Optimizing Diagnostic Yield for EUS-Guided Sampling of Solid Pancreatic Lesions: A Technical Review

Abstract

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a higher diagnostic accuracy for pancreatic cancer than other techniques. This article will review the current advances and considerations for optimizing diagnostic yield for EUS-guided sampling of solid pancreatic lesions. Preprocedural considerations include patient history, confirmation of appropriate indication, review of imaging, method of sedation, experience required by the endoscopist, and access to rapid on-site cytologic evaluation. New EUS imaging techniques that may assist with differential diagnoses include contrast-enhanced harmonic EUS, EUS elastography, and EUS spectrum analysis. FNA techniques vary, and multiple FNA needles are now commercially available; however, neither techniques nor available FNA needles have been definitively compared. The need for suction depends on the lesion, and the need for a stylet is equivocal. No definitive endosonographic finding can predict the optimal number of passes for diagnostic yield. Preparation of good smears and communication with the cytopathologist are essential to optimize yield.

Keywords: Endoscopic ultrasound—guided fine-needle aspiration; fine-needle biopsy; pancreatic lesions.

Figures

Figure 1

Endoscopic ultrasound—guided fine-needle aspiration of a pancreatic mass.

Figure 2

A: The BNX system with 19 gauge (G), 22G, and 25G needles allows multiple needle exchanges through the outer sheath. (Image courtesy of Beacon Endoscopic and used with permission.) B: The Echo Tip ProCore needle has a reverse bevel design for acquiring a tissue specimen. The 22G and 25G needles are shown. C: A close-up view of the tip of the ProCore 25G needle. (Image courtesy of Cook Medical and used with permission.) D: The nitinol-based Expect Flex 19G fine aspiration needle is more flexible than its stainless steel predecessors and appears more promising for use in the duodenum. E: An extreme close-up view of the Expect 19G needle. (Image courtesy of Boston Scientific and used with permission.) F: The Clear View endoscopic ultrasound—guided fine aspiration needle. The distal 2 centimeters of the needle are laser-etched to enhance visibility. (Image courtesy of ConMed Endoscopic Technologies and used with permission.)