The effect of urethral calibration on female primary bladder outlet obstruction

While primary bladder outlet obstruction (BOO) in women has become an increasingly recognized entity over the past few years, the optimal management for such condition is yet to be defined. We assessed the effect of urethral calibration in the treatment of female BOO.

A retrospective review of female patients undergoing urethral calibration with urethral dilator for BOO from 2000 to 2009 was performed. BOO was defined as a maximum flow rate (Qmax) of less than 15 ml/s together with a detrusor pressure at maximum flow rate (PdetQmax) of more than 20 cmH₂O in urodynamic studies in the absence of neurological disorders or mechanical causes. Pre-calibration and post-calibration urodynamic studies were compared.

Twenty women were diagnosed of BOO on urodynamic criteria (mean age 56 ± 14 years). Sixty percent of the patients had obstructive symptoms, while 50% of them had irritative symptoms. Reassessment urodynamic studies were performed 6 months after urethral calibration. Although there was no significant change in Qmax and post-void residual urine after urethral calibration (9.6 ± 2.8 vs 9.7 ± 4.0 ml/s, p = 0.869 and 246 ± 196 vs 263 ± 198 ml, p = 0.753, respectively), PdetQmax significantly improved (72.2 ± 39 vs 50.2 ± 30.5 cmH₂O, p = 0.013). Only one patient developed urinary tract infection after the procedure. No complication of incontinence had been observed. Among the 20 patients, 13 patients (65%) had a second urethral calibration after the reassessment urodynamic study for persistent symptoms.

Female patients with bladder outlet obstruction showed improvement in the urodynamic parameters after urethral calibration. However, its durability is not certain yet. Future studies concerning clinical symptoms correlation with urodynamic parameters would help further delineate the role of urethral calibration in the management of bladder outlet obstruction in women.