Robotic hepatectomy across IWATE difficulty levels: a single-center experience of the first 100 cases

This study describes our institutional experience with robotic hepatectomy, analyzes trends, and evaluates intraoperative and postoperative outcomes stratified by IWATE-defined procedural difficulty. Retrospective cohort study of the first 100 consecutive robotic hepatectomies performed by the abdominal transplant division at a high-volume center (2017–2025). Outcomes were compared across IWATE groups and between early (2017–2021) and late (2022–2025) cohorts. Logistic regression was used to examine the association between IWATE score and conversion to open surgery, 30-day complications, and major complications (Clavien–Dindo ≥ IIIa). Median age was 61 years (IQR 47–70), 52% were female, and 77% had malignant disease. 28% of resections were major. IWATE categories were low in 29%, intermediate 46%, advanced 7%, and expert 18%. Median operative time was 217 min (IQR 160–294), estimated blood loss was 150 mL (IQR 50–300), and length of stay was 3 days (IQR 2–4). Conversion to open surgery occurred in 22% with no emergent cases; 30-day complications occurred in 21%, major complications in 10%, readmission in 5% and 90-day mortality in 1%. Over time, expert cases and major hepatectomies increased without statistically significant differences in conversion or complication rates. Across IWATE groups, operative time, Pringle use, blood loss, transfusion, conversion, and length of stay increased with complexity (p < 0.001). Each 1-point increase in IWATE score independently increased the odds of conversion (adjusted OR 1.45, 95% CI 1.12–1.88) but not overall or major complications. Robotic hepatectomy was feasible across IWATE-defined difficulty levels while maintaining good perioperative outcomes. Increasing IWATE difficulty was associated with greater intraoperative complexity and a significantly higher likelihood of conversion to open surgery, although it was not independently associated with increased postoperative morbidity.