Traditional radical cystectomy (RC) is performed transabdominal. However, it often has high postoperative complications. There have been studies on extraperitoneal approach to reduce postoperative complications. Investigators divided participants underwent robot-assisted radical cystectomy into two groups (1:1) . One group of participants transabdominal, the other group extraperitoneal. The incidence of complications and PFS/OS at 3, and 5 years were compared.

Bladder cancer is highly prevalent worldwide and approximately 75% of these are non-muscle invasive bladder cancer (NMIBC). For high-risk NMIBC and MIBC, radical cystectomy (RC) is also the best treatment option.

The traditional transperitoneal laparoscopic radical cystectomy prolapse of abdominal organs into the pelvic cavity can lead to angulation of the intestinal tract, causing obstruction. Some studies have demonstrated that the extraperitoneal route can effectively reduce these complications Currently, robot-assisted surgery technology is widely utilized in urology. Studies have demonstrated that robot-assisted total extraperitoneal cystectomy and urinary diversion are less likely to disrupt abdominal organs, particularly the intestines. Identifying and locating membrane structures and layers with anatomical significance is crucial for navigating the correct anatomic space during the operation. The using of 3D laparoscopy or a robot-assisted extraperitoneal radical cystectomy aligns more closely with the 3D membrane anatomic concept. Furthermore, for younger patients,robot-assisted extraperitoneal radical cystectomy is more favorable for preserving reproductive function. For elderly patients, it is considered more safer.

Consequently, we aim to investigate whether robot-assisted extraperitoneal radical cystectomy is more advantageous for patients with MIBC or high-risk NMIBC.

Inclusion Criteria:

1. Researchers evaluated patients with muscle invasive bladder cancer or high-risk non-muscular invasive bladder cancer who needed radical cystectomy.
2. Willing to accept the operation and meet the surgical index: a) Absolute count of neutrophils≥1.5x109/L; b) Platelets≥100×109/L; c) Hemoglobin≥90g/L; d) International standardized ratio or activationPartial thrombin time≤1.5 Upper limit of normal value (ULN); e) calculated creatinine clearance rate≥1 ml/s; f) Total serum bilirubin≤1.5×ULN; g) AST, ALT and alkaline phosphatase≤2.5×ULN; h) Cardiopulmonary function indicates that it can tolerate major abdominal surgery;
3. None of the pastHistory of abdominal surgery;
4. 18 to 75 years old;
5. ECOG physical state 0 or 1;
6. voluntarily participate in this experiment, be able to provide a written version of the informed consent, and be able to understand and agree to comply with the requirements of this study and the evaluation schedule;

Exclusion Criteria:

1. Patients who refuse to receive radical cystectomy
2. Researchers evaluate patients who are unable to tolerate radical cystectomy;
3. There is a abdominal history of surgery;
4. Have had a large-scale operation or major trauma within 28 days before joining the group;
5. Have been vaccinated with live vaccine within 28 days before joining the group;
6. Severe chronic or active infection that requires systemic anti-bacterial, antifungal or antiviral treatment within 14 days before joining the group;
7. Participating in the rest of the clinical research.