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 (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 were video-recorded separately and blindly reviewed by six experienced gastroenterologists. The sensitivity of the Aer-O-Scope 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 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 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, both the front-viewing and omnidirectional-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.

The Aer-O-Scope: proof of the concept of a pneumatic, skill-independent, self-propelling, self-navigating colonoscope in a pig model.

BACKGROUND AND STUDY AIMS: Considerable training is needed to enable endoscopists to use the currently available commercial colonoscopes and sigmoidoscopes effectively and safely. The aim of this study was to evaluate the safety and efficacy of the propulsion mechanism incorporated into the Aer-O-Scope (GI View Ltd., Ramat Gan, Israel)--a novel self-propelled, self-navigating colonic endoscope for diagnostic purposes. MATERIALS AND METHODS: Twenty young female pigs underwent complete bowel preparation followed by a sedated examination using the new device. Ten pigs underwent two consecutive procedures, with a wash-out period of 7 days between each procedure. The total number of procedures was 30. Two prototypes of the Aer-O-Scope, with different cable lengths and vehicle balloon sizes (n = 20 and n = 10 for prototypes I and II, respectively) were used. Each examination was followed by a standard colonoscopy for safety evaluation. The insertion length of the Aer-O-Scope was determined by fluoroscopy images. RESULTS: The colon was adequately clean in 25 procedures. Maximum insertion was achieved in 21 procedures (84%)--80% with prototype I (n = 15) and 90% with prototype II (n = 10). The time to maximum insertion averaged 8.9 +/- 4.4 min (10 +/- 4.6 and 6.6 +/- 2.9 min for prototypes I and II; P < 0.05), and the withdrawal time averaged 3.4 +/- 2.1 and 4.2 +/- 3.4 min, respectively. The driving pressures for prototypes I and II averaged 46.3 and 34.5 mbar, respectively. The follow-up conventional colonoscopy identified no mucosal tears or perforations. Minor mucosal petechiae were noted in 43% of the cases. No adverse events were noted up to 7 days after the procedure. CONCLUSIONS: The propulsion mechanism used in this novel self-propelled, self-navigating colonoscope was effective and safe in pigs.