Clinical Utility of Endoscopic Ultrasound-Guided Fine Needle Aspiration in Pancreatic Masses Using a 25-Gauge Needle System: A Multicenter Experience

Abstract

Background and Aims: 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 most optimal for EUS-FNA of pancreatic masses. All of the early published data on this topic is based on the use of 22-gauge or 19-gauge EUS-FNA needles. It is postulated that a smaller caliber needle might provide more accurate results and have less complications. We aimed to evaluate our experience in diagnosing pancreatic masses with EUS-FNA using a 25-gauge disposable needle system. Methods: All patients referred for EUS-FNA for pancreatic masses between Feb 2001 and Nov 2007 at three advanced endoscopy centers were reviewed and patients who underwent EUS-FNA using the 25-gauge needle system (EchoTip, Cook Endoscopy, Winton-Salem, NC) were identified. In this IRB exempt study data related to patient demographics, clinical findings, long term follow-up and pathological findings were recorded. In patients who underwent surgery, operative histopathology was compared with the cytopathology from EUS-FNA. Results: A total of 288 patients (mean age 65y, age range 18-91y; 150 M, 138 F) with pancreatic masses detected on CT and/or MRI and confirmed by EUS underwent EUS-FNA with the 25-gauge needle. Adequate samples were obtained in 94% (271/288) of the patients. Pancreatic malignancy was diagnosed on cytopathology in 56% (161/288) and no malignancy was identified in 38% (110/288) of the patients. EUS-FNA sample was inconclusive in 6% (17/28). No complications were reported in our study cohort. Of patients with pancreatic malignancy, 89% (144/161) had adenocarcinoma, while 11% (17/161) had other malignancies. Surgical pathology was available and compared to the EUS-FNA cytopathology in 26 patients. Inconclusive results were considered negative for comparison. There were no false-positive results and 3 false-negative FNA results (1 negative, 2 inconclusive). Sensitivity, specificity, PPV and NPV of FNA were 81%, 100%, 100% and 78% respectively. Conclusions: EUS-FNA with a 25-gauge needle system is a safe and reliable method for tissue sampling in pancreatic masses. There were no complications noted in our study. When compared to previously published studies, there is an expected complication rate of ∼2% with pancreatitis being the most concerning. Our study suggests that perhaps the smaller caliber 25-gauge needle causes less trauma during EUS-FNA and hence less complications. Further studies including randomized trials are needed to determine the comparative accuracy and safety of the 25-gauge needle system against other available needles.