Tracking the target in colonic diverticular bleeding using red dichromatic imaging

Development and clinical usefulness of a unique red dichromatic imaging technology in gastrointestinal endoscopy: A narrative review

Image-enhanced endoscopy (IEE) allows real-time high-contrast imaging of a targeted lesion without any special equipment. Among various IEE technologies, narrow-band imaging, in which a light of shorter wavelength is used, emphasizes the surface and blood vessel patterns on the mucosal surface. This technology has been widely used in endoscopic diagnosis in the gastrointestinal tract. Red dichromatic imaging (RDI) was recently developed; it utilizes lights of longer wavelengths (520-550, 595-610, and 620-640 nm), which have weak light scattering characteristics in contrast to narrow-band imaging. RDI was designed to enhance the visibility of deep-lying blood vessels and areas of bleeding, and it has been installed in the latest Olympus endoscopy system, EVIS X1, as an advanced version of the optical-digital method that was originally developed. Improving the visibility of deep blood vessels allows more accurate evaluation of esophageal varices and the degree of inflammation in ulcerative colitis. Easier identification of a bleeding source makes hemostasis quicker and easier to accomplish during endoscopic resection procedures such as endoscopic submucosal dissection and peroral endoscopic myotomy as well as during treatment of gastrointestinal bleeding from a peptide ulcer or colon diverticulum. The authors herein review the technological development and principles, review the existing literature on RDI, and discuss the utility and effectiveness of this unique IEE technology in gastrointestinal endoscopy.

Evaluation of the visibility of bleeding points using red dichromatic imaging in endoscopic hemostasis for acute GI bleeding (with video)

BACKGROUND AND AIMS

We aimed to clarify whether red dichromatic imaging (RDI), a new type of image-enhanced endoscopy, improves the visibility of bleeding points in acute GI bleeding (AGIB) compared with white-light imaging (WLI).

METHODS

Images and videos of bleeding points acquired with WLI and RDI during endoscopic hemostasis for AGIB were retrospectively compared. In images, the color difference between bleeding points and surrounding blood was analyzed. In videos, 4 expert and 4 trainee endoscopists evaluated the visibility on a scale of 1 (undetectable) to 4 (easily detectable). Furthermore, the correlation between the color difference and visibility score was evaluated.

RESULTS

We analyzed 64 lesions. The color difference was significantly higher in RDI (13.11 ± 4.02) than in WLI (7.38 ± 3.68, P < .001). The mean visibility score for all endoscopists was significantly higher in RDI (3.12 ± .51) compared with WLI (2.72 ± .50, P < .001); this was also observed in experts (3.18 ± .51 vs 2.79 ± .54, P < .001) and trainees (3.05 ± .54 vs 2.64 ± .47, P < .001). The color difference and visibility score were moderately correlated for all endoscopists (γ = .56, P < .001) and for experts (γ = .53, P < .001) and trainees (γ = .57, P < .001).

CONCLUSIONS

RDI improves the visibility of bleeding points in AGIB compared with WLI. RDI can help endoscopists at all levels of experience to recognize bleeding points by enhancing the color contrast relative to surrounding blood.

Endoscopic submucosal dissection and tunneling procedures using novel image-enhanced technique

Background and Aims

Recent innovations in image-enhanced endoscopy allow early detection and management of GI lesions. In this study, we aim to analyze the utility of texture and color enhancement imaging (TXI) and red dichromatic imaging (RDI) during endoscopic submucosal dissection (ESD) and submucosal tunneling procedures.

Methods

Patients who underwent ESD, submucosal tunneling endoscopic resection, and peroral endoscopic myotomy (POEM) using the novel imaging technique including TXI and RDI were included in the study.

Results

Twenty-five patients (13 male; age 43 ± 15.69 years) underwent POEM for achalasia (n = 20), submucosal tunneling endoscopic resection for esophageal subepithelial lesions (n = 3), and ESD for gastric neuroendocrine tumors (n = 2). All of the procedures were successfully performed. Mean procedure duration was 55.52 ± 21.61 minutes. TXI mode was used in all the cases, whereas RDI mode was used on 15 occasions. While using RDI mode, hemostasis was achieved in 1 attempt on 12 (80%) occasions. The site of mucosal incision was revised in 3 cases during POEM based on TXI and RDI modes.

Conclusions

Submucosal tunneling and endoscopic dissection procedures can be conveniently performed using a new image-enhanced technique. RDI is useful in localizing the site of bleeding during endoscopic dissection.