Newly-developed, forward-viewing echoendoscope: a comparative pilot study to the standard echoendoscope in the imaging of abdominal organs and feasibility of endoscopic ultrasound-guided interventions

Abstract

Background and aim: Multiple diagnostic and therapeutic endoscopic ultrasound (EUS) procedures have been widely performed using a standard oblique-viewing (OV) curvilinear array (CLA) echoendoscope. Recently, a new, forward-viewing (FV) CLA was developed, with the advantages of improved endoscopic viewing and manipulation of devices. However, the FV-CLA echoendoscope has a narrower ultrasound scanning field, and lacks an elevator, which might represent obstacles for clinical use. The aim of this study was to compare the FV-CLA echoendoscope to the OV-CLA echoendoscope for EUS imaging of abdominal organs, and to assess the feasibility of EUS-guided interventions using the FV-CLA echoendoscope.

Methods: EUS examinations were first performed and recorded using the OV-CLA echoendoscope, followed immediately by the FV-CLA echoendoscope. Video recordings were then assessed by two independent endosonographers in a blinded fashion. The EUS visualization and image quality of specific abdominal organs/structures were scored. Any indicated fine-needle aspiration (FNA) or intervention was performed using the FV-CLA echoendoscope, with the OV-CLA echoendoscope as salvage upon failure.

Results: A total of 21 patients were examined in the study. Both echoendoscopes had similar visualization and image quality for all organs/structures, except the common hepatic duct (CHD), which was seen significantly better with the FV-CLA echoendoscope. EUS interventions were conducted in eight patients, including FNA of pancreatic mass (3), pancreatic cyst (3), and cystgastrostomy (2). The FV-CLA echoendoscope was successful in seven patients. One failed FNA of the pancreatic head cyst was salvaged using the OV-CLA echoendoscope.

Conclusions: There were no differences between the FV-CLA echoendoscope and the OV-CLA echoendoscope in visualization or image quality on upper EUS, except for the superior image quality of CHD using the FV-CLA echoendoscope. Therefore, the disadvantages of the FV-CLA echoendoscope appear minimal in light of the potential advantages.