Fine-needle tissue acquisition from subepithelial lesions using a forward-viewing linear echoendoscope.

Background and study aims: The overall diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS - FNA) for subepithelial lesions (SELs) is suboptimal. The aim of this study was to evaluate the diagnostic accuracy, defined as the proportion of correct diagnoses, obtained using the EUS-guided fine-needle tissue acquisition (FNTA) sampling technique performed with the newly developed forward-viewing EUS scope (FV-EUS). Patients and methods: This was a retrospective analysis of a prospectively collected database including all consecutive patients with SELs who underwent EUS - FNTA using the FV-EUS scope from 2007 to 2011 in a tertiary referral center. All procedures were performed by a single expert endoscopist. Results: A total of 121 consecutive patients with SELs (13 in the esophagus, 96 in the stomach, 10 in the duodenum, 2 in the rectum) underwent sampling of the lesion using the FV-EUS scope. The procedure was technically feasible in all but one patient, and no complication related to EUS - FNTA occurred. Full histological assessment including immunostaining could be completed in 93.4 % (113 /121) of the patients. Considering neoplastic vs. non-neoplastic diseases, the sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 92.8 % (95 %CI 86.3 - 96.8), 100 % (95 %CI 69.0 - 100 %), infinity, and 0.07 (95 %CI 0.04 - 0.14), respectively. Conclusions: EUS - FNTA performed in conjunction with the FV-EUS scope for sampling SELs of the gastrointestinal tract was safe and provided a very high diagnostic accuracy. Studies comparing FV-EUS with standard curved linear echoendoscopes are needed to clarify whether these results are due to the sampling technique or the type of scope utilized.