Prospective Comparison of Diagnostic Accuracy Between Contrast-enhanced Harmonic and Conventional EUS-guided Fine-needle Biopsy in Solid Pancreatic Lesions

Endoscopic ultrasonography (EUS)-guided fine-needle aspiration/biopsy (FNA/B) is used to collect biopsy samples from many organs throughout the digestive tract and is useful in diagnosing solid pancreatic lesions (SPLs). The reported diagnostic accuracy of EUS-FNA for SPLs is 85-89.4%, the sensitivity is 82-94.7%, and the specificity is 100%. One randomized controlled trial reported that the fanning technique of FNA was superior to the standard approach because fewer passes were required to establish the diagnosis. However, in many cases, like SPLs with the presence of fibrosis and necrosis background, four or more needle passes are still needed to obtain sufficient biopsy samples. There is a potential risk of tumor seeding associated with multiple needle punctures. Therefore, it is important to minimize the number of needle passes.

Contrast-enhanced harmonic EUS (CEH-EUS) using sonazoid (Daiichi-Sankyo, Tokyo, Japan) is useful to visualize parenchymal perfusion in the pancreas and characterize of SPLs. Because the necrotic or fibrotic area within the SPLs were appeared as non-enhanced area, CEH-EUS could help us to avoid puncture the non-enhancing area hence increased the diagnostic accuracy. Katana et al. reported that conventional EUS-FNA has lower sensitivity (72.9%) for pancreatic adenocarcinoma with non-enhanced areas compared to with enhanced areas (94.3%) on CEH-EUS. Therefore, it would be difficult to obtain sufficient biopsy samples through unenhanced areas of SPLs.