Valsalva leak point pressure to determine internal sphincter deficiency in stress urinary incontinence

Valsalva leak point pressure (VLPP) represents the global competence of the conjunctive forces around the urethra to support increased pressure from the abdominal cavity with transmission to the bladder. Assessment of VLPP has prognostic meaning, but measurement techniques are still subject to controversy.

One hundred and eight consecutive women with no genital prolapse or bladder hyperactivity exclusively presenting with urinary stress incontinence were submitted to VLPP determination during urodynamic evaluation using a rectal and urethral catheter. Rectal pressure measurement served as the landmark in the determination of Valsalva's maneuver. After determining the rectal pressure, the urethral probe was pulled out and the maneuver repeated.

Eighty-four cases (group I) presented leakage during Valsalva's maneuver with the urethral catheter being in place. Group Ia (66.6%) had a reduction of 44.5 cm H(2)O in the rectal pressure after catheter removal. In group Ib, rectal leakage pressure increased after catheter removal from 76.5 +/- 18.7 to 79.5 +/- 24.7 cm H(2)O. Eight patients did not demonstrate urine leakage after catheter removal. In group II, 24 cases showed a rise in rectal leakage pressure to 76.2 +/- 22 cm H(2)O, but urinary leakage was only observed after catheter removal. In group IIa (19 cases), the VLPP decreased by 12.6 +/- 15 cm H(2)O, while in group IIb (5 cases) leakage occurred only in patients showing an increase of 22.2 +/- 7 cm H(2)O in the rectal pressure after the second maneuver with the urethral catheter in position.

Precise determination of the abdominal leak point pressure through Valsalva's maneuver may be critical. The different techniques used for VLPP determination may render comparisons difficult. Rectal pressure measurement with no urethral catheter in place to monitor abdominal leak pressure seems to be more appropriate because it resembles clinical practice. Although lower abdominal leakage pressures may be found, this is not a uniform finding, and a higher incidence of type III incontinence may be expected, and critical analysis or painstaking repetition may be required in the case of lack of demonstration of urinary loss.