Women with voiding dysfunction may result from detrusor underactivity (DU), bladder neck dysfunction (BND), dysfunctional voiding, poor relaxation of external sphincter, or urethral stricture. Using videourodynamic study (VUDS) a tight or non-funneling bladder neck can be observed in women with voiding dysfunction. Transurethral incision of the bladder neck (TUI-BN) is recommended to relieve the bladder neck resistance and facilitate voiding. This study investigates the treatment outcome and searches for predictive factors for a successful outcome in women with neurogenic or non-neurogenic voiding dysfunction after TUI-BN.

A total of 141 women treated with TUI-BN were investigated. VUDS was routinely performed to demonstrate a non-opening or non-funneling bladder neck with or without detrusor contraction.  TUI-BN was performed by incisions of the bladder neck at 5 and 7 o’clock position under anesthesia. If patients can empty their bladder efficiently (voiding efficiency [VE] > 67%), the treatment was considered satisfactory (GRA=2) and excellent (GRA=3) for VE >90%. Repeat VUDS was performed for the presence of DU or a tight urethral sphincter. Urethral sphincter BoNT-A injection was performed to facilitate an efficient voiding. The treatment outcome of patients with a successful and failed TUI-BN and the factors to predict a successful outcome were analyzed.

Among the women, a successful treatment outcome (GRA=2 or 3) was achieved in 86 (61.0%) and failed in 55 (39.0%). The mean age mean was 66.7 ± 14.6 years (28-95) with no difference between groups. The baseline clinical demographics and VUDS diagnosis are shown in Table 1. A successful outcome was achieved in 45 (54.2%) of patients with DU, in 54 (62.8%) of patients with BND, and 11 (64.7%) of patients with PRES or DV. There is no significant difference between patients with and without central nervous system diseases, or between patients with previous pelvic or spine surgery. After TUI-BN, the maximum flow rate, voiding detrusor pressure, voiding efficiency, and bladder outlet obstruction index all showed significantly improved in successful treatment subgroup compared with the failed subgroup. Among the 31 women who failed TUI-BN, urethral BoNT-A injection was successful to achieve a successful outcome in 9 (29.0%) women. However, 9 women developed stress urinary incontinence needing suburethral sling or platelet-rich plasma injection to regain continence, and 7 of 9 (77.8%) could achieve a successful treatment outcome. Multivariable analysis revealed a p value was 0.074 for DU as a marginal predictive factor for a treatment failure (Table 2).

This study demonstrated that 61.0% of women with neurogenic or non-neurogenic voiding dysfunction and non-opening bladder neck during VUDS can benefit from TUI-BN. Among the patients, patients with VUDS proven DU had a lower successful rate. Although the treatment outcome was not as high as expected, 29.0% of women failed the initial TUI-BN still can achieve a successful outcome after urethral sphincter BoNT-A injection. Patients with normal detrusor contractility and BND can achieve a successful outcome through reduced bladder outlet resistance, whereas patients with DU still can have a satisfactory result by a lower abdominal pressure study to achieve a higher voiding efficiency of urination.

TUI-BN is effective to achieve a successful outcome for women with neurogenic or non-neurogenic voiding dysfunction. A successful rate was 61.0%. Patients with VUDS proven DU had a lower successful rate, but 54.2 % of them still can have a satisfactory urination after TUI-BN. In women who failed the initial TUI-BN, urethral sphincter BoNT-A injection can further improve the treatment outcome, suggesting the urethral sphincter dysfunction might concomitantly contribute to voiding dysfunction in women with a tight bladder neck.