Comparison of 20-gauge Procore® and 22-gauge Acquire® needles for EUS-FNB of solid pancreatic masses: an observational study.

Background and Aims: Endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) has been proposed to obtain high-quality tissue samples for pancreatic tumors. We performed an observational study to compare EUS-FNB with a 20-gauge Procore® needle versus a 22-gauge Acquire® needle. Our primary endpoint was the quantity of the obtained tissue, as defined by the mean cumulative length of tissue core biopsies per needle pass. Methods: Sixty-eight EUS-FNB were consecutively performed on patients with a pancreatic mass. The choice of needle depended on availability at the time of admission: 34 punctures were performed with each needle. Histological material was studied in a blinded manner with respect to the needle, and the cumulative length of tissue core biopsies per needle pass was determined. Intraobserver and interobserver variability of this criterion was then evaluated. Results: There were no between-group differences. Histological diagnosis was achieved and core biopsy specimens were obtained in 28 out of 34 patients (82%) in the 20-gauge Procore® group and in 33 out of 34 patients (97%) in the 22-gauge Acquire® group (p = .1). The mean cumulative length of tissue core biopsies per needle pass was significantly higher with the 22-gauge Acquire® needle with 8.2 ± 4.2 mm versus 4.2 ± 3.8 mm for the 20-gauge Procore® needle (p < .01). No intra and inter-observer variability of this criterion was observed. Conclusions: Our results suggest significant differences, with a mean cumulative length of tissue core biopsies per needle pass significantly higher with the 22-gauge Acquire® needle. This simple criterion seems reliable and reproducible.