Endoscopic ultrasound-guided fine needle aspiration with 22- and 25-gauge needles in solid pancreatic masses: a prospective comparative study with randomisation of needle sequence.

Background: The difference in the diagnostic accuracy of 22- versus 25-gauge needles in EUS-FNA is not clear.

Objective: To compare the rates of technical success, diagnostic accuracy and complications of EUS-FNA performed with 22-gauge and 25-gauge needles on the same solid pancreatic mass.

Methods: All patients with solid pancreatic masses evaluated from September 2007 to December 2008 were enrolled and underwent EUS-FNA with both 22- and 25-gauge needles with randomisation of needle sequence. The accuracy of the EUS-FNA was determined by comparing the cytological results with the final surgical pathological diagnoses or with the results of a clinical follow-up. A cytological score with different qualitative parameters was created, and a comparison between these parameters was carried out for each needle.

Results: Fifty patients with 50 pancreatic masses were recruited. Technical success was 100% and no complications occurred. Diagnostic accuracy was 94% and 86% for the 25- and 22-gauge needles, respectively. Analysis of the cytological score showed a tendency towards the 25-gauge needle, although the difference was not statistically significant.

Conclusions: EUS-FNA performed with 22- or 25-gauge needles had the same diagnostic accuracy. Our study results confirm a significant trend towards a better cytological diagnosis for the 25-gauge needle.