Comparison of the Diagnostic Performance of Newly Designed 21-Gauge and Standard 22-Gauge Aspiration Needles in Patients with Solid Pancreatic Masses

Background Although endoscopic ultrasound-guided fine needle aspiration (EUS–FNA) has been widely used for the diagnosis of pancreatic tumors, the ability to obtain adequate pancreatic tumor tissue needs to be improved. Aims This study was performed to compare a newly designed 21-gauge needle (EUS Sonopsy CY; Hakko Medical, Nagano, Japan) and a standard 22-gauge needle for tissue sampling of solid pancreatic masses. Methods Consecutive patients with solid pancreatic masses who underwent EUS–FNA with either the EUS Sonopsy CY or the 22-gauge needle from June 2014 to December 2016 were enrolled. The primary outcome was comparison of the diagnostic yield of the FNA samples. The secondary outcomes were comparison of technical success, diagnostic ability for malignancy, and complications. Results A total of 93 patients (40.9% female; mean age, 70.1 years) underwent EUS–FNA with the EUS Sonopsy CY ( n = 47) or the standard 22-gauge needle ( n = 46). The technical success rate was 100% in both groups, and the overall diagnostic accuracy for malignancy was similar between the groups (100% in the EUS Sonopsy CY group vs. 95.7% in the 22-gauge needle group, P = 0.242). Nevertheless, the EUS Sonopsy CY resulted in significantly higher scores for cellularity ( P = 0.006) and lower scores for blood contamination ( P