Nutritional–Inflammatory Recovery After Metal versus Plastic Biliary Stenting in Elderly Cholangiocarcinoma: A Prospective Observational Cohort Study

Chen Li, Nana Zhang, Huhu Ren Department of Interventional Therapy, Honghui Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, 710054, People’s Republic of ChinaCorrespondence: Huhu Ren, Department of Interventional Therapy, Honghui Hospital, Xi’an Jiaotong University, 666 North Jianyuan 2nd Road, Economic and Technological Development Zone, Xi’an, Shaanxi, 710054, People’s Republic of China, Email [email protected]: Malignant biliary obstruction (MBO) in elderly cholangiocarcinoma is frequently accompanied by systemic inflammation and impaired immune–nutritional reserve. We compared stent durability and early nutrition-inflammation recovery after self-expandable metal stents (SEMS) versus plastic stents.Methods: We conducted a single‑center prospective observational cohort of consecutive patients aged ≥ 65 years undergoing first‑time biliary stenting (2019– 2024; N=188; SEMS n=109; plastic stent n=79). The primary endpoint was time to recurrent biliary obstruction (TRBO; TOKYO criteria), with death treated as a competing event. Confounding was addressed using propensity score overlap weighting. Competing‑risk outcomes were analyzed with Fine–Gray regression overall survival (OS) with weighted Cox models, longitudinal GNRI, PNI, NLR, and log(SII) trajectories with mixed‑effects models. Prognostic associations were evaluated using a prespecified 30‑day landmark analysis.Results: At 6 months, the overlap‑weighted cumulative incidence of TRBO was 35.6% with SEMS versus 52.9% with plastic (sHR 0.64, 95% CI 0.44– 0.93). SEMS was associated with fewer biliary reinterventions (any intervention 44.1% vs 68.2%; sHR 0.58, 95% CI 0.41– 0.82). From baseline to day ~30, SEMS recipients had greater recovery in GNRI (mean difference +1.9; 95% CI 0.4– 3.4) and PNI (+1.8; 95% CI 0.5– 3.1) and a larger reduction in log(SII) (− 0.10; 95% CI − 0.19 to − 0.01). In the landmark cohort (n=153), each 3‑point increase in ΔPNI was associated with lower mortality (HR 0.86, 95% CI 0.78– 0.95), while higher day‑30 SII predicted higher mortality (per doubling HR 1.22, 95% CI 1.05– 1.42). OS and 30‑day adverse events did not differ significantly.Conclusion: In elderly cholangiocarcinoma with MBO, SEMS was associated with lower TRBO and fewer reinterventions, and with more favorable early nutrition–inflammation recovery. Early PNI improvement and residual inflammatory burden at ~30 days provided prognostic information, supporting integrated post‑drainage nutrition–inflammation monitoring.Keywords: cholangiocarcinoma, malignant biliary obstruction, recurrent biliary obstruction, geriatric nutritional risk index, systemic immune-inflammation index