Surgical experience overcomes the impact of prostatic-urethral anatomy on continence recovery after robotic prostatectomy: comprehensive analysis on 366 cases

Purpose: To investigate the relationship between a set of prostate-urethral complex (PUC) measurements and incontinence after robot-assisted radical prostatectomy (RARP). Methods: The study included data from patients undergoing RARP performed by 2 expert surgeons between 2019 and 2022, with data about preoperative magnetic resonance imaging (MRI) and functional follow-up. Continence status was assessed according to a stringent definition (no PADS used). MRIs were evaluated to calculate prostatic urethral length, membranous urethral length, membranous urethral width, levator ani thickness, and prostate shape. The association of PUC measurements with continence after RARP was studied. Secondarily, we evaluated whether pre-determined cut-off values of PUC measurements could be associated with time to continence. Cumulative hazard incidence analysis was performed by the Nelson-Aalen hazard function. Cumulative incidence hazard curves were built; the Peto-Peto test was used to evaluate the difference among the curves. Results: 366 patients were included. At the 12-month follow-up, 333 patients (90.1%) were continent. Classification of PUC measurements overlapped between continent and noncontinent patients. However, a statistically significant difference was observed for levator ani thickness, greater in continent patients (12.8 mm vs. 11.7; p = 0.02). Multivariable models found BMI as independent predictor of incontinence (HR 1.04, 95% C.I 1.00-1.07, p = 0.04). None of PUC measurements associated with incontinence. Also, cumulative hazard incidence analysis at 3 / 6 / 12-months found no statistically significant difference in PUC measurements. Conclusion: No association was found between anatomical characteristics of PUC and continence or time to continence after RARP performed by proficient surgeons. Our data would suggest that once the surgeon has surpassed the learning curve, anatomical variations do not significantly affect the appropriate and proficient execution of the prostate apex dissection during RARP.