Impact of Endoscopic Ultrasound in Cholangiocarcinoma Staging: A Systematic Review and Meta-Analysis

BACKGROUND: Accurate staging is crucial for managing cholangiocarcinoma (CCA). Endoscopic ultrasound (EUS) with tissue acquisition (EUS-TA) may enhance cross-sectional imaging-based staging. However, the impact of EUS on CCA management decision-making is unclear. METHODS: Six electronic databases were searched through July 10, 2025 for studies on EUS-TA in staging CCA eligible for surgical resection or liver transplantation. The primary outcome was the pooled proportion of patients excluded from curative-intent surgery based on EUS-findings, which included newly detected findings and confirmation by EUS-TA of cross-sectional imaging findings. Secondary outcomes included the pooled incremental benefit of EUS (IBEUS) over cross-sectional imaging and EUS-specific adverse events. The IBEUS was defined as the proportion of patients with malignant lymph nodes identified by EUS-TA but not by cross-sectional imaging, relative to all patients who underwent cross-sectional imaging. RESULTS: Nine studies with 831 patients were included. The rate of exclusion from curative-intent surgery based on EUS findings was 10% overall (95% CI: 6%-18%; 9 studies), 7% for perihilar CCA (pCCA) (95% CI: 2%-19%; 5 studies), 10% for those planned for resection (95% CI: 4%-22%; 5 studies), and 8% for those planned for transplantation (95% CI: 3%-22%; 3 studies). The pooled IBEUS was 3% (95% CI: 1%-10%; 5 studies) overall, 4% (95% CI: 1%-17%; 3 studies) for pCCA1% (95% CI: 0%-3%; 2 studies) in patients intended for operative resection, and 7% (95% CI: 1%-26%; 2 studies) in those intended for transplantation. CONCLUSION: EUS may impact CCA staging and support treatment decisions.