A prospective, comparative trial to optimize sampling techniques in EUS-guided FNA of solid pancreatic masses

Background: There is no standardization of the use of suction during puncturing of a target in pancreatic EUS-guided FNA (EUS-FNA). It is also debatable whether expressing aspirates from the needle by the traditional method of reinserting the stylet is more effective than by air flushing, which is easier and safer. Objective: To optimize sampling techniques in pancreatic EUS-FNA. Design: Prospective, comparative trial. Setting: Tertiary-care referral center. Patients: Eighty-one consecutive patients with solid pancreatic masses. Intervention: Four punctures were performed for each mass in random order by a 2 × 2 factorial design. Sample quality and diagnostic yield were compared between samples with suction (S+) versus no suction (S-) and expressed by reinserting the stylet (RS) versus air flushing (AF). Main Outcome Measurements: Sample quality by the number of diagnostic samples, cellularity, bloodiness, and air-drying artifact; diagnostic yield by accuracy, sensitivity, and specificity. Results: The number of diagnostic samples (72.8% vs 58.6%; P =.001), cellularity (odds ratio [OR] 2.12; 95% confidence interval [CI], 1.37-3.30; P <.001), bloodiness (OR 1.46; CI, 1.28-1.68; P <.001), accuracy (85.2% vs 75.9%; P =.004), and sensitivity (82.4% vs 72.1%; P =.005) were higher in S+ than in S-. Bloodiness was lower in AF than in RS (OR 1.16; CI, 1.03-1.30; P =.017). Limitations: Single-center trial, 2 kinds of needle gauges, and no immediate cytopathology evaluation. Conclusion: Puncturing with suction and expressing by air flushing may be used preferentially in pancreatic EUS-FNA because they were more effective and convenient techniques. (Clinical trial registration number: NCT01354795.)