PREDICTING INTRINSIC URETHRAL SPHINCTER DYSFUNCTION IN WOMEN WITH STRESS URINARY-INCONTINENCE

Objective: To determine whether specific clinical characteristics can be used to identify women with stress urinary incontinence due to intr insic urethral sphincter dysfunction without the aid of urodynamic tes ting. Methods: A retrospective analysis was performed of 263 consecuti ve patients who underwent complete urodynamic evaluation for complaint s of urinary leakage. Intrinsic sphincter dysfunction was defined as a maximum urethral closure pressure of 20 cm H2O or less in the sitting position at maximum cystometric capacity. Women with sphincter dysfun ction were then compared to the group with normal pressure (greater th an 20 cm H2O) using t test, chi(2), and logistic regression analyses f or 13 clinical indices, endoscopic appearance of the proximal urethra, and eight urodynamic criteria. Results: The group with intrinsic sphi ncter dysfunction totaled 132 women (50.2%). Univariate analysis revea led that women in this group were older and were more likely to have u ndergone a hysterectomy and at least one anti-incontinence procedure c ompared to the women with normal urethral pressure. However, multivari ate analysis revealed that age greater than 50 years was the only inde pendent variable that could predict the presence of intrinsic sphincte r dysfunction in women with stress incontinence (odds ratio 1.6, 95% c onfidence interval 1.2-2.2). The two groups were similar in all other preoperative clinical characteristics. Conclusions: The only preoperat ive clinical index that predicted the presence of intrinsic urethral s phincter dysfunction, as defined by low urethral closure pressure, was age over 50 years. In view of previous studies reporting a higher rat e of surgical failure in women with low urethral pressure, urodynamic testing should be considered in surgical candidates over age 50 to all ow adequate preoperative counseling.