Proof-of-concept study of the Aer-O-Scope™ omnidirectional colonoscopic viewing system in ex vivo and in vivo porcine models

Background and study aims: The limited angle of view of standard colonoscopes means that lesions can be missed. A multidirectional viewing system (OmniVision) has been developed recently and has been incorporated into the Aer-O-Scope (TM) (GI View Ltd., Ramat Gan, Israel), a disposable, self-propelling, and self-navigating colonoscope. The objectives of this study were to qualitatively assess the sensitivity of this viewing system in an ex vivo porcine polyp induction model, and to demonstrate its feasibility and safety in live pigs. Materials and methods: For the ex vivo part of the study, six red metal beads of various sizes were randomly sewn into the mucosa of an unfolded, 2-meter-long porcine colonic segment. Seven passages of the Aer-O-Scope (TM) were video-recorded separately and blindly reviewed by six experienced gastroenterologists. The sensitivity of the Aer-O-Scope (TM) to detect beads of various sizes was calculated. For the in vivo experiment, in a repeated-measure study, nine female domestic pigs were examined with the Aer-O-Scope (TM) with the OmniView optics, followed immediately by examination with standard optical colonoscopy in order to assess the integrity of the colonic mucosa. Results: In the ex vivo study the sensitivity of the Aer-O-Scope (TM) was 97.6% (CI 94.0%-100%) for any bead (i.e. any "polyp"). The rate of polyp detection was similar for the six endoscopists, and was consistent for all bead sizes. The average false-positive rate was 0.3% polyps per run (SD 0.61%). The mean time taken for the video assessment was 8.0 minutes (SD 4.0 minutes). In the in vivo experiments with the Aer-O-Scope (TM), both the front-viewing and onmidirectional-viewing systems were functional in all cases. The colon in front of the optical capsule was well distended and a complete and meticulous inspection of the entire colonic mucosa was performed in all the pigs. There were no adverse events. Conclusions: The OmniVision system allows for a highly sensitive inspection of the colonic mucosa without the need for tip manipulation. Clinical studies are warranted in order to validate these results in humans.