Dual red imaging (novel advanced endoscopy) can increase visibility and can predict the depth in diagnosing esophageal varices

Improved visibility of palisade vessels within Barrett's esophagus using red dichromatic imaging: a retrospective cross-sectional study in Japan

BACKGROUND/AIMS

Visualization of palisade vessels (PVs) in Barrett's esophagus is crucial for proper assessment. This study aimed to determine whether red dichromatic imaging (RDI) improves PV visibility compared with white-light imaging (WLI) and narrow-band imaging (NBI).

METHODS

Five expert and trainee endoscopists evaluated the PV visibility in Barrett's esophagus using WLI, NBI, and RDI on 66 images from 22 patients. Visibility was rated on a 4-point scale: 4, excellent; 3, good; 2, fair; and 1, poor. The color difference between the most recognizable PV spots and surrounding areas with undetectable blood vessels was also analyzed.

RESULTS

Mean visibility scores were 2.6±0.7, 2.3±0.6, and 3.4±0.4 for WLI, NBI, and RDI, respectively. The RDI scores were significantly higher than the WLI (p<0.001) and NBI (p<0.001) scores. These differences were recognized by trainees and expert endoscopists. Color differences in PVs were 7.74±4.96 (WLI), 10.43±5.09 (NBI), and 15.1±6.54 (RDI). The difference in RDI was significantly higher than that in WLI (p<0.001) and NBI (p=0.006).

CONCLUSIONS

RDI significantly improved PV visibility compared to WLI and NBI based on objective and subjective measures.

Clinical outcomes of endoscopic submucosal dissection for esophageal squamous cell carcinoma with esophageal varices: Multicenter retrospective study

OBJECTIVES

Clinical outcomes of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) with esophageal varices (EVs) are obscure. We aimed to elucidate the clinical outcomes of ESD for ESCC with EVs in a multicenter, retrospective study.

METHODS

We established a retrospective cohort of 30 patients with ESCC complicating EVs, who underwent ESD at 11 Japanese institutions. Rates of en bloc resection and R0 resection, procedure time, and adverse events were evaluated as indicators of the feasibility and safety of ESD. Additional treatment, recurrence, and metastasis of the lesions were evaluated as indicators of the long-term efficacy of ESD.

RESULTS

Portal hypertension was caused by cirrhosis, of which alcohol was the most common cause. En bloc resection was achieved in 93.3% and R0 resection in 80.0% of the patients. The median procedure time was 92 min. Adverse events included a case of uncontrolled intraoperative bleeding leading to discontinuation of ESD and a case of esophageal stricture due to extensive resection. During the follow-up period of a median for 42 months, a patient with local recurrence and another patient with liver metastasis were observed. One patient died of liver failure after receiving chemoradiotherapy as an additional treatment after ESD. No patient died of ESCC.

CONCLUSION

This multicenter, retrospective cohort study demonstrated the safety and efficacy of ESD for ESCC with EVs. Further studies are needed to establish appropriate treatment methods for EVs before ESD and additional treatments for patients with insufficient ESD.

Red Dichromatic Imaging Improves the Recognition of Bleeding Points During Endoscopic Submucosal Dissection

BACKGROUND

Previous studies have indicated that red dichromatic imaging (RDI) improved the visibility of gastrointestinal bleeding.

AIMS

To investigate the recognition of bleeding points during endoscopic submucosal dissection (ESD) under RDI compared with that under white light imaging (WLI).

METHODS

Consecutive patients scheduled to undergo esophageal or gastric ESD at a single center were enrolled. Paired videos of active bleeding during ESD under WLI and RDI were created. Six endoscopists identified the virtual hemostasis point on still images after random video viewing. The distance between virtual hemostasis and actual bleeding points was scored in four levels (0-3 points), and the association with the color value was analyzed in both WLI and RDI.

RESULTS

We evaluated 116 videos for 58 bleeding points. The median visibility score and recognition rate were significantly higher for RDI than for WLI (2.17 vs. 1.42, p < 0.001 and 62.1% vs 27.6%, p < 0.001). Additionally, the recognition rate of trainees in RDI was higher than that of experts in WLI (60.3% vs. 43.1%, p = 0.067). The median color difference of RDI was significantly higher than that of WLI (8.97 vs. 3.69, p < 0.001). Furthermore, the correlation coefficient between the visibility score and color difference was 0.712 (strong correlation).

CONCLUSION

RDI can provide better recognition of bleeding points than WLI during ESD. Therefore, further studies are warranted to investigate whether RDI improves ESD outcomes.

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.

Red dichromatic imaging reduces endoscopic treatment time of esophageal varices by increasing bleeding point visibility (with video)

BACKGROUND

Red dichromatic imaging (RDI) is a novel image-enhanced endoscopy released in 2020, which increases the visibility of deeper vessels. In this study, we retrospectively investigated whether RDI can shorten treatment times of endoscopic injection sclerotherapy (EIS), and which operational procedure times are affected compared with white light imaging (WLI).

METHODS

A total of 155 patients (RDI, 70; WLI, 85) with risky esophageal varices (EV), who were treated with EIS were analyzed. Treatment times were compared, and predictors associated with treatment time were analyzed by multivariate analysis. For 24 cases (RDI, 12; WLI, 12) in which treatment videos were recorded, the procedure times of each step (observation of EV, needle flush, positioning, puncture, observation of bleeding, hemostasis, observation after hemostasis) were measured. Regarding the seven patients with EV bleeding, color differences were calculated between the bleeding point and the blood pool using the CIE (L*a*b*) color measurement method, and results were compared between using RDI and WLI.

RESULTS

Treatment times were shorter in the RDI group (RDI vs. WLI = 35.1 vs. 42.2 min; P < 0.01). 'RDI function' and 'amount of sclerosant' were extracted as independent predictors of treatment time. Times for 'observation of EV' and 'observation of bleeding' were shorter in the RDI group (P = 0.01 and <0.01, respectively). Regarding the color difference, RDI significantly increased bleeding point visibility (RDI vs. WLI = 31.4 ± 11.8 vs. 8.6 ± 6.2, P < 0.001).

CONCLUSION

Red dichromatic imaging can shorten the treatment time of EIS by increasing bleeding point visibility.

Red dichromatic imaging in peroral endoscopic myotomy: a novel image-enhancing technique

Video 1Red dichromatic imaging in peroral endoscopic myotomy.

Secure intravariceal sclerotherapy with red dichromatic imaging decreases the recurrence rate of esophageal varices: A propensity score matching analysis

BACKGROUND

Red dichromatic imaging (RDI) is next-generation image-enhanced endoscopy technique released in July 2020. We previously reported that RDI can predict esophageal varices (EV) depth and decrease their recurrence rate by accurate intravariceal injections during endoscopic injection sclerotherapy (EIS) using unreleased prototype RDI endoscope. In this study, we analyzed whether RDI improves the overall survival (OS) rate and whether it is more accurate independent predictor of EV recurrence than white light imaging (WLI), using propensity score matching.

METHODS

A total of 179 patients were enrolled. Patients were matched for age, platelet count, liver function, EV size, luminal diameter, and EV depth using propensity score matching, and 78 patients (RDI, 39; WLI, 39) were finally matched. Primary endpoints were OS and recurrence rates. Secondary endpoints were success rate of intravariceal injection, operating time, incidence of adverse events (AEs), and predictors associated with OS and recurrence rates.

RESULTS

There was no difference in OS (P = .193), but the cumulative recurrence rate in the RDI group was significantly lower than in the WLI group (P = .002). Success rates of intrainjection, operating time, and incidence of AEs were better in the RDI group (p = 0.035, .026, and .0019, respectively). Independent predictors associated with recurrence rate by Cox proportional regression were RDI function and luminal diameter (P < .001 and .017, respectively).

CONCLUSION

RDI did not improve OS but decreased the recurrence rate. Independent predictors of recurrence rate were RDI and luminal diameter, resulting from secure intravariceal injections in EIS.

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.

Role of dual red imaging to guide intravariceal sclerotherapy injection of esophageal varices (with videos)

BACKGROUND AND AIMS

Dual red imaging (DRI) is a novel image-enhanced endoscopy technique that can increase the visibility and predict the depth of esophageal varices (EVs). The recurrence rate of EVs after endoscopic injection sclerotherapy (EIS) reportedly decreases by intravariceal injection of a sclerosant. We evaluated prospectively whether the EIS success rate was increased by DRI compared with the white-light imaging (WLI) mode.

METHODS

A total of 79 patients with EVs were randomly divided into the DRI (n = 40) and WLI (n = 39) groups. The primary endpoint was the success rate of intravariceal injection on the first EIS puncture. The secondary endpoint was the recurrence rate. A variable puncture needle was used, and the length was adjusted according to the EV visibility change by DRI. In the WLI group, DRI was not used.

RESULTS

The success rate of the first puncture was significantly higher in the DRI group than in the WLI group (80.0% vs 46.2%; P = .0018). The cumulative recurrence rate was significantly lower in the DRI group (P = .031). The sum of the depth and luminal diameter of EVs was investigated by EUS. The Pearson correlation coefficient between this value and the needle length was higher in the DRI group than in the WLI group (r = 0.878 vs 0.603).

CONCLUSIONS

DRI increased the EIS success rate and decreased the recurrence rate. This resulted from the puncture needle adjustment to the appropriate length via EV depth prediction by DRI.

Narrow-band imaging can increase the visibility of fibrin