Development of a novel difficulty scoring system for laparoscopic liver resection procedure in patients with intrahepatic duct stones

BACKGROUND For intrahepatic duct (IHD) stones, laparoscopic liver resection (LLR) is currently a reliable treatment. However, the current LLR difficulty scoring system (DSS) is only available for patients with hepatocellular carcinoma. AIM To explore the development of a DSS for IHD stone patients with LLR and the validation of its reliability. METHODS We used clinical data from 80 patients who received LLR for IHD stones. Forty-six of these patients were used in multiple linear regression to construct a scoring system. Another 34 patients from different centers were used as external validation. The completeness of our DSS was then evaluated in patients with varying degrees of surgical difficulty based on documented surgical outcomes in the study group of patients. RESULTS The following five predictors were ultimately included and scored by calculating the weighted contribution of each factor to the prediction of operative time in the training cohort: Location of stones, number of stones ≥ 3, stones located in the bile ducts of several grades, previous biliary surgery less than twice, distal bile duct atrophy. Subsequently, the data set was validated using a DSS developed from the variables. The following variables were identified as statistically significant in external validation: Operative time, blood loss, intraoperative transfusion, postoperative alanine aminotransferase, and Clavien-Dindo grading ≥ 3. These variables demonstrated statistically significant differences in patients with three or more grades. CONCLUSION Patients with IHD stones have varying degrees of surgical difficulty, and the newly developed DSS can be validated with external data to effectively predict risks and complications after LLR surgery.