Experience with hinotori^TM, the Japan-made Surgical Robotic System, in the Initial 94 Cases of Colorectal Cancer

Abstract

Objectives: Robot-assisted surgery has rapidly expanded worldwide. The hinotori™ Surgical System (hinotori), the first domestically developed robotic platform in Japan, has recently been introduced in colorectal surgery. This study aimed to evaluate the clinical outcomes of colorectal procedures performed using the hinotori.

Methods: A single-center retrospective observational study was conducted on consecutive patients who underwent robot-assisted colorectal surgery with the hinotori at Kyoto University Hospital between August 2023 and November 2025. Patient demographics, operative details, and short-term outcomes were analyzed separately for colon and rectal cancer.

Results: A total of 94 patients were included: 53 with colon cancer and 41 with rectal cancer. In the colon cancer group, the median operative time was 255 minutes, and one patient (1.9%) developed a Clavien-Dindo grade II complication; no grade ≥III events occurred. In the rectal cancer group, the median operative time was 327 minutes, and one patient (2.4%) experienced a grade II complication; no grade ≥III complications occurred. No conversions to open surgery and no reoperations within 30 days were observed. The median postoperative hospital stay was 10 days for colon cancer and 12 days for rectal cancer.

Conclusion: Robot-assisted colorectal surgery using the hinotori was safe and feasible. This largest case series to date provides data supporting its feasibility and safety.