Abstract
To investigate the predictive value of sarcopenia and systemic immune-inflammatory index (SII) for short-term complications and long-term outcome after radical surgery in patients with distal cholangiocarcinoma. Retrospective collection of clinical data from patients who underwent radical surgery for distal cholangiocarcinoma was conducted. The patients were then divided into two groups: sarcopenia group and normal group, based on their skeletal muscle index (SMI). Logistic regression was employed to analyze the risk factors for major postoperative complications (Clavien-Dindo ≥ grade III). Additionally, Cox proportional hazards model was used to identify independent risk factors for overall survival (OS) and disease-free survival (DFS). Also, a nomogram model was developed for predicting OS and DFS at 1 and 3 years after surgery. A total of 111 patients were finally included in the study based on the inclusion-exclusion criteria. Multifactorial logistic regression analysis revealed that sarcopenia was an independent risk factor for major postoperative complications in distal cholangiocarcinoma patients (P < 0.001). Furthermore, multifactorial Cox regression analysis indicated that sarcopenia and high SII levels were independent risk factors affecting OS and DFS (P < 0.05). A nomogram model, incorporating preoperative sarcopenia, SII, and other factors, exhibited strong predictive efficacy, calibration, and clinical utility for OS and DFS after radical surgery. Sarcopenia and high SII levels are associated with poor prognosis and are independent risk factors for OS and DFS in patients undergoing radical surgery for distal cholangiocarcinoma. Sarcopenia and SII are convenient, inexpensive, and reliable markers for improving postoperative prognosis and new therapeutic strategies for patients with distal cholangiocarcinoma. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1038/s41598-025-30485-5.