Robot-Assisted versus Laparoscopic Radical Nephrectomy for High-Complexity Renal Tumors: A Multidisciplinary Systematic Review and Meta-Analysis.

Background: Radical nephrectomy for high-complexity renal tumors, stage T2-T4, size ≥7 cm, and/or inferior vena cava (IVC) involvement, represents one of the most technically demanding procedures in urologic oncology. Robot-assisted radical nephrectomy (RARN) has expanded rapidly in adoption, yet its comparative benefit over laparoscopic radical nephrectomy (LRN) in the high-complexity subpopulation remains undefined. No systematic review has restricted analysis to T2-T4 disease or applied a multidisciplinary outcome framework spanning surgical, renal, infectious, and oncologic domains. Methods: Searches of PubMed/MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science, Scopus, and CINAHL retrieved comparative studies (randomized controlled trials, prospective and retrospective cohorts, case-control studies) reporting RARN versus LRN outcomes in adults with high-complexity renal tumors. Screening, data extraction, and risk-of-bias assessment were performed independently in duplicate. Pooling used DerSimonian-Laird random-effects meta-analysis. Heterogeneity was quantified using I² and 95% prediction intervals. Evidence certainty was graded with GRADE. A total of 22 studies encompassing 4,163 patients (RARN: 1,748; LRN: 2,415) met inclusion criteria. Results: RARN was associated with a significantly lower conversion rate to open surgery (odds ratio [OR] 0.38, 95% CI 0.21-0.68; I²=11%; moderate-certainty evidence), reduced estimated blood loss (mean difference [MD] -81.4 mL, 95% CI -112.3 to -50.5; I²=48%), lower transfusion rate (OR 0.54, 95% CI 0.35-0.84), and superior eGFR preservation (MD +3.2 mL/min/1.73 m², 95% CI 0.8-5.6). Operative time was longer in the RARN group (MD +22.7 min, 95% CI 9.3-36.1). No statistically significant differences emerged in overall complication rate, major complication rate, positive surgical margin rate, or recurrence-free survival; however, RARN was associated with a modestly shorter length of stay. Subgroup analysis demonstrated the greatest RARN advantage in IVC thrombus cases (Mayo level III-IV) and tumors ≥10 cm. Conclusions: Among adults undergoing radical nephrectomy for high-complexity renal tumors, RARN confers a meaningful reduction in conversion to open surgery, intraoperative blood loss, transfusion requirement, and acute renal functional loss compared with LRN, at the cost of modestly longer operative time. Evidence quality is moderate for the primary outcome and low-to-moderate for secondary endpoints, reflecting a predominantly observational evidence base. A dedicated randomized controlled trial in the T3-T4 and IVC thrombus subpopulation remains the priority for future research.