Evaluation of the severity of ulcerative colitis using endoscopic dual red imaging targeting deep vessels

Validation of red dichromatic imaging score (RDI score) to evaluate the severity of ulcerative colitis

BACKGROUND

Red dichromatic imaging (RDI) is a new imaging technology that has been closely correlated with the activity index of ulcerative colitis (UC). Although the RDI score has been developed no study has validated a correlation between the RDI score and the activity index of UC. Therefore, this study aims to validate the RDI score prospectively.

METHODS

A total of 34 patients with UC in whom colonoscopy was scheduled between May 2019 and October 2021 at our hospital were enrolled prospectively. MES, UCEIS, RDI scores, and Nancy index were evaluated in a blinded fashion. We evaluated the correlation between RDI and WLI scores using still images with histology.

RESULTS

We analyzed 191 sites of colorectum. RDI score showed the positive correlation with UCEIS (r = 0.74 P < 0.0001) and MES (r = 0.78 P < 0.0001). RDI score also showed the positive correlation with Nancy index (r = 0.63 P < 0.0001). RDI score was more strongly correlated with Nancy index than UCEIS (r = 0.51) and MES (r = 0.48).

CONCLUSIONS

When comparing still images of RDI and WLI scores, we showed RDI had a higher correlation to histology than WLI.

CLINICAL TRIAL ID

The University Hospital Medical Information Network (UMIN000041750).

Red dichromatic imaging reduces bleeding and hematoma during submucosal injection in esophageal endoscopic submucosal dissection

BACKGROUND

Bleeding and hematoma formation during submucosal injection in esophageal endoscopic submucosal dissection (ESD) reduce the visibility of the submucosa. Red dichromatic imaging (RDI) is an endoscopic technique that provides better visualization of the deep submucosal blood vessels. We speculated that blood vessel injury could be avoided with RDI. This pilot study evaluated the role of RDI in preventing bleeding and hematoma formation during esophageal ESD.

METHODS

This was a single-center retrospective observational study. We examined 60 patients who underwent ESD with white light imaging (WLI) and RDI. A single endoscopist reviewed all of the surgical videos to document the incidence and severity of bleeding episodes. Eighteen videos provided adequate quality and detail, and the number of blood vessels traversing the mucosal incision lines of the lesions in these videos was evaluated under WLI and RDI.

RESULTS

The WLI group had a significantly higher incidence of hematomas per unit area compared to the RDI group (0.18/cm² [range 0-0.38] vs. 0 [0-0.18]/cm², p = 0.024). The WLI group also had a significantly higher incidence of total bleeding episodes compared to the RDI group (42.9% [range 21.7-60.4] vs 16.7% [range 13.8-22.9], p < 0.001). Significantly more blood vessels were visible under RDI compared to WLI (5 [range 4-8] vs. 2 [range 1-5], p = 0.0020).

CONCLUSION

RDI reduced the incidence of bleeding and hematoma formation during submucosal injection in esophageal ESD. It was assumed that the improvement of blood vessel visibility by RDI might have contributed to the result.

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.

Clinically Available Optical Imaging Technologies in Endoscopic Lesion Detection: Current Status and Future Perspective

Endoscopic optical imaging technologies for the detection and evaluation of dysplasia and early cancer have made great strides in recent decades. With the capacity of in vivo early detection of subtle lesions, they allow modern endoscopists to provide accurate and effective optical diagnosis in real time. This review mainly analyzes the current status of clinically available endoscopic optical imaging techniques, with emphasis on the latest updates of existing techniques. We summarize current coverage of these technologies in major hospital departments such as gastroenterology, urology, gynecology, otolaryngology, pneumology, and laparoscopic surgery. In order to promote a broader understanding, we further cover the underlying principles of these technologies and analyze their performance. Moreover, we provide a brief overview of future perspectives in related technologies, such as computer-assisted diagnosis (CAD) algorithms dealing with exploring endoscopic video data. We believe all these efforts will benefit the healthcare of the community, help endoscopists improve the accuracy of diagnosis, and relieve patients' suffering.

