Whole Colonic Endoscopic Ultrasound Using a Novel Device: In-Vivo Animal Study

Abstract

Background/aim: Traditionally, the majority of the use of endoscopic ultrasound (EUS) in the lower GI tract is limited to evaluation and diagnosis of diseases of the rectum. Advancing a regular echoendoscope to proximal part of colon is limited due to the side view design of the echoendoscope, poor resolution of probe-based ultrasound images and difficulties with acoustic coupling with the colon wall. The objective of this study is to evaluate the feasibility and safety of a novel endoscope accessory that allow whole colonic EUS evaluation. Methods: A prototype endoscope accessory device (EndoCompartmentTM) was created using an overtube with longitudinal closable seam equipped with balloons that allows creation of a working compartment within the GI tract. This novel overtube does not need pre-loading on the colonoscope prior to intubation and permits exchange of the colonoscope with an echoendoscope after identification of the need for EUS examination of the GI tract. The created compartment at the tip of the colonoscope can be filled with water that facilitates acoustic coupling of the echoendoscope with the wall of the colon and surrounding organs for creation of complete 360 degree EUS images. Results: We used a porcine model and after administering adequate sedation, an adult colonoscope was inserted into the colon and was advanced to the proximal colon. The overtube was opened along its length and was mounted over the exposed portion of the colonoscope. The overtube was then inserted into the colon over the colonoscope up to its tip. Using 2 balloons, a dynamic compartment was created The colonoscope was then withdrawn and an echoendoscope was inserted into the compartment which was filled with water and EUS images were obtained. The entire compartment along with echoendoscope could be moved along the colon without changing its elements while EUS images were obtained. We showed that EUS evaluation of the colon and surrounding tissue was technically feasible and safe in a live porcine model. Conclusion: It is possible to achieve a complete 360-degree view of the endoscopic ultrasound images of the colon and surrounding organs using a novel endoscope accessory (EndocopartmentTM).Figure 1Figure 2