# Contrast-enhanced vs. standard endoscopic ultrasound fine-needle aspiration for diagnosing malignant biliary tumors: Randomized controlled trial

## TL;DR

This study compares two endoscopic ultrasound methods for diagnosing malignant biliary tumors and finds similar accuracy between them.

## Contribution

The study provides the first randomized controlled trial comparing diagnostic accuracy of CH-EUS-FNA and standard EUS-FNA for malignant biliary tumors.

## Key findings

- CH-EUS-FNA and standard EUS-FNA showed similar diagnostic accuracy (83.3% vs. 82.1%) for malignant biliary tumors.
- Hyperenhancement with rapid washout was observed in 90.9% of cholangiocarcinoma cases using CH-EUS.
- Plastic stent placement and tumor location did not affect diagnostic outcomes.

## Abstract

Contrast-enhanced endoscopic ultrasound (CH-EUS) is superior to standard EUS for staging biliary duct tumors (BDTs), but its role in guiding EUS-guided fine needle aspiration (EUS-FNA) remains unclear. We compared diagnostic accuracy of CH-EUS-fine needle aspiration (CH-EUS-FNA) and standard EUS-FNA in patients with suspected malignant biliary stenosis.

A parallel randomized controlled trial was conducted in a tertiary medical center and included jaundiced patients with suspected malignant biliary stenosis on computed tomography. The patients were assigned randomly to EUS-FNA or CH-EUS-FNA groups. Final diagnosis was determined based on EUS-FNA, surgical specimen results, endoscopic retrograde cholangiopancreatography (ERCP), or 12-month follow-up.

Sixty-one patients were included in the study, 31 in the EUS-FNA group and 30 in the CH-EUS-FNA group. Mean age of participants was 74 ± 11.04 years and mean tumor size was 20.39 ± 9.17 mm, with 43 tumors in the distal bile duct. Final diagnoses were cholangiocarcinoma (37 cases), pancreatic ductal carcinoma (12 cases), other malignancies (3 cases), and benign lesion (9 cases). Diagnostic sensitivity, specificity, and accuracy were 83.3%, 100%, and 87.1% for EUS-FNA, and 82.1%, 100%, and 83.3% for CH-EUS-FNA. Plastic biliary stent placement and tumor location did not influence results. Hyperenhancement in the CH-EUS with rapid washout was observed in 90.9% of cholangiocarcinoma cases.

Standard EUS-FNA and CH-EUS-FNA demonstrated comparable diagnostic accuracy in evaluation of extrahepatic bile duct tumors, but with better slightly efficiency and inaccuracy indices than standard EUS-FNA.