EUS-guided reverse bevel fine-needle biopsy sampling and open tip fine-needle aspiration in solid pancreatic lesions - a prospective, comparative study

Objectives: Different diagnostic entities can present as solid pancreatic lesions (SPL). This study aimed to explore the utility of endoscopic ultrasound-guided reverse bevel fine-needle biopsy sampling (EUS-FNB) in SPLs.Material and methods: In 2012-2015, consecutive patients with SPLs were prospectively included in a tertiary center setting and subjected to dual needle sampling with a 22 gauge reverse bevel biopsy needle and a conventional 25 gauge open tip aspiration needle (EUS-FNA). The outcome measures were the diagnostic accuracy of sampling, calculated for each modality separately and for the modalities combined (EUS-FNA+FNB), and the adverse event rate related to sampling.Results: In 68 unique study subjects, the most common diagnostic entities were pancreatic neuroendocrine tumor, PNET, (34%), pancreatic ductal adenocarcinoma, PDAC, (32%), pancreatitis (15%) and metastasis (6%). The overall diagnostic accuracy of EUS-FNB was not significantly different from that of EUS-FNA, (69% vs. 78%, p=.31). EUS-FNA+FNB, compared with EUS-FNA alone, had a higher sensitivity for tumors other than PDAC (89% vs. 69%, p=.02) but not for PDACs (95% vs. 85%, p=.5). No adverse event was recorded after the study dual-needle sampling procedures.Conclusions: Endoscopic ultrasound-guided tissue acquisition performed with a 22 gauge reverse bevel biopsy needle is safe but not superior to conventional fine-needle aspiration performed with a 25 gauge open tip needle in diagnosing solid pancreatic lesions. However, the performance of both these modalities may facilitate the diagnostic work-up in selected patients, such as cases suspicious for pancreatic neuroendocrine tumors and metastases. NCT02360839.