FACTORS INFLUENCING DIAGNOSTIC ACCURACY OF ENDOSCOPIC ULTRASOUND WITH FINE NEEDLE ASPIRATION (EUS-FNA) IN PANCREATO-BILIARY TUMORS

Aims To evaluate the factors influencing diagnostic accuracy of EUS-FNA in patients with suspected pancreato-biliary tumors.

Methods From 2010 to 2018, 557 consecutive EUS-FNAs were carried out by a single operator using an echo endoscope Olympus GFUCT140 or GFUCT180. EUS FNAs were carried out using a needle of different type (Echotip ProCore, Wilson-Cook, Expect TM Boston Scientific, Shark Core TM FNB Medtronic, Acquire Boston Scientific) and with different size (19, 20, 22 Gauge).

Results 308/557 EUS-FNAs were carried out for pancreato-biliary neoplasms. Overall sensitivity of EUS-FNA was 66%, specificity 100%, and diagnostic accuracy 69%. When tissue sampling was performed using a new fine needle biopsy (FNB) (Acquire/Shark needles), the diagnostic accuracy increased up to 90.5%. When EUS-FNA was targeted to both primary and metastatic lesions (33 patients) sensitivity raised to 98%. Diagnostic accuracy was influenced by the experience of the operator, reaching 87.5% after 250 procedures. Variables associated with diagnostic accuracy were FNB needle (OR 3.06), operator expertise (OR 1.21) and EUS-FNA of primary and metastatic sites (OR 9.67).

Conclusions EUS-FNA is a safe procedure with high diagnostic accuracy in pancreato-biliary neoplasms. The diagnostic accuracy increases during the learning curve period, being necessary at least 250 EUS-FNAs to achieve a good (> 85%) value in the absence of ROSE.