Objective: Although a large gauge needle can procure more tissue at endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), its advantage over smaller needles is unclear. This study compared flexible 19G and 25G needles for EUS-FNA of solid pancreatic masses.

Methods: This was a randomized trial of patients undergoing EUS-FNA of pancreatic masses using flexible 19G or 25G needle. Main outcome measure was to compare median number of passes for on-site diagnosis. Secondary measures were to compare specimen bloodiness, complications, technical failures, and histological core tissue procurement.

Results: One hundred patients were randomized to EUS-FNA using flexible 19G or 25G needle. Median of 1 pass was required to achieve on-site diagnosis of 96% and 92% (P = 0.68) in 19G and 25G cohorts. There was no significant difference in technical failure (0% vs 2%, P = 0.99) or adverse events (2% vs 0%, P = 0.99) between 19G and 25G cohorts. Although histological core tissue procurement was significantly better with flexible 19G needle (88% vs 44%, P < 0.001), specimens were bloodier (severe bloodiness, 36% vs 4%; P < 0.001).

Conclusions: As there is no significant difference in the performance of flexible 19G and 25G needles, needle choice for sampling pancreatic masses should be based on endoscopist preference and need for histology.