Objective: To investigate perioperative and mid-term functional outcomes of stentless FloRIN reconfiguration as compared to standard technique performed with ureteral mono J placement.

Patient and dataset Clinical and surgical data of all consecutive patients treated at our Institution from January 2021 to February 2022 with RARC, lymph node dissection (LND) and FloRIN reconfiguration were gathered in this single institution randomized 1:1 prospective series. All patients with clinical stage T1-T4N0-N1M0 amenable to radical cystectomy with curative intent and FloRIN reconfiguration were included. The sample size for a non-inferiority trial was calculated for different endpoints. Preoperative work-up included chest and abdomen contrast-enhanced computed tomography (CT) scan. Main exclusion criteria were: 1) presence of one or multiple tumor metastases at preoperative staging; 2) histopathological confirmation of bladder tumor at the level of prostatic urethra; 3) treatment without curative intent (cT4b, salvage or palliative cystectomies); 4) presence of urethral stricture. After preliminary multidisciplinary evaluation, patients were randomly assigned with 1:1 ratio to the mono-J stent placement or the stentless group. For the present study, only patients with a minimum 6 month-follow up were evaluated. Patient demographics, including ASA score and Charlson Comorbidity Index (CCI), peri- and postoperative features including operative time, conversion rate, estimated blood loss (EBL), Visual Analogue Scale (VAS) pain intensity scale, length of hospital stay (LOS) early (≤30 days) and delayed (>30 days) complications rate, and pathological data were thoroughly gathered.

Follow-up schedule included blood analysis and CT scan performed three months after surgery, then every 6 months from the first to the third postoperative year, followed by annual imaging assessment according to individual risk profile, as postulated by the EAU guidelines. In case of newly diagnosed postoperative hydronephrosis, only patients with grade > 2 or symptomatic were assessed as functional failure. All eligible patients were offered the possibility to undergo neoadjuvant cisplatin-based chemotherapy before RARC. Patients with non-muscle invasive bladder cancer, cN+ disease and those presenting with severe cardiovascular morbidity or high preoperative creatinine levels, strongly contraindicating cisplatin administration, underwent immediate radical cystectomy. The enhanced recovery after surgery protocol (ERAS) was regularly applied. Suitable patients underwent a nutritional assessment with a specific immune-nutrition, 7 days preoperatively.

Surgical technique All robotic surgical procedures were performed by a single highly experienced robotic surgeon (AM) alternated with the other fellow-members. The Da Vinci Si system, (Intuitive Surgical, Sunnyvale, CA, USA), in a four-arm configuration with a 0/30° laparoscope was used for all cases. As previously described (4), patients are positioned in 30° Trendelenburg with a standard six-port transperitoneal approach for the demolitive part and then reduced to 20° to facilitate bowel handling and urethro-neobladder anastomosis. After the isolation of 45-50 cm of ileum, the urethro-ileal anastomosis is performed obtaining an asymmetrical 'U'-shape (25-30 cm distally and 20 cm proximally to anastomosis). Ileum is then sectioned by endo- GIA 60 mm Echelon Powered Endopath Stapler (Ethicon Inc., Cincinnati, OH, USA) and the intestinal continuity is then restored with an intracorporeal side-to-side anastomosis with one longitudinal fire. The two transversal holes are closed by a double layer 3-0 Stratafix running suture. The asymmetrical 'U'-shape segment is then detubularized and the posterior plate is reconfigured as an "Γ", by suturing the span of the arms of the 'U' aligned in parallel, and by placing the extending portion of the loop distally to the right, forming the short arm of the "Γ". Neobladder neck configuration was performed by suturing a tract of 2-5 cm longitudinally from the 12 o'clock position of the anastomosis. Then, the posterior plate was folded anteriorly, distal to proximally, roughly 5 cm right from the proximal edge of the posterior closure with the goal of creating two symmetrical segments.

Ureteral reimplantation After a careful isolation of the ureters avoiding iatrogenic blood supply damages, the ureteric stumps were sectioned and adequately spatulated. Bilateral ureteral reimplantation was then performed orthotopically and directly with no anti-reflux mechanisms on the lateral side of each anterior segment with mucosa-mucosa inverted sutures. In case of stentless procedure the anastomosis was performed directly while mono J ureteral catheters were employed in case of stent placement. The anterior plate was therefore closed by an "∧" -shaped suture. Both mono J stents were passed through the closing of the two anterior plates in the stent group.

Inclusion Criteria:

• Patients with diagnosed Bladder Cancer with clinical stage T1-T4N0-N1M0
• Patients amenable to radical cystectomy with eligible to orthotopic neobladder reconfiguration curative intent and FloRIN reconfiguration were included.

Exclusion Criteria:

• Presence of one or multiple tumor metastases at preoperative staging
• Histopathological confirmation of bladder tumor at the level of prostatic urethra; - Treatment without curative intent (cT4b, salvage or palliative cystectomies)
• Presence of urethral stricture