Objective assessment of resistance of female urethra to stress. A scale to establish degree of urethral incompetence.

During urethral pressure profile (UPP) studies under gradually increasing stress, the maximum urethral closure pressure decreases. This observation led to a simple urodynamic test which allows the estimation of the maximum stress (intensity of cough) tolerated by the urethra before leakage begins. The determination of this critical pressure forms the basis of the urethral incompetence scale. The urethra of a female patient can be characterized by the amplitude of this maximum stress (in cm H2O) the urethra can handle and still remain continent. The cough intensity scale has been divided into 5 segments, defining 5 degrees of urethral incompetence. The critical pressure, which determines the degree of urethral incompetence is a constant value for a given patient, provided the bladder volume is kept constant and the position of the patient during the examination is unchanged. This method establishes the functional status of the female urethra as far as its sphincteric capabilities are concerned under different stress conditions. It represents the degree of pressure transmission from the abdominal cavity to the proximal urethra during stress. It evaluates objectively the functional results of different surgical or medical therapeutic modalities to cure genuine stress incontinence. It allows a better selection of patients with unstable bladder and genuine stress incontinence who will more likely benefit from a retropubic cystourethropexy.