Preliminary clinical experience with high-definition colonoscope illuminated by light-emitting diode.

Thedevelopmentof gastrointestinal endoscopes has been closely related to innovations in light sources and observation devices [1]. We anticipated that the lightemitting diode (LED) might be useful for innovation of the gastrointestinal endoscopesystemand started the development of a test scopewithwhite LEDson its tip [2, 3]. The LED gastrointestinal endoscope does not need a large light source apparatus or light-guiding fiber bundle. Furthermore, the LED gastrointestinal endoscope system may be manufactured simply at low cost and is relatively independent of a power supply infrastructure. In cooperation with Fujifilm Corporation (Tokyo, Japan) and Yamaguchi University, our group has developed a high-definition colonoscope that uses white LEDs (●" Fig.1). Image-enhanced endoscopy (IEE) with flexible spectral imaging color enhancement (FICE) is also possible. For a preliminary evaluation of the image quality of the high-definition LED colonoscope, weperformedobservationsmainlyofnondiseased colorectal mucosa in patients with colorectal disease at the National Hospital Organization Kanmon Medical Center. We obtained written informed consent from all patients and the study had the approval of the institutional review board. From July 2010 to September 2011, we performed 10 sigmoidoscopies and 4 total colonoscopies in 14 patients. The patients were nine women and five men, and their mean age was 66.9 years (range 43–87 years). Four patients had colorectal cancer, nine had previously undergone colorectal polypectomy, and one patient had ulcerative colitis. The study was performed safely without any incident or malfunction of the scope system. Using the high-definition LED colonoscope, the vascular structure of the colorectal mucosa was observed clearly (●" Fig.2a). The luminous intensity was sufficient for observation of the colorectal lumen. The light was evenly distributed in the lumen, which may be related to the wide opening of the LED package surface. Usedwith flexible imaging color enhancement, the fine vascular structure was clearly observed without any magnifying mechanism (●" Fig.2b). This preliminary study indicates the potential usefulness of the high-definition LED colonoscope, not only for screening of colon polyps, but also for fine diagnosis of superficial colorectal cancers. The use of scope tip illumination may evoke a major platform innovation of the gastrointestinal endoscope system. This system would also be suitable for mobile hospitals and endoscopy units [4]. The low cost and reduced dependency on electrical power infrastructure of the LED gastrointestinal endoscope system will contribute to worldwide dissemination of high-level gastrointestinal endoscopy and gastrointestinal cancer screening [5].