Original Articles
Influence of EUS training and pathology interpretation on accuracy of EUS-guided fine needle aspiration of pancreatic masses☆

https://doi.org/10.1067/mge.2002.123419Get rights and content

Abstract

Background: Identification, staging, and fine needle aspiration of pancreatic mass lesions are probably the most technically demanding EUS skills. This study evaluated the effect of formal training on the diagnostic accuracy of EUS-guided fine needle aspiration (EUS-FNA) of pancreatic masses and the source of the variability in diagnostic accuracy between initial and later procedures. Methods: Sixty-five patients with pancreatic masses underwent EUS-FNA between April 1998 (introduction of EUS-FNA) and August 1999, 20 of whom were examined by 3 endosonographers without prior experience with EUS-FNA. The initial experience of these 3 endosonographers (April to December 1998; group A patients), which included a formal training period of 2 months, and their later experience (January to August 1999; group B patients) were evaluated. Final diagnoses were determined by surgical pathology or clinical follow-up. All EUS-FNA samples were reviewed by 4 blinded pathologists to determine the contribution of pathologist interpretation to varying EUS-FNA accuracy. Results: After a short training period, there was a significant improvement in EUS-FNA accuracy (33% vs. 91%; p = 0.004). After pathology review, good agreement was identified between original FNA interpretation and that on review (kappa = 0.78; 95% CI [0.5, 1.0]). There were differences between the mean cellularity score (2.8 vs. 1.8, p = 0.01) and mean number of passes (5.1 vs. 2.8, not significant) for correct versus incorrect FNA specimens. Conclusion: Significant improvements in EUS-FNA accuracy can be achieved with a short period of mentored training. EUS-FNA errors during the initial learning phase are primarily due to inadequate specimens. Interpretation of pancreatic EUS-FNA specimens remained consistent before and after training. (Gastrointest Endosc 2002;55:669-73.)

Section snippets

Patients and methods

EUS-FNA was introduced at our institution in April 1998. From then until August 1999, a total of 65 patients underwent EUS-FNA of a pancreatic mass. No patient had evidence of metastatic disease on prior cross-sectional imaging. Twenty EUS-FNA procedures were performed by 3 endosonographers with extensive EUS experience (more than 300 examinations including more than 100 of the pancreas) who had limited experience with EUS-FNA (less than 10 procedures of which fewer than 5 included EUS-FNA of

Results

The experience of 3 endosonographers with EUS-FNA of pancreatic mass lesions was examined in a series of 20 patients with pancreatic mass lesions who were divided into 2 groups based on whether the procedure was performed during the early (group A) or later (group B) experience of the endosonographers. Later experience pertained to EUS-FNA performed after several mentored training procedures that were not included in the analysis. Patient characteristics, location and size of the masses, mean

Discussion

The value of EUS and EUS-FNA in clinical practice depends on whether reported high rates of accuracy can be reproduced by individual endosonographers. EUS-FNA is highly accurate in expert hands, but real clinical utility is achieved only if nonexperts can approximate this accuracy within a reasonable period of time based on experience in a relatively small number of patients. The findings of the present study support the existence of a “learning curve” effect for EUS-FNA of pancreatic masses.

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☆

Reprint requests: Maurits J. Wiersema, MD, Eisenberg 8A, Mayo Clinic, 200 First St., SW, Rochester, MN 55905.

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Copyright © 2002 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.