Preclinical Evaluation of a Microwave-Based Accessory Device for Colonoscopy in an In Vivo Porcine Model with Colorectal Polyps

SIMPLE SUMMARY: Colonoscopy is the most effective method for colorectal cancer prevention but has several drawbacks that result in polyp miss rates. Microwave imaging is a novel solution that can obtain images of the colon based on the capacity of detecting changes in the dielectric properties of tissues. The aim of the current study is to evaluate, for the first time, the feasibility of a microwave-based accessory device for colonoscopy in an in vivo porcine model. We developed a device provided with microwave antennas and attached it to a conventional endoscope. In this preclinical model, the device did not impair endoscopic vision and was compatible with endoscopic tools; deep mural injuries were not observed and different signals were obtained from polyps and healthy mucosa, confirming its usability and potential of detecting polyps. ABSTRACT: Background and Aims: Colonoscopy is currently the most effective way of detecting colorectal cancer and removing polyps, but it has some drawbacks and can miss up to 22% of polyps. Microwave imaging has the potential to provide a 360° view of the colon and addresses some of the limitations of conventional colonoscopy. This study evaluates the feasibility of a microwave-based colonoscopy in an in vivo porcine model. Methods: A prototype device with microwave antennas attached to a conventional endoscope was tested on four healthy pigs and three gene-targeted pigs with mutations in the adenomatous polyposis coli gene. The first four animals were used to evaluate safety and maneuverability and compatibility with endoscopic tools. The ability to detect polyps was tested in a series of three gene-targeted pigs. Results: the microwave-based device did not affect endoscopic vision or cause any adverse events such as deep mural injuries. The microwave system was stable during the procedures, and the detection algorithm showed a maximum detection signal for adenomas compared with healthy mucosa. Conclusions: Microwave-based colonoscopy is feasible and safe in a preclinical model, and it has the potential to improve polyp detection. Further investigations are required to assess the device’s efficacy in humans.