Purpose: To describe our bladder neck dissection during robot-assisted radical prostatectomy (RARP), to describe the degrees of robot-assisted bladder neck preservation (R-BNP) we have encountered, and to determine the effect of increasing R-BNP on postoperative continence and positive surgical margin (PSM) rates.
Patients and methods: We performed a retrospective analysis of 599 patients who underwent robot-assisted radical prostatectomy (RARP) by a single surgeon (DIL). All bladder neck dissections were graded between 1 and 4; higher grades corresponded to an increasing degree of robot-assisted bladder neck preservation (R-BNP). After grouping patients by R-BNP grade, postoperative continence and positive surgical margin (PSM) rates were compared. The association between R-BNP and continence was also assessed using multivariate binary logistic regression models.
Results: Similar outcomes were seen for two definitions of continence (0 pads per day [ppd]; 0 ppd or security pad, respectively). A higher proportion of patients were continent at 3 months postoperatively who received grade 4 compared with grade 1 (P=0.043; P=0.001) and grade 2 (P=0.006; P=0.009); and grade 3 compared with grade 1 (P=0.048; P=0.002) and grade 2 (P=0.009; P=0.030) R-BNP. There was no difference between grade 1 and 2 (P=0.541; P=0.064), and grade 3 and 4 (P=0.898; P=0.584) R-BNP. At 1 year postoperatively, there was no difference among the four groups in continence rate (P=0.771; P=0.411). R-BNP was an independent predictor of continence at 3 months (odds ratio [OR] [95% confidence interval (CI)]=1.33 [1.06-1.67]; OR [95% CI]=1.45 [1.1-1.82]), but not at 1 year (OR [95% CI]=1.07 [0.82-1.39]; OR (95% CI)=1.30 [0.92-1.85]). There was no difference among the four groups in PSM rates (P=0.946).
Conclusions: R-BNP is a graded, rather than all-or-none outcome. An increasing degree of R-BNP is associated with an earlier return to continence, without compromising oncologic outcomes.