Clinical and urodynamic features of intrinsic sphincter deficiency

A prospective analysis of 92 patients with genuine stress incontinence was performed to identify the clinical and urodynamic features of intrinsic sphincter de¢ciency (ISD). Methods: We divided the patients into two categories: 50 patients a¡ected by pure ISD as they had severe stress incontinence and no urethral mobility; 42 patients su¡ering from stress urinary incontinence without ISD as they had mild stress incontinence and marked urethral hypermobility. Cystometry was normal in all patients. The presence/absence of ISD was considered the dependent variable and was correlated against the following independent variables: age, vaginal deliveries, menopause, previous urogynecological surgery and/or hysterectomy, supine stress test, irritative and/or obstructive symptoms, Valsalva leak point pressure (VLPP), maximum urethral closure pressure (MUCP), urethral functional length (UFL), and leakage during cystometry. Results: The statistical analysis showed close correlations between ISD and age (P < 0.001), menopausal status (P < 0.001), previous surgery (P < 0.0001), supine stress test (P < 0.0001), leakage during cystometry (P < 0.001), and UFL (P < 0.01). The VLPP was below the cut-o¡ value (60 cm H2O) in 70% of ISD patients (P < 0.0001), whereas the MUCP in 50% of ISD patients (P < 0.0001). Multiple logistic analysis showed that lower VLPP, lower MUCP, and previous surgery correlate more signi¢cantly with ISD. After backward conditional stepwise logistic regression, the odds ratio of having ISD were VLPP ¼ 2.3, MUCP ¼ 7.7, VLPP þ MUCP ¼ 62.8. Conclusions: ISD is related to the presence of a more severe clinical picture and case history, but the most signi¢cant independent variables are theVLPP and MUCP.