Prediction of Stress Urinary Incontinence Using the Retrovesical (β) Angle in Transperineal Ultrasound

Objectives The accurate, rapid diagnosis of stress urinary incontinence (SUI) in women can profoundly improve their sexual and psychosocial life. In this study, the diagnostic power of SUI was assessed by transperineal ultrasound. Methods In this hospital-based case-control study, married women who were referred to the gynecologic and ultrasound wards with negative urinalysis and culture results were enrolled by random sampling. Patients with positive cough signs based on the urodynamic testing data were considered cases, whereas control women showed no cough symptoms and were recruited from the same ward. Results There was a significant difference (P< .001) in bladder neck descent (mean +/- SD, 10.89 +/- 5.51 versus 7.08 +/- 2.60 mm, respectively; P = .0001) and the retrovesical (beta) angle with the Valsalva maneuver (144.22 degrees +/- 19.63 degrees versus 111.81 degrees +/- 24.47 degrees;P< .001) between the case and control groups. Also, the beta angle without the Valsalva maneuver was higher in the case group (112.35 degrees +/- 23.10 degrees) than the control group (120.17 degrees +/- 25.16 degrees;P= .001). There was no case of a urinary leak, urethral diverticulitis, a bladder stone or mass, and cystourethrocele in the patients of each group. The results of multivariate logistic regression with a backward method showed that bladder neck descent (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.09-1.40), the beta angles with and without the Valsalva maneuver (OR, 1.1; 95% CI, 1.06-1.13; and OR, 1.04; 95% CI, 1.01-1.06) were the predictors of SUI. A beta angle higher than 127 degrees with the Valsalva maneuver, with an area under the curve of 0.89 (95% CI, 0.75-0.96), could very well predict the SUI response. This finding shows that it can be very well used to distinguish between normal and non-normal responses, with 89% sensitivity and 79% specificity. Conclusions The beta angle with the Valsalva maneuver could very well predict the SUI response.