LAUSR

Background/Aims To compare the diagnostic yield of 20-gauge forward-bevel core biopsy needle (CBN) and 22-gauge needle for endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) of solid pancreatic masses. Methods The use of 20-gauge CBN was prospectively evaluated for 50 patients who underwent EUS-FNA from June 2016 to December 2016. Data were compared with those obtained by a retrospective study of 50 consecutive patients who underwent EUS-FNA using standard 22-gauge needles between December 2016 and April 2017. At least two punctures were performed for each patient; the sample from the first pass was used for cytology with or without histology and that from the second pass was used for histology. Sample quantity was evaluated using the sample obtained from the second pass. Results There was no significant difference in the diagnostic accuracy rate between the first and second passes (20-gauge CBN: 96% [48/50]; standard 22-gauge needle: 88% [44/50]). Samples >10× power fields in length were obtained from 90% (43/48) and 60% (30/50) of patients using the 20-gauge CBN and standard 22-gauge needle, respectively (p=0.01). Technical failure occurred for two patients with the 20-gauge CBN. Conclusions Diagnostic accuracy of the 20-gauge CBN was comparable to that of the 22-gauge needle. However, two passes with the 20-gauge CBN yielded a correct diagnosis for 100% of patients when technically feasible. Moreover, the 20-gauge CBN yielded core tissue for 90% patients, which was a performance superior to that of the 22-gauge needle.