[Valsalva leak point-pressure (LPP) and maximal urethral closure pressure (MUCP) in women with stress urinary incontinence (SUI)]. / Valsalva leak point-pressure (LPP) e massima pressione di chiusura uretrale (MUCP) in donne con incontinenza urinaria da stress (IUS).

ABSTRACT

One-hundred and twenty-two women with USI have been evaluated with clinical examination and urodynamics and divided in two groups only in 74 patients with urinary loss during the Valsalva manoeuvre, LPP was compared to MUCP by linear regression analysis and its ability (cut-off = 60 cmH2O) to predict a MUCP < or = 20 cmH2O was tested. Weak correlations were observed between MUCP and LPP (r = 0.56). Fifty-two patients presented a LPP < or = 60 cmH2O, in 6 of them MUCP was < or = 20 cmH2O; none with LPP > 60 cmH2O showed a MUCP < or = 20 cmH2O. Median MUCP and intravesical pressures at the instant of leakage of patients with LPP < or = 60 cmH2O were significantly different from those of patients with LPP > 60 cmH2O (p < 0.01). The specificity and positive predictive value of LPP < or = 60 cmH2O for the detection of a "low pressure urethra" were respectively 32% and 11.5%, while sensibility and negative predictive value were 100%. LPP can not be regarded as a specific test for urethral sphincteric deficits. For its sensibility, it can be an useful screening tool for patients at high risk of type III urinary incontinence.