Impact of bladder neck angle measured by postoperative magnetic resonance imaging on mid-term recovery of urinary continence in prostate cancer patients undergoing robot-assisted radical prostatectomy

Abstract Purpose Studies regarding predictive factors of urinary continence following Retzius-sparing radical prostatectomy is limited. This study was designed to evaluate association of urethral parameters on preoperative magnetic resonance imaging (MRI) and immediate recovery of urinary continence following Retzius-sparing robot assisted radical prostatectomy (RS-RARP). Materials and Methods This retrospective cohort study enrolled 156 patients with clinically localized prostate cancer who underwent MRI before RS-RARP. We measured the following structures on preoperative MRI: minimal residual membranous urethral length (mRUL), peri-urethral sphincter complex (PSC) thickness, urethral wall thickness (UWT), the thicknesses of the levator ani muscle (LAM) and obturator internus muscle (OIM). Immediate urinary continence was defined as patients reported freedom from using safety pad within 7 days after removal of urinary catheter. Patients were divided into two groups according the median of each parameter on MRI. We retrospectively analyzed the patients in term of preoperative clinical factors and postoperative urinary continence. Results A total of 100 patients (64.1%) reported immediate urinary continence after RS-RARP. Immediate urinary continence was significantly more in patients with longer mRUL (≥ 8.70 mm) than in patients with shorter mRUL (< 8.70 mm; P= 0.000). On multivariable analysis, longer mRUL was significantly related to immediate urinary continence after RS-RAPA (odds ratio, 8.265, P= 0.000). PSC, UWT, LAM and OIM were not associated with immediate urinary continence. Conclusions Our results firstly demonstrated that preoperative mRUL measured on MRI was an independent predictor of immediate urinary continence following RS-RARP. Therefore, preservation of membranous urethra is still the anatomical basis of better urinary outcome after RS-RARP.

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Improvement in early urinary continence recovery after robotic-assisted radical prostatectomy based on postoperative pelvic anatomic features: a retrospective review

BMC Urology ◽

10.1186/s12894-019-0519-8 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 1

Author(s):

Akihiro Nakane ◽

Hiroki Kubota ◽

Yusuke Noda ◽

Tomoki Takeda ◽

Yasuhiko Hirose ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Radical Prostatectomy ◽

Odds Ratio ◽

Bladder Neck ◽

Urinary Continence ◽

Resonance Imaging ◽

Robotic Assisted ◽

Neck Width ◽

Robotic Assisted Radical Prostatectomy

Abstract Background We investigated the impact of postoperative membranous urethral length and other anatomic characteristics of the pelvic floor shape as measured by magnetic resonance imaging on the improvement in continence following robotic-assisted radical prostatectomy. Methods We retrospectively reviewed data from 73 patients who underwent postoperative prostate magnetic resonance imaging following robotic-assisted radical prostatectomy between 2013 and 2018. Patient demographics; pre-, peri-, and post-operative parameters; and pelvic anatomic features on magnetic resonance imaging were reviewed. Patients who used no urinary incontinence pads or pads for protection were considered to have achieved complete continence. Results Urinary continence was restored in 27.4, 53.4, 68.5, and 84.9% of patients at 1, 3, 6, and 12 months after robotic-assisted radical prostatectomy, respectively. When patients were divided into early and late continence groups based on urinary continence at 3 months after robotic-assisted radical prostatectomy, no significantly different clinical characteristics or surgical outcomes were found. However, the mean membranous urethral length (18.5 mm for the early continence group vs. 16.9 mm for the late continence group), levator muscle width (7.1 vs. 6.5 mm, respectively), and bladder neck width on the trigone side (7.2 mm vs. 5.4 mm, respectively) were significantly different between groups (all p < 0.05). Multivariate logistic regression analysis showed that membranous urethral length (odds ratio, 1.227; 95% confidence interval, 1.011–1.489; p = 0.038) and bladder neck width (odds ratio, 1.585; 95% confidence interval, 1.050–2.393; p = 0.028) were associated with the period of early urinary continence. Conclusions Postoperative membranous urethral length and bladder neck width were significantly associated with early urinary continence recovery after robotic-assisted radical prostatectomy. It is highly recommended that surgeons focus on preserving the membranous urethral length and increasing the bladder neck width on the trigone side during surgery to achieve optimal continence outcomes after robotic-assisted radical prostatectomy.

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