Value of testing the abdominal leak point pressure in the differential diagnosis of urinary stress incontinence

INTRODUCTION: The two main reasons of stress incontinence, according to the present consensus, are urethral hypermotility due to descended bladder floor and intrinsic sphincter deficiency. Distinction between them used to be achieved by determining urethral pressure profile only. In recent years a less invasive method, measuring the Valsalva Leak Point Pressure, has been developed for a differentiation. AIMS: To determine Valsalva Leak Point Pressure using a simple technique for differential diagnosis of stress incontinence without a complete urodynamic test. METHOD: A minimally invasive technique is presented. Authors have performed parallel measurements of leak point pressure and urethral pressure profile during urodynamic examination in 43 stress incontinent patients. Difference in the results have also been evaluated. RESULTS: A specificity of 98% and a sensitivity of 51% with the method was found in intrinsic sphincter deficiency. In cases without vaginal descent the sensitivity was 100%, while in patients with urethral hypermobility the sensitivity and the specificity were 91% and 58% respectively. CONSEQUENCES: In stress incontinent patients without urethral hypermotility an abdominal leak point pressure of less than 40 H2O cm perfectly reflects weakness of the urethral sphincter. Based on these data we suggest that the invasive urethral pressure profile test can be avoided in appr. 20% of stress incontinence cases by weakness of the sphincter.