Exploratory Clinical and Cost Evaluation of Robot-Assisted Adrenalectomy Using the hinotori™ Surgical Robotic System: A Single-Center Retrospective Study

Purpose: Although the hinotori™ surgical robotic system is Japan's first domestically developed platform, evidence regarding its clinical feasibility remains limited. Because adrenalectomy is a standardized minimally invasive procedure with well-defined perioperative outcomes, it provides an appropriate model for evaluating newly introduced robotic platforms. We evaluated the clinical outcomes and medical costs of robot-assisted adrenalectomy (RAAD) using the hinotori™ system (H-RAAD) and compared them retrospectively with those of da Vinci Xi™-assisted RAAD (D-RAAD). Materials and methods: We retrospectively examined patients who underwent RAAD at Nippon Medical School Hospital between September 2023 and May 2025. Baseline demographic characteristics, perioperative variables, postoperative outcomes, pathological findings, and medical costs extracted from the Diagnosis Procedure Combination (DPC) database were evaluated. Results: We evaluated 12 patients (H-RAAD, n = 5; D-RAAD, n = 7). Baseline characteristics were comparable between the groups, although the median tumor diameter was numerically smaller in the H-RAAD group. The median anesthesia, operative, and console times in the H-RAAD group were 264 (253-307, U = 10.0, p = 0.22), 189 (156-264, U = 10.0, p = 0.29), and 108 (71-180, U = 14.0, p = 0.57) minutes, respectively, comparable with those in the D-RAAD group. Total medical costs per case were similar between the D‐RAAD ($6,333.1) and H‐RAAD ($6,398.4) groups (U = 23.0, p = 0.34). Conclusions: In this small cohort, H-RAAD was completed safely without conversion or major complications, demonstrating perioperative outcomes similar to those of D-RAAD. Although individual cost components varied, total reimbursed medical costs under the DPC system were comparable. Given the limited sample size and exclusion of robotic system capital and maintenance costs, these findings remain exploratory.