Su2041 A Novel Dual-View Probe That Produces a Single Image and Improves Polyp Detection

Abstract

Background: Colonoscopy is the procedure of choice for colon cancer screening, but is far from perfect, as lesions are missed due to lack of image contrast and due to their location behind haustral folds and at flexures. We have developed a novel dual-view optical probe that illuminates and images in the forward and omni-directional rear directions to provide a single registered video image. Objective: Evaluate the prototype dual-view probe in a standard colon model. Design: A colon model (Chamberlain Group, MA) was used for the study. Due to the stiffness of the model and the difficulty in advancing a colonoscope through it, the colon was cut into 3 sections (ascending, transverse, and descending colon) and the ends sealed to prevent leakage of light. A total of 31 red spheres and discs (to represent polyps and flat lesions) were glued to the inner surface of the model; approximately half were located in easily visible areas between folds, whereas the rest were placed in difficult to see locations proximal to folds. A research fellow advanced a standard colonoscope (Fujinon EC530-HL, Fujifilm, Wayne, NJ) with 140 degree forward view to the sealed end of each segment. The image was shown on a standard flat panel display. Each endoscopist (2 attendings, 2 fellows) examined the three colon segments with the room lights darkened. Polyps detected were called out by the endoscopist and recorded by research staff. The dual-view probe was subsequently attached to the tip of the colonoscope and the procedure repeated by each endoscopist 14 days later (so that location of polyps could not be recalled) using the dual-view probe's own light source and image display Results: Out of a total of 31 lesions a mean of 18.8 ± 2.2 lesions were visualized using standard forward-viewing colonoscope, whereas 29.3 ± 1.3 (an increase of 56%) were detected with the dual-view probe (p< 0.005, t-test). Limitations: Commercially available models made maneuverability of the colonoscope and probe difficult, necessitating the model to be cut into 3 segments. The size of this first proof of concept dual-view prototype is too large to be passed through the biopsy channel of a colonoscope and its attachment to the tip of the endoscope further limited flexion of the scope tip. Conclusions: The novel proof of concept dual-view probe is the first optical device to display both a forward and 360-degree rear-view image in the vertical plane in a single registered display. A single display allows both the forward and rear images to be viewed with ease. Imaging with the dual-view probe substantially improved polyp detection, particularly those located behind haustral folds. Ongoing work to reduce the size of the dual-view probe will allow it to be passed through a standard colonoscope for testing in patients.