Background and purpose: In order to characterize the etiology of bladder outlet obstruction (BOO) in Taiwanese women, the results of videourodynamic studies performed in women with lower urinary tract symptoms (LUTS) were analyzed. The treatment results were compared with the underlying pathophysiology among the three etiologies of urethral stricture, spastic urethral sphincter, and cystocele.
Methods: From October 1997 through February 1999, 364 female patients underwent videourodynamic study to investigate the underlying etiology of LUTS. BOO was defined as a voiding detrusor pressure of 50 cm H2O or greater and a narrow urethra on the voiding cystourethrography. Cystoscopy, urethral sounding, and external sphincter electromyography were used in conjunction with the pressure/flow findings for differential diagnosis of the etiology of BOO.
Results: Among the 364 patients with LUTS who underwent videourodynamic study, 35 (9.6%) had BOO. Detailed investigation revealed that 15 of these women had urethral stricture (43%), 14 had spastic urethral sphincter (40%), and six had cystocele (17%). No significant difference was found in the urodynamic parameters among these three groups of patients. The incidence of bladder trabeculation and urge incontinence was significantly higher in patients with urethral stricture. Improvement of urine flow and voiding symptoms was achieved in 87% of the patients with urethral stricture, 50% female patients with spastic urethral sphincter, and 100% of those with cystocele.
Conclusions: The results suggest that BOO is not uncommon in women with LUTS, and that a correct diagnosis of BOO should be based on comprehensive urodynamic study.