Urethral retro-resistance pressure and urodynamic diagnoses in women with lower urinary tract symptoms.

OBJECTIVE: This study determines whether the retrograde urethral retro-resistance pressure (URP) measurement discriminates between urodynamic diagnoses in a group of women. DESIGN: A prospective observational study. SETTING: Urogynaecology units of three tertiary referral teaching hospitals. POPULATION: Women with lower urinary tract symptoms. METHODS: Consecutive women attending the urodynamic clinics of three tertiary referral teaching hospitals were studied using a validated urinary symptom questionnaire, URP measurement and urodynamic evaluation between February and July 2004. The URP mean values were compared with urinary symptoms and urodynamic diagnoses, using the independent t test correction for multiple measurements. MAIN OUTCOME MEASURES: Retrograde URP, urodynamic diagnoses and urinary symptoms. RESULTS: One hundred and eighty-five women were recruited. Women with urodynamic stress incontinence (USI) have significantly lower URP than women with competent urethral sphincters (P < 0.05, independent t test). Women with mixed urodynamic incontinence had values of URP intermediate between women with detrusor overactivity (DOA) and those with USI. In the mixed group, URP mean values were not significantly different from those with DOA and competent sphincters or USI (P > 0.05, independent t test). There was no significant difference between mean URP values and different urinary symptoms (P > 0.05, independent t test). CONCLUSIONS: There are significantly different URP measurements between women with DOA and those with USI. However, the URP is not a diagnostic tool.