Sphincteric Urinary Incontinence: Relationship of Vesical Leak Point Pressure, Urethral Mobility and Severity of Incontinence

Abstract

We examined the relationships among urethral hypermobility, intrinsic sphincter deficiency and incontinence in women. A total of 65 consecutive women with stress urinary incontinence and 28 with lower urinary tract symptoms not associated with stress urinary incontinence were evaluated with videourodynamics, 24-hour voiding diaries and pad tests, vesical leak point pressure measurement and the cotton swab test. A total of 93 patients with a mean age +/- SD of 63 +/- 13 years were studied, including 65 who presented with stress urinary incontinence and 28 who presented with lower urinary tract symptoms without stress urinary incontinence. The incidence of urethral hypermobility was 32% in the stress urinary incontinence group and 36% in the lower urinary tract symptoms group (p = 0.46). When stress urinary incontinence cases were stratified according to a vesical leak point pressure of 0 to 60, 60 to 90 and greater than 90 cm. H2O, urethral hypermobility was noted in 25%, 31% and 41%, respectively, a difference that was not statistically significant (p = 0.6). Overall incontinent patients with and without urethral hypermobility had the same median number of incontinence episodes (5, range 1 to 13 versus 7, range 1 to 15, p = 0.39) and median pad weight (39.5 range 1 to 693 gm. versus 33.5, range 1 to 751, p = 0.19). When patients with intrinsic sphincter deficiency, defined as vesical leak point pressure less than 60 cm. H2O, were divided into those with and without urethral hypermobility, there were no differences in the mean number of incontinence episodes (9.4 +/- 3 versus 6 +/- 3.6, p = 0.17) or median pad weight (90 gm., range 10 to 348 versus 86, range 30 to 81, p = 0.76). The degree of change in the urethral angle did not correlate with vesical leak point pressure (r = 0.16, p = 0.24) or with pad weight (r = -0.23, p = 0.1). Urethral hypermobility was equally common in this group of women with lower urinary tract symptoms and stress urinary incontinence. Intrinsic sphincteric deficiency and urethral hypermobility may coexist and they do not define discrete classes of patients with stress urinary incontinence. Urethral hypermobility did not appear to have an independent effect on the frequency or severity of incontinence. Patients with stress urinary incontinence can still be characterized by vesical leak point pressure and change in the urethral angle, although these variables do not always define discrete classes.