Initial Experience of Robot-Assisted Partial Nephrectomy Using Hinotori Surgical Robot System: Single Institutional Prospective Assessment of Perioperative Outcomes in 30 Cases

Introduction: Innovation of robotic surgery is still actively growing, and various novel robotic systems are in the process of development. The objective of this study was to assess the perioperative outcomes of robot-assisted partial nephrectomy (RAPN) using the hinotori surgical robot system, a recently developed robot-assisted surgical platform, for patients with small renal tumors. Methods: This study prospectively included a total of 30 consecutive patients who were found to have small renal tumors and subsequently underwent RAPN using hinotori between April and November 2022. Major perioperative outcomes in these 30 patients were comprehensively analyzed. Results: The median tumor size and R.E.N.A.L. nephrometry score in the 30 patients were 28 and 8 mm, respectively. Of these 30, 25 and 5 received RAPN by intra- and retroperitoneal approaches, respectively. RAPN could be completed in all 30 patients without conversion to nephrectomy or open surgery. The median operative time, time using hinotori, and warm ischemia time were 179, 106, and 13 minutes, respectively. No patient was found to have a positive surgical margin or experienced major perioperative complications, corresponding to Clavien-Dindo 3≤. Achievements of trifecta and margin, ischemia, and complications (MIC) outcomes in this series were 100% and 96.7%, respectively, and median changes in the estimated glomerular filtration rate 1 day and 1 month after RAPN were -20.9% and -11.7%, respectively. Conclusions: This is the first study focusing on RAPN using hinotori, which showed favorable perioperative outcomes, considering the findings of trifecta and MIC. Although it will be necessary to investigate the long-term effects of RAPN using hinotori on oncologic and functional outcomes, the present findings strongly suggest that the hinotori surgical robot system could be safely applied to RAPN for patients with small renal tumors.