The best treatment solution in organ confined muscle invasive bladder cancer (MIBC) is still represented by radical cystectomy (RC) associated to pelvic lymph-node (LND) dissection and urinary diversion. When feasible, the replacement of the bladder with a urinary diversion allowing to void through the native urethra is an attractive challenge. Multiple approaches for total intracorporeal neobladder (ICNB) reconstruction have been reported during robot-assisted-radical-cystectomy (RARC), emulating the steps of open surgery or attempting to simplify them. The aim of this study was to describe urodynamics (UD) findings of our robotic Y-ICNB technique.

In this perspective study we enrolled 45 patients affected by MIBC (T1-T4N0-N1M0) from 01/2017 to 06/2021 at our tertiary center. All the patients underwent robotic radical cystectomy (RARC) with Y-ICNB reconfiguration.
We excluded from the study all patients with pathological confirmation of tumor in the prostatic urethra, indication to treatment without curative intent (cT4b, salvage or palliative cystectomies) and presence of urethral strictures. Continence at 1, 3, 6 and 12 months were evaluated. At the 3rd month of follow-up patients underwent UD. Finally, in a retrospective match paired analysis the functional outcomes of Y RARC patients were compared with a cohort of open Y radical cystectomy.

UDs revealed median neobladder capacity of 268 ml, with a median compliance of 13 ml/cm H20; the voiding phase showed a voiding volume and a post void residual (PVR) of 154 cc and 105 cc respectively. At 12 months of follow-up 4.4%, 15.5% and 4.4% of the patients experienced urge, stress and mix urinary incontinence respectively.

We observed satisfying UD functional outcomes, both during filling and voiding phase. The comparison between Y RARC and Y open RC revealed a higher neobladder capacity with open approach (268 ml vs 299 ml; p=0.049) with subsequent better findings during the voiding phase in terms of maximum flow (9,2 ml/s vs 13,7 ml/s; p= 0.002), voiding volume (154 ml vs 236 ml; p= 0.001) and PVR (105 ml vs 54,7 ml; p= 0.01). The reason could be an easier management of the bowel with the open approach that allows surgeon to measure more precisely the distance among the intestinal loops with a subsequent more voluminous reservoir. Focusing on continence recovery, a slight trend in favor of RARC was shown without reaching the statistical significance (table 1).

Our work reveal that this kind of total intracorporeal Y neobladder is characterized by satisfying urodynamics functional outcomes as proven by the adequate neobladder capacity, low-pressure storage and high compliance during the filling phase and low post void residual after the voiding phase.