Basic techniques in endoscopic ultrasound-guided fine-needle aspiration: Role of a stylet and suction

There are several variables that have been studied to optimize various outcomes of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) such as quality and adequacy of specimens, diagnostic yield of malignancy, accuracy and overall efficiency. Using an evidence-based approach, the objectives of this review are to discuss two key aspects of EUS-FNA: (a) Use of a stylet and (b) use of suction. Level 1 evidence available from randomized controlled trials demonstrates that the use of a stylet during EUS-FNA has no impact on the diagnostic yield of malignancy or the quality of specimens. Air flushing in a slow, controlled fashion is superior to reinsertion of a stylet to express EUS-FNA aspirates. The use of suction should be considered during EUS-FNA of pancreatic masses. However, data from a randomized controlled trial suggest that suction should not be used during EUS-FNA of lymph nodes as it increases bloodiness of specimens obtained and has no impact on the overall diagnostic yield.