The purpose of the study to compare two established methods of radical cystectomy (RC) in patients with bladder cancer. The participants will be treated under conditions in alignment with up-to-date guidelines and care. We wish to investigate whether it is feasible to compare the two methods under conditions of the highest methodological quality.

Radical cystectomy (RC) is a comprehensive surgery including pelvic lymph node dissection and urinary diversion. The surgery is originally performed as an open procedure (ORC) but with advances in technology the procedure is now also offered as a robot-assisted laparoscopic procedure (RARC). It remains questionable if RARC is superior to ORC in terms of surgical outcomes.

Several studies have described outcomes following RARC of which most are comparative studies with only five studies being randomized controlled trials (RCTs). Overall, significant differences in operating room time, estimated blood loss, time to flatus and bowel movement as well as use of morphine sulfate equivalents in favor of RARC has been demonstrated with the exception of operating room time. However, no studies have demonstrated a significant reduction in risk of 30- or 90-day complication rates between ORC and RARC. The RCTs have not been blinded, and therefore may be subject to bias in terms of expectations from patients and care providers. Also, in the already conducted RCTs of ORC versus RARC the urinary diversion has been done extracorporally. Today, it is possible to conduct the whole procedure of RARC intracorporally (iRARC), potentially reducing the surgical stress further. Lastly, the previously conducted RCTs have not consequently been managed under an Enhanced Recovery After Surgery (ERAS) setup. Currently, a multicenter study comparing ORC with RARC is recruiting in the United Kingdom in which the patients are treated with iRARC and under an ERAS setup. The present study will compare the two methods blinded for the participants and all health care providers involved in the postoperative care from the time the patient exits the operating room (OR). Blinded studies in surgery are rare but in gastrointestinal surgery, a blinded study of open versus laparoscopic colonic resection has demonstrated to be feasible and thus we believe that such study must be feasible in an RC setting.

Participants will be randomized 1:1 to either ORC or RARC. Blinding: The study is blinded for the patient and for the group of nurses and doctors that will be responsible for the postoperative care. The postoperative care will be managed by members of the bladder cancer team other than the operating surgeon, and OR staff will not be involved in the postoperative care. The abdominal wound will be bandaged to hide the wounds from both an open and laparoscopic procedure. The blinding will be maintained until discharge from hospital.

Inclusion Criteria:

• age> 18
• non-metastatic disease
• fit for both ORC and RARC
• Patient-selected urinary diversion: ileal conduit

Exclusion Criteria:

• if not able to speak/understand Danish
• not able to cooperate for fully informed consent
• need for extensive concomitant surgery (i.e. nephroureterectomy)
• prior down staging chemotherapy (prior neoadjuvant chemotherapy accepted)
• prior radiation therapy
• prior major extensive abdominal or pelvic surgery
• prior peritonitis
• conditions contraindicating extended Trendelenburg's position