans labial ultrasound in women with SUI.
Study design, materials and methods
This was a prospective study on women with SUI. The local ethics committee approved the study and all patients signed an informed consent document.We included women with pure SUI and mixed urinary incontinence with predominant stress form. We excluded women with pelvic organ prolapse or with a history of anti incontinence surgery.They were evaluated by translabial ultrasound and urodynamic test. Ultrasound was performed by a 3.5-5 MHz curved array probe with the patient at rest and during a maximum Valsalva manoeuvre in the dorsal lithotomy position.The symphysis pubis, was used as a landmark to evaluate bladder neck position and mobility.To assess bladder neck mobility, we measured the distance between the bladder neck and the longitudinal axis of the symphysis. We recorded distances above and below the longitudinal axis of the symphysis as negative and positive respectively. The urodynamic test was done according to the ICS good pratice protocol. The VLPP ≤60 cm H2O was used as cut off for the diagnosis of ISD.We divided the patients into three groups: 1) VLPP≤60 cm H2O, 2) 60<VLPP≤90 cm H2O, 3) VLPP>90 cm H2O. All continuous variables were normally distributed. Associations between VLPP data and each of the continuous explanatory variables were summarized as Pearson’s correlation coefficients.We considered p < 0.05 to be statistically significant.
Interpretation of results
The lack of correlation between urodynamic parameters and ultrasound-assessed hypermobility could be explained by the pathophysiology of stress incontinence. Stress incontinence is caused by ISD which can be associated with urethral hypermobility, but not necessarily