Abstract
Completely endophytic renal tumors (CERTs), which are entirely confined within the renal parenchyma, present substantial technical challenges during nephron-sparing surgery. We conducted a systematic review and meta-analysis to compare robot-assisted partial nephrectomy (RAPN) with laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN) specifically for CERTs. PubMed/MEDLINE, Embase, Web of Science, and the Cochrane Library were searched through August 24, 2026. Eligible comparative studies directly evaluated RAPN versus LPN and/or OPN. Continuous outcomes were summarized using mean differences (MDs) and binary outcomes using risk ratios (RRs), with 95% confidence intervals (CIs). RAPN-LPN and RAPN-OPN comparisons were analyzed separately. Study quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS), and the protocol was registered in PROSPERO (CRD420261488778). Seven studies involving 896 patients were included, of whom 430 underwent RAPN and 466 underwent LPN or OPN. No statistically significant difference in operative time was detected between RAPN and either LPN or OPN. Estimated blood loss also did not differ significantly between RAPN and LPN (MD - 14.92 mL, 95% CI - 48.82 to 18.98; P = 0.39) or OPN (MD - 85.62 mL, 95% CI - 176.01 to 4.78; P = 0.06). RAPN was associated with a shorter hospital stay than OPN (MD - 1.64 days, 95% CI - 2.29 to - 0.98; P < 0.00001), whereas no significant difference was observed versus LPN. The lower transfusion risk with RAPN versus OPN was of borderline significance (RR 0.39, 95% CI 0.16-0.99; P = 0.05). No statistically significant differences were detected in conversion to radical nephrectomy, major complications, positive surgical margins, or 1-year postoperative eGFR. Ischemia-related outcomes were reported descriptively because operative ischemia strategies differed across studies. Overall, RAPN showed selected perioperative differences mainly in comparison with OPN, whereas most outcomes did not differ significantly from LPN. These findings should be interpreted cautiously because the evidence was based on a small number of predominantly observational studies with substantial heterogeneity for several outcomes.