From difficulty score to clinical outcome: Evaluating IWATE-criteria correlation with postoperative complications and revision surgery in anatomical liver resection

Backgrounds/Aims: Minimally invasive hepatobiliary surgery has advanced considerably, with laparoscopic liver resection now widely adopted. The IWATE difficulty score is commonly used to classify the technical complexity of laparoscopic resections; however, its ability to predict postoperative morbidity across different surgical approaches remains uncertain. This study aimed to evaluate the association between the IWATE score and postoperative complications and revision surgery following anatomical liver resection (ALR), irrespective of surgical approach. Methods: We conducted a retrospective analysis of 168 patients who underwent ALR between 2014 and 2018 at a tertiary hepatobiliary center. Resections were stratified according to the IWATE score. For open procedures, the score was modified by subtracting one point to approximate the hand-assisted category, as an exploratory adjustment. Perioperative outcomes, including overall postoperative complications and revision surgery, were analyzed using univariate and multivariable logistic regression. Results: = 0.004). Laparoscopic resections were associated with reduced blood loss, lower transfusion rates, and improved postoperative recovery. Receiver operating characteristic analysis demonstrated good predictive performance of the IWATE score (area under the curve 0.87 and 0.79). Conclusions: The IWATE score is independently associated with postoperative morbidity and revision surgery following ALR and may serve as a universal preoperative risk stratification tool across surgical approaches. Prospective validation is warranted.