22G Acquire vs. 20G Procore needle for endoscopic ultrasound-guided biopsy of pancreatic masses: a randomized study comparing histologic sample quantity and diagnostic accuracy

Background Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) has been suggested for obtaining high quality tissue samples from pancreatic tumors. We performed a multicenter randomized crossover trial comparing EUS-FNB with a 20G Procore needle vs. a 22G Acquire needle. The aims were to compare the quantity of targeted tissue (pancreas) and diagnostic accuracy for the two needles. Methods 60 patients admitted for EUS-FNB in three endoscopy units were included. One pass was performed consecutively with each needle, in a randomized order. Histologic material was studied in a blinded manner with respect to the needle. The primary end point was mean cumulative length of tissue core biopsies per needle pass. Results Final diagnosis was adenocarcinoma (n=46; 77%), neuroendocrine neoplasm (n=11; 18%), autoimmune pancreatitis (n=2), and mass-forming chronic pancreatitis (n=1). The mean cumulative length of tissue core biopsies per needle pass was significantly higher with the 22G Acquire needle at 11.4mm (95% confidence interval [CI] 9.0-13.8] vs. 5.4mm (95%CI 3.8-7.0) for the 20G Procore needle ( P <0.001), as was the mean surface area (3.5mm (2) [95%CI 2.7-4.3] vs. 1.8mm (2) [95%CI 1.2-2.3]; P <0.001). Diagnostic adequacy and accuracy were 100% and 87% with the 22G Acquire needle, and 82% and 67% with the 20G Procore needle ( P =0.001 and P =0.02, respectively). Conclusions EUS-guided biopsy of pancreatic masses with the 22G Acquire needle provided more tissue for histologic evaluation and better diagnostic accuracy than the 20G Procore needle.