Retrospective analysis of the utility of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in pancreatic masses, using a 22-gauge or 25-gauge needle system: a multicenter experience

Background and study aims: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is now performed routinely in many advanced endoscopy centers and has enhanced the ability to diagnose pancreatic masses. However, there is uncertainty about which needle size is optimal for EUS-FNA of pancreatic masses. We aimed to evaluate the performance of the 22-gauge and 25-gauge needles in obtaining cytologic diagnosis of pancreatic masses. Methods: All cases that were referred for EUS-FNA for pancreatic masses between February 2001 and June 2007 were reviewed, and patients who underwent EUS-FNA using the 22-gauge and 25-gauge needle system were identified. In patients who underwent surgery, operative histopathological findings were compared with the cytopathological findings from EUS-FNA. Results: A total of 842 patients with pancreatic masses detected on computed tomography (CT) and/or magnetic resonance imaging (MRI) and confirmed by EUS underwent EUS-FNA with the 22-gauge needle (n = 540) or the 25-gauge needle (n=302). Results of EUS-FNA cytology findings were compared with the gold standard of surgical histopathological findings or long-term clinical follow-up. The sensitivity, specificity, PPV, and NPV of FNA were respectively 84%, 100%, 100%, and 49% for the 22-gauge needle compared with 92%, 97%, 98%, and 89%, respectively for the 25-gauge needle. No complications were noted in the 25-gauge needle group, compared with pancreatitis in 2% of the 22-gauge needle group. Conclusions: This retrospective comparative study shows that EUS-FNA with a 25-gauge needle system is a safe and reliable method for tissue sampling in pancreatic masses. The system is more sensitive and has a higher NPV than the standard 22-gauge needle. Our study suggests that perhaps the smaller caliber FNA needle causes less trauma during EUS-FNA and hence less complications. Further studies including randomized trials are needed.