The Effectiveness of Cystography-Measured Bladder Neck Elevation at Predicting the Return of Continence After Robot-Assisted Radical Prostatectomy

Abstract

PURPOSE: To analyze the clinical parameters correlated with early recovery of urinary continence after radical prostatectomy, with a focus on urethral mobility during pelvic contraction at catheter removal. METHODS: We prospectively analyzed 67 patients who underwent prostatectomy for prostate cancer at Jeju National University Hospital from January 2015 to June 2018. At the time of catheter removal, a cystography was performed in 67 men (median age, 65 years; range, 55-76 years) who had undergone robot-assisted laparoscopic prostatectomy. The vertical length of bladder neck movement between relaxing and contracting the pelvic muscles was measured. The correlation between the rate of continence recovery and the length of urethral movement was also assessed. All participants were divided into 2 groups according to the length of bladder neck elevation. Group 1 had ≥0.6 cm of elevation, while group 2 demonstrated <0.6 cm of elevation. RESULTS: A reverse correlation existed between the length of urethral movement and the recovery rate of urinary continence (r=-0.488, P<0.001). The optimal cutoff value for length of urethral movement was found to be 0.6 cm among patients (area under the curve, 0.703). A statistically significant difference was observed between group 1 (length≥0.6 cm) and group 2 (<0.6 cm) (P<0.05). Multivariate regression analysis showed that urethral movement predicted the postoperative urinary incontinence. CONCLUSION: The extent of bladder neck elevation after robot-assisted laparoscopic prostatectomy, which can be easily evaluated using cystography, may be a good predictor of the recovery of urinary continence.