Comparison of Capillary Versus Aspiration Technique in Endoscopic Ultrasound-Guided Fine-Needle Aspiration for Solid Pancreatic Lesions: Presidential Poster

Abstract

Introduction: Application of suction during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of solid pancreatic lesions is still controversial. The fine-needle stylet “capillary technique,” which uses only capillary aspiration achieved by slow withdrawal of the stylet has recently been proposed. The aim of this study was to compare the performance characteristics of EUS-FNA for evaluating solid pancreatic lesions using the standard “suction” and the “capillary” techniques. Methods: A retrospective review of consecutive patients with solid pancreatic lesions who underwent EUS-FNA using a 22 G needle from 2006 to 2013 was performed. Patients were divided into 2 groups: a) between 2002 and 2012, EUS-FNA was performed using the “suction” technique, and b) beginning 2013, FNA was performed using the “capillary” technique. Performance characteristics of EUS-FNA including the sensitivity, specificity, and the number of needle passes to obtain diagnosis were compared between the 2 groups. Results: A total of 973 patients (51% male; mean age 65.7 years) were evaluated. There was no difference between the groups in age, sex, and size of pancreatic mass. Cytological final diagnosis was adenocarcinoma in 81.8% cases, neuroendocrine tumor 4.7%, intraductal papillary mucosal neoplasms with high-grade dysplasia in 5.4%, metastatic disease in 4.4%, and negative for malignant cells in 3.7%. The sensitivity and specificity of EUS-FNA were higher in the “capillary” group when compared to the “suction” group (96.9, 100%, and 90.3, 81.7%, respectively; p=0.002). The numbers of passes required to obtain a diagnosis in the capillary group was two-thirds that of the suction group (incidence rate ratio 0.65; p<0.001). The mean number of needle passes required to make a diagnosis in the capillary group was significantly less when compared to the suction group (1.9 vs. 2.9, respectively; p=0.05). Conclusion: The “capillary” technique is superior to the traditional “suction” technique in EUS-FNA of solid pancreatic lesions in overall sensitivity, specificity, and on a per-pass basis. It can acquire a definitive tissue diagnosis on cytological smear in fewer passes and can potentially decrease risk to the patient.