Contrast-Enhanced Harmonic Endoscopic Ultrasound-Guided Puncture for the Patients with Pancreatic Masses

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is useful for the diagnosis of pancreatic masses. According to three meta-analyses, the sensitivity, specificity, and accuracy of EUS-FNA are 84-92%, 96-98%, and 86-91%, respectively. However, the occurrence of false-negative and false-positive results indicates that the diagnostic performance of EUS-FNA needs to be improved. Contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) is used for the characterization of pancreatic masses and can be applied to improve the performance of EUS-FNA. When CH-EUS is used to evaluate intratumor blood flow, an avascular area inside the pancreatic mass that is considered to be fibrosis is often detected. This area can be avoided by performing EUS-FNA under CH-EUS guidance. In this review, we summarize the data on contrast-enhanced harmonic endoscopic ultrasound-guided fine-needle aspiration (CH-EUS-FNA), which suggest that its benefit is still a matter of debate. Of eight studies analyzed, only one showed that CH-EUS improved the sensitivity of EUS-FNA. The future challenge is to determine under what circumstances CH-EUS-FNA is useful.