Efficacy of a new image-enhancement technique for achieving hemostasis in endoscopic submucosal dissection

BACKGROUND AND AIMS

Hemostasis during endoscopic submucosal dissection (ESD) can sometimes be challenging and stressful for the endoscopist. Therefore, we aimed to assess the usefulness of dual red imaging (DRI), a new image enhancement technique that uses 3 wavelengths (540, 600, and 630 nm) to visualize bleeding points and to examine the efficacy of DRI in shortening the time required to achieve hemostasis (hemostasis time) during ESD.

METHODS

DRI and white-light imaging (WLI) were used alternately for managing 378 bleeding events in 97 patients undergoing ESD. Hemostasis time for each hemostasis event was measured. Using portable eye-tracking glasses, 4 experienced endoscopists were shown random videos of intraoperative bleeding during ESD (20 cases each on WLI and DRI) and identified the bleeding point in each video. The mean distances of eye movement per unit of time until the bleeding point were identified in each video and compared between the WLI and DRI groups.

RESULTS

Average hemostasis time was significantly shorter in the DRI group. The mean distance of eye movement was significantly shorter in the DRI group than in the WLI group for all endoscopists.

CONCLUSIONS

DRI can offer useful images to help in clearly detecting bleeding points and in facilitating hemostasis during ESD. It is feasible and may help in successfully performing ESD that is safer and faster than WLI. (Clinical trial registration number: UMIN000018309.).

Utility of Dual Red Imaging for Endoscopic Hemostasis of Gastric Ulcer Bleeding

Dual red imaging (DRI; Red Dichromatic Imaging (RDI)) is a new type of image-enhanced endoscopy composed of two long wavelengths that together can visualize vessels in the deep submucosa of the gastrointestinal wall. We treated a case of gastric ulcer bleeding in which the bleeding point could be clearly visualized using DRI. A 71-year-old man who was taking warfarin for atrial fibrillation noticed tarry stool, entered a state of hypovolemic shock, and underwent emergency esophagogastroduodenoscopy. The procedure was performed with a GIF-Y0058 prototype endoscope (Olympus Co., Tokyo, Japan) equipped with a DRI mode. An ulcer with active bleeding was found in the upper portion of the stomach, but the massive volume of the bleeding made it difficult to identify the bleeding point using white light imaging (WLI). Upon switching to DRI mode by pushing a button on the endoscope, the bleeding point could be identified rapidly and precisely, as it appeared in a deeper yellow than the surrounding area. Complete hemostasis was thereupon achieved. This case demonstrates that the DRI mode may be useful for detecting bleeding points that are difficult to detect using WLI.

Dual red imaging: a novel endoscopic imaging technology visualizing thick blood vessels in the gastrointestinal wall

Background  Dual red imaging (DRI), a novel image-enhanced endoscopy (IEE) technology, has the potential to improve the visibility of blood vessels in deeper tissue using 600 nm and 630 nm wavelength lights in the red band. Aim  To confirm the feasibility of DRI in visualization of vessels in deeper tissue and identify pathologically the features of blood vessels visualized by DRI. Methods  Study 1: visibility of blood vessels was assessed by five observers in 137 pairs of DRI and white light imaging (WLI) images. The scores for the visibility of thick blood vessels were measured for randomized images and compared with the scoring template as a reference. The difference in visibility score between DRI and WLI was compared in each pair of images. Study 2: blood vessels detected only by DRI were examined pathologically using two pig stomachs. Results  Study 1: The mean visibility scores of DRI and WLI for each observer were 1.69 - 2.26 and 1.31 - 1.67, respectively. The mean difference in visibility score and 95 % confidence interval for the five observers was 0.59 [0.46 - 0.72], 0.54 [0.40 - 0.68], 0.34 [0.18 - 0.49], 0.51 [0.36 - 0.66], and 0.71 [0.54 - 0.88]. The visibility was statistically significantly better in DRI than in WLI for all observers ( P  < 0.0001). Study 2: three blood vessels were observed only by DRI. All of these blood vessels were located at a depth of 1000 - 1500 µm from the mucosal surface. The diameter of these blood vessels exceeded 80 - 200 µm. Conclusions  DRI can feasibly detect thick blood vessels in the deep mucosa or submucosa of the gastrointestinal tract.

Clinical Usefulness of Dual Red Imaging in Gastric Endoscopic Submucosal Dissection: A Pilot Study

Background/Aims

Dual red imaging (DRI) is a new, image-enhanced endoscopy technique. There are few reports about the usefulness of DRI during gastric endoscopic submucosal dissection (ESD). We aimed to examine the usefulness of DRI in endoscopic hemostasis during gastric ESD.

Methods

We enrolled a total of 20 consecutive patients who underwent gastric ESD. Five endoscopists compared DRI with white light imaging (WLI) for the visibility of blood vessels and bleeding points while performing endoscopic hemostasis.

Results

The visibility of blood vessels was increased in 56% (19/34) of the cases, and the visibility of bleeding points was improved in 55% (11/20) of the cases with the use of DRI compared with the use of WLI.

Conclusions

DRI improved the visibility of blood vessels and bleeding points in cases with oozing bleeding, blood pooling around the bleeding points, and multiple bleeding points.

Haemostasis treatment using dual red imaging during endoscopic submucosal dissection: a multicentre, open-label, randomised controlled trial

INTRODUCTION

Patients scheduled to undergo oesophageal, gastric and colorectal endoscopic submucosal dissection (ESD) are to be investigated to verify the efficacy of dual red imaging (DRI) for establishing haemostasis during ESD.

METHODS AND ANALYSIS

The trial is designed as a multicentre, open-label randomised, parallel-group, controlled intervention study. Registered patients will be randomly assigned to DRI and white light imaging (WLI) groups. In the DRI group, the mucosal incision and submucosal dissection will be performed by WLI, and haemostasis will be managed by DRI when bleeding occurs. In the WLI group, the mucosal incision and submucosal dissection are to be performed by WLI and the haemostasis management is to be performed by WLI. The primary endpoint is the time from the recognition of bleeding up to the achievement of complete haemostasis (haemostasis time). The secondary endpoints are the operation time, the proportion of cases in which perforation occurs, and the psychological stress experienced by the endoscopist during haemostasis treatment.

ETHICS AND DISSEMINATION

This trial was approved by the Keio University Review Board for Clinical Trials (5 December 2016).

DISCUSSION

This will be the first multicentre collaborative research using DRI for haemostasis treatment during ESD. When the safety and simplicity of DRI as a treatment for haemostasis during ESD can be proven, the ESD procedure can be simplified and disseminated more widely in clinical practice.

TRIAL REGISTRATION NUMBER

UMIN000025134.

Dual Red Imaging Maintains Clear Visibility During Colorectal Endoscopic Submucosal Dissection

BACKGROUND

The endoscopic lens becomes clouded and its visibility reduces during colorectal endoscopic submucosal dissection (ESD), especially in cases with submucosal fatty tissue. Dual red imaging (DRI) is a novel image-enhanced endoscopic technique that improves endoscopic visibility.

AIMS

This study aimed to evaluate the predictive factors of submucosal fatty tissue and the clinical usefulness of DRI in maintaining clear visibility during colorectal ESD.

METHODS

The study participants included 586 consecutive patients with 645 colorectal tumors who underwent ESD between January 2014 and July 2017. First, the degree of submucosal fatty tissue was evaluated by reviewing recorded images, and the clinical characteristics of the patients and tumors related to severe submucosal fatty tissue were evaluated. Second, 34 tumors resected using DRI were propensity score-matched in a 1:1 ratio to other resected tumors using white light imaging (WLI), and the degree of endoscope lens cloudiness and clinical outcomes were evaluated.

RESULTS

The proportion of tumors located in the right side of the colon, body mass index (≥ 25, BMI), and hemoglobin A1c (≥ 6.5%, HbA1c) were significantly higher in patients with severe submucosal fatty tissue. The visibility in the DRI group was significantly better than in the WLI group. Treatment outcomes in the DRI group were as good as those in the WLI group.

CONCLUSIONS

Tumor location in the right side of the colon, BMI (≥ 25), and HbA1c (≥ 6.5%) are the predictive factors of severe submucosal fatty tissue. DRI is useful in maintaining clear visibility during colorectal ESD, especially with submucosal fatty tissue.