Reduced Loop Formation Using a Computer-Assisted Colonoscope (the NeoGuide System) Compared with Standard Colonoscopy

Abstract

Background: Colonoscopy is an uncomfortable procedure for most patients. Most procedures are performed using some combination of anxiolytic and analgesic medication. Discomfort during colonoscopy is largely related to looping of the colonoscope, which displaces the colon from its natural configuration and stretches attachments to the mesentery (Shah, et. al. Endoscopy 2002;34(6):435-440). The NeoGuide system (NeoGuide Systems, Inc., Los Gatos, CA) utilizes a fully articulated, computer-controlled insertion tube that allows proximal segments of the colonoscope to follow the path taken by the tip as it is manually advanced though the colon. We hypothesized that this novel design would decrease the amount of colonic displacement due to loop formation. Methods: Ten gastroenterologists of varying levels of experience performed colonoscopy on a latex-based training simulator (Koken Colonoscopy Training Model 1-B, Koken Co., Tokyo, Japan). Procedures were performed with the NeoGuide system and with a standard production model colonoscope (Olympus America Inc., Melville, NY). Colonic displacement was recorded with a video camera mounted above the simulator. Each of 26 procedures (including six duplicates used as internal controls) was independently reviewed by six gastroenterologists who were blinded to the type of instrument used. Each physician was shown four images for each procedure, depicting the maximum degree of looping in the sigmoid, descending colon, transverse colon, and ascending colon for that procedure. Each evaluating endoscopist was asked to apply a numerical score between 0 and 5 corresponding to the maximum colonic displacement observed at any location. Results: All colonoscopies were successfully completed with both instruments. Mean displacement was significantly lower for procedures performed with the NeoGuide system than with the standard production model colonoscope (2.36 vs. 4.26, p < 0.001). Inter-observer agreement regarding degree of colonic displacement due to looping was moderate (weighted kappa = 0.45, p < 0.01). There was excellent agreement regarding relative ranks of looping (Kendall's coefficient = 0.77, p < 0.001). Conclusions: Colonoscopy with the NeoGuide computer-assisted colonoscope system was associated with significantly less looping than with a standard production model colonoscope. The reduced amount of looping suggests that procedures performed in patients may be associated with less discomfort and thus require less sedation. Clinical trials are warranted to determine if procedures performed with a computer-assisted colonoscope are more comfortable and better tolerated by patients.