BackgroundRadical cystectomy (RC) with urinary diversion is the recommended treatment for selected cases of non-metastatic high-risk non-muscle-invasive and muscle-invasive bladder cancer. It remains unknown whether robot-assisted laparoscopic cystectomy (RARC) offers any advantage in terms of safety compared to open cystectomy (ORC) in an Enhanced Recovery After Surgery (ERAS) setup. Blinded randomised controlled trials (RCTs) between RARC versus ORC have never been conducted in cystectomy patients. We will investigate the feasibility of conducting a double-blinded RCT comparing ORC with RARC with intra-corporal ileal conduit (iRARC) in an ERAS setup.MethodsThis is a single-centre, double-blinded, randomised (1:1) clinical feasibility study for patients with non-metastatic high-risk non-muscle-invasive or muscle-invasive bladder cancer scheduled for cystectomy. All participants are recruited from Rigshospitalet, Denmark. The planned sample size is 50 participants to investigate whether blinding of the surgical technique is feasible. Participants and postoperative caring physicians and nurses are blinded using a pre-study designed abdominal dressing and blinding of the patient’s electronic health record. Study endpoints are assessed 90 days postoperatively. The primary aim is to study the frequency and pattern of unplanned unblinding after surgery and the number of participants who cannot guess the surgical technique at the day of discharge. Eleven secondary endpoints are assessed: length of stay, days alive and out of hospital, in-hospital complication rate, 30-day complication rate, 90-day complication rate, readmission rate, quality of life, blood loss, pain, rate of moderate/severe post-anaesthesia care unit (PACU) complications, and delirium. Participants are managed in an ERAS setup in both arms of the trial.DiscussionWe report on the design and objectives of a novel experimental feasibility study investigating whether blinding of the surgical technique in cystectomy patients is possible. This information is essential for the design of future blinded trials comparing ORC to RARC. There is a continued need to compare RARC and ORC in terms of both efficacy, safety, and oncological outcomes. Estimated end of study is March 2021.Trial registrationClinicalTrials.gov ID: NCT03977831. Registered on the 6th of June 2019.