Abstract
Background/Objectives: This study aimed to evaluate and compare the perioperative outcomes of robot-assisted partial nephrectomy (RAPN) for complex renal tumors performed using the novel Japanese Hinotori Surgical Robot System (HSRS) and the established Da Vinci Surgical System (DVSS). Methods: Of 484 consecutive patients who underwent RAPN at our institution, 126 with complex renal tumors were included in the DVSS group, and 48 such patients were included in the HSRS group. Complex tumors in this series were defined by the presence of at least one of the following factors: cT1b, completely endophytic, hilar, cystic, or ipsilateral multiple tumors. Results: Following 1:2 propensity score matching, 74 and 37 patients were included in the DVSS and HSRS groups, respectively. Post-matching, most covariates' absolute standardized mean difference (SMD) was less than 0.1, indicating effective baseline imbalance correction. All RAPN procedures using HSRS were completed without conversion to open surgery, nephrectomy, or Clavien-Dindo ≥3 postoperative complications. No significant differences in major perioperative outcomes were observed between DVSS and HSRS, including operative time (178 vs. 186 min), console time (115 vs. 115 min; encompassing cockpit time for HSRS), warm ischemia time (15 vs. 15 min), and estimated blood loss (51 vs. 30 mL). Positive surgical margin rates (DVSS 1.4% vs. HSRS 5.4%) and Trifecta achievement rates (94.6% vs. 91.9%) were also comparable, with no significant differences. Conclusions: These findings suggest that, even in patients with complex renal tumors, RAPN performed using the HSRS can achieve perioperative outcomes comparable to those obtained with the established DVSS.