The prospective randomized, controlled trial of endoscopic ultrasound-guided fine-needle aspiration using 22G and 19G aspiration needles for solid pancreatic or peripancreatic masses.

Objectives: A large-caliber needle such as a 19-gauge needle may help overcome the limitations of a 22-gauge needle by acquiring a larger amount of tissue sample. However, there has been no well-designed comparative study for endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with a 19-gauge aspiration needle. We conducted this study to compare the diagnostic accuracy of EUS-FNA using a 19-gauge aspiration needle with that using a 22-gauge aspiration needle in patients with solid pancreatic/peripancreatic mass.

Methods: From March 2007 to April 2008, a total of 117 patients (60 in a 19-gauge needle group and 57 in a 22-gauge needle group) with solid pancreatic/peripancreatic mass were included. EUS-FNA was performed using the standard technique without an on-site cytopathologist. A single, blinded cytopathologist retrospectively evaluated each set of slides.

Results: The diagnostic accuracy by intention-to-treat analysis was not significantly different (19G: 86.7% vs. 22G: 78.9%, P=0.268). However, the diagnostic accuracy by per-protocol analysis, excluding technical failures, was significantly higher in the 19-gauge needle group (94.5% vs. 78.9%, P=0.015). In the treatment-received group that included crossover cases, although the diagnostic accuracy in all cases was not significantly different (86.1% vs. 76.9%, P=0.164), that of body/tail lesion (95.0% vs. 76.7%, P=0.031) and technically successful cases (93.9% vs. 78.1%, P=0.006) were significantly higher in the 19-gauge needle group. On sample quality analysis, the amount of cellular material obtained was significantly higher in the 19-gauge needle group (P=0.033).

Conclusions: EUS-FNA with a 19-gauge aspiration needle may be a valuable method for the diagnosis of pancreatic/peripancreatic masses when an on-site cytopathologist is not available.