Introduction

Radical cystectomy with urinary diversion remains the gold standard treatment for patients with localized muscle-invasive bladder cancer and is often performed for those with bacillus Calmette-Guérin-refractory nonmuscle-invasive bladder cancer. The robotic-assisted approach (RARC) has promised improvements in open radical cystectomy (ORC) complication rates, though many purported benefits lack supporting evidence. Here we review the impact of RARC on urinary diversion for radical cystectomy.

Current Evidence: Extracorporeal Diversion

There have been 4 randomized trials to date which have evaluated RARC vs ORC (see Table). The first 2 published trials utilized exclusively extracorporeal urinary diversion (EUD), whereby an open incision was made for urinary reconstruction after the extirpative portion of the case was completed robotically.

Bochner et al from Memorial Sloan Kettering Cancer Center (MSKCC) published their single-center randomized trial of 118 patients in 2015, providing some of the earliest level 1 evidence comparing ORC and RARC with EUD.¹ There was significantly less operative time with the open approach (329 minutes ORC vs 456 minutes RARC, P < .001) but less blood loss robotically (676 mL ORC vs 515 mL RARC, P = .027). There were no differences in patient-reported quality of life outcomes at any time point, and while there was a decrease in wound complications (14% ORC vs 3% RARC, P = .041), there was no difference in overall complication rates. The authors concluded that RARC failed to demonstrate the large benefit promised by prior early reports.

RAZOR was a multicenter, randomized noninferiority trial comparing ORC vs RARC with EUD.² Among 302 randomized patients, there was no significant difference in 2-year progression-free survival (RARC 72.3% vs ORC 71.6%, HR 0.94, 95% CI 0.63-1.39) or adverse events (RARC 67% vs ORC 69%, P = .75), indicating noninferiority of RARC. The trial did demonstrate some advantages to RARC including decreased blood loss (300 vs 700 mL, P < .0001) and a small decrease in hospital length of stay (6 vs 7 days, P = .02). ORC was associated with significantly less operative time (428 vs 361 minutes, P = .0005).

While the RAZOR and MSKCC trials were some of the first to demonstrate comparable oncologic outcomes and noninferiority of RARC, a key limitation to both trials was the exclusive use of EUD for reconstruction instead of intracorporeal urinary diversion (IUD), which many have argued limits the potential benefits of the robotic approach. In this context, further trials were designed to evaluate RARC with IUD.

Current Evidence: Intracorporeal Diversion

In 2022, Mastroianni et al published their single-center randomized trial of 116 patients comparing RARC with IUD vs ORC.³ The only significant differences noted by the authors were decreased blood loss and transfusion rate for the robotic approach (EBL 401 mL vs 467 mL, P = .02; transfusion rate 22% vs 41%, P = .046) and a shorter operative time open (190 vs 313 minutes, P < .001). While limited by sample size and its single-center nature, this study provides evidence consistent with previous trials utilizing EUD.

The iROC trial was a multicenter randomized trial comparing RARC with IUD and ORC in 317 patients.⁴ For the primary outcome, days alive and out of the hospital at 90 days, RARC demonstrated an advantage of 2 days (82 vs 80 days, P = .01). RARC patients had a decreased length of hospital stay (7 vs 8 days, P = .05), readmission rate (21.8% vs 32.2%, P = .04), wound (5.6% vs 17.3%; difference [95% CI]: –11.7 [–18.6 to –4.6]), and thromboembolic (1.9% vs 8.3%, difference [95% CI]: –6.5 [–11.4 to –1.4]) complications. Among multiple other secondary outcomes, there were some marginal improvements noted for RARC, many of which disappeared by 12 weeks. The clinical significance of the highlighted differences in this trial remains uncertain. A limited number of high-volume centers have adopted IUD in virtually all RARC cases,⁵ but there remains significant variability in surgical approach (EUD vs IUD) and diversion type across the country, and there is no level 1 evidence directly comparing EUD and IUD.⁶

Long-term Functional Outcomes

Most of the randomized trials evaluating RARC are lacking in long-term follow-up data to evaluate functional outcomes including ureteroenteric anastomotic stricture (UEAS) rates. The MSKCC group demonstrated a 9.3% increased risk of UEAS in ORC patients (95% CI 1.5%-17%, P = .026) in their trial cohort.⁷ However, there are conflicting reports from other large retrospective series. Some have shown no difference in UEAS by surgical approach,⁸ while others have shown increased risk of UEAS with RARC with IUD compared to ORC.⁹ Whether RARC truly has an impact of UEAS rates remains unknown, and further research in this area is warranted.

Trends in Diversion Type

Some select centers have maintained high rates of continent diversion use over time (55% of all patients in some series¹), but most published series have demonstrated declining utilization over the past several years.¹⁰ This trend is concurrent with the increasing adoption of RARC and IUD. Intracorporeal ileal conduit creation is complex and time intensive with a significant learning curve, and intracorporeal orthotopic neobladder creation compounds this complexity.¹¹ While adoption of robotic surgery may contribute to stable or declining rates of continent diversion use, other long-standing factors including limited resident training, centralization of cystectomy care, technical complexity, and patient factors may also be mediating this trend.

Conclusions

Utilization of RARC is increasing rapidly despite limited evidence supporting its superiority over an open approach. Randomized trials have thus far failed to demonstrate the large benefits promised by RARC. This continued adoption mirrors the increased use of the robotic platform for radical prostatectomy and may reflect a national trend of decreasing trainee experience with complex open pelvic surgery.¹² Despite these technical advances, radical cystectomy remains a high-risk surgery, and while there is abundant interest in the promise of surgical robotics, the centralization of cystectomy care to high-volume centers with surgeons performing the procedure using their preferred technique may be more impactful on patient outcomes.¹³ As new technologies push the boundaries of surgical bladder cancer management,¹⁴ time will tell what interventions ultimately have an impact on our patients.