The difference in histological yield between 19G EUS-FNA and EUS-fine-needle biopsy needles

Background and objective: EUS-guided fine-needle biopsy (EUS-FNB) with acquisition of tissue core is possible with the use of 19G fine-needle aspiration (FNA) and dedicated biopsy needles. Published data of direct comparisons between biopsy needles are more limited compared to the abundant data comparing EUS-FNA with EUS-FNB. We performed a retrospective study to determine the difference in histologic yield between 19G FNA needle and EUS-FNB needles in patients with solid masses.

Materials and methods: Consecutive patients who underwent EUS-FNB of solid masses from January 2014 to July 2018 were identified from a database. The difference in histologic yield between needles was analyzed.

Results: A total of 159 patients underwent 179 EUS-FNB procedures (median of 2 needle passes [range: 1-4]). The use of 19G FNA, 19G, 20G, and 22G FNB needles allowed acquisition of a histologic core in 67.4% (29/43), 72.5% (29/40), 82.1% (46/56), and 75.9% (22/29), respectively (P = 0.368). A significant difference in the yield of histologic core was detected when 19G FNA needle was compared with 22G Acquire™ FNB needle (67.4% [29/43] vs. 94.1% [16/17], P = 0.032). The presence of histologic core was significantly associated with a positive diagnosis (95.6% vs. 30.2%, P < 0.0001).

Conclusion: EUS-FNB with acquisition of histologic core improved the diagnostic yield. Dedicated FNB needles appeared to achieve a higher yield of histologic core compared to 19G FNA needles.