Removal of transurethral catheter during urodynamics may unmask stress urinary incontinence

The measurement of Valsalva leak point pressure may have an important role in the treatment algorithm of women with stress urinary incontinence. However, some patients with stress urinary incontinence may not have leakage during standard urodynamic studies and, thus, the Valsalva leak point pressure cannot be determined. We hypothesized that the transurethral catheter may inhibit leakage during urodynamics.

We evaluated 21 consecutive women presenting with complaints of stress urinary incontinence who failed to have leakage on urodynamic studies. Bedside cystometry was performed, followed by urodynamics using a 6Fr transurethral catheter. When stress urinary incontinence was not noted, the catheter was removed and the Valsalva leak point pressure was measured using the intraabdominal pressure catheter.

No woman had leakage on urodynamic studies with the catheter in place, although 11 of 21 had leakage after the catheter was removed and 15 had leakage on bedside cystometry. All 11 patients with leakage at catheter removal showed leakage on bedside stress testing. Mean Valsalva leak point pressure in those with leakage was 67 cm. water.

Patients with a history of stress urinary incontinence and those with a positive bedside stress test who do not have leakage during a Valsalva maneuver on urodynamic studies should repeat the Valsalva maneuver with the catheter out. This technique may unmask stress urinary incontinence and allow the measurement of Valsalva leak point pressure.