Evaluation of two prototype convex linear array echoendoscopes for imaging and real-time fine needle aspiration of lesions within and adjacent to the gastrointestinal (GI) tract

Purpose: To evaluate the ability of two prototype convex linear array echoendoscopes to image lesions in the GI tract and to guide real-time fine needle aspiration (RTFNA). Methods: This prospective study was conducted by experienced endosonographers at two centers. Patients referred for endoscopic ultrasound (EUS) were considered for the study. Consenting patients underwent standard EUS (S-EUS) with the GIF UM-20 (Olympus, NY), followed by examination with either the Olympus XGF-UC3 (tip width 12mm, height 13.7mm) or the XGF-UC4 prototype (tip width 11.4mm, height 10.1 mm). RTFNA was performed of selected lesions with either the Olympus prototype needles (ABN-1, ABN-2) or the Mediglobe GIP needle. Results: Thirty-five patients underwent examination. In 24 patients, imaging of anatomy was performed without RTFNA using the XGF-UC3 (n=10) or XGF-UC4 (n=14). Imaged lesions were: mucosal (n=7), submucosal (n=4), pancreatic (n=8), biliary (n=3) and normal (n=2). In 11 patients, RTFNA was planned using the XGF-UC4. The lesions were: gastric submucosal lesions (n=7), duodenal mass (n=1), rectal mass (n=1) and mediastinal lymph node (n=1). Of these 11 planned RTFNAs, 5 were completed with an adequate biopsy sample (leiomyoma 2, lymphoma 1, inflammatory 2). In 5 cases an adequate biopsy sample was not obtained. RTFNA was not attempted in 1 patient whose procedure was terminated after S-EUS, before intubation with the prototype instrument. There was one complication related to the prototypes (perforation, XGF-UC3) in a patient with a mid-esophageal stricture who underwent Savary dilation and S-EUS prior to the examination with the prototype. Conclusions: Imaging the anatomy of the GI tract and adjacent structures is feasible with the Olympus XGF-UC3 and XGF-UC4. The XGF-UC4, with its smaller tip size, may be safer than the XGF-UC3 for maneuvering through strictured areas. These linear array instruments also allow performance of RTFNA. Further development of needle technology is needed to improve yield of EUS-guided FNA.