Urodynamic Study Of The Female Bladder Outlet Obstruction

Objective To investigate the urodynamic changes of female bladder outlet obstruction (FBOO) and the clinical use of urodynamic examination.Methods Fifty-seven female outpatients with mean age of 52.3 (21 to 76 years) in the first affiliated hospital of Nanchang University were considered skeptically with BOO according to their clinical presentations. The chief complaints included frequency, urgency, dysuresia, flow delay and other LUTS(Low Urinary Tract Symptoms). All patients had intact history documents which included the results of cystoscopy and cystourethrography examination, and showed no history of neurogenic disease, diabetes mellitus, pelvic surgery, urethral surgery or trauma and genitourinary infection or deformity. All patients had no caruncula urethae, urethrocele, hysteroptosis, paraurethral gland adenocele. Four cases were found with bladder diverticulum discovered by cystoscopy and 2 with renal function damage. Urodynamic studies were performed in all patients and the parameters included those which were flow rate, volume of residual, Qmax, Pdet.Qmax, Pdet.max, CMG, MUCP. In this study, the diagnostic criteria of radiographic BOO was that the bladder neck was close or narrowed during voiding, or the existence of stricture of distal urethrae and the concomitant dilatation of proximal urethrae. Cystoscopic features of BOO was the elevation of the posterior bladder neck, just like a dam. If the detrusor pressure <40 cmH2O without the existence of BOO, detrusor underactivity was confirmed.Results Thirty-five cases were diagnosed with FBOO. The urodynamic data in FBOO group showed that mean Qmax was 9.26±2.53ml/s , mean RV was 95.74±119.65 ml, mean Pdet.Qmax 37.51±9.46cmH2O, mean Pdet.max 58.33±14.56cmH2O, mean MUCP 82.22±19.08 cmH2O. While 22 cases were confirmed with non-BOO (17 of them showed female detrusor underactivity and 5 cases were normal) with mean Qmax 12.29±4.68ml/s , mean RV 83.50±152.69 ml, mean Pdet.Qmax 16.57±5.56cmH2O, mean Pdet.max 30.57±8.30cmH2O, mean MUCP 52.27±18.17 cmH2O. The statistic analysis showed that Qmax of FBOO group was significantly lower than that of non-BOO group (P<0.05), while the Pdet.Qmax,Pdet.max,MUCP of FBOO group were significantly higher than those of non-BOO group(P<0.01).Conclusions Typical Urodynamic changes of FBOO included high detrusor pressure while low flow rate. LUTS and low flow rate was not specific for FBOO. Urodynamic examination was very important for the diagnosis of FBOO, especially with combination of cystoscopy and/or cystourethrography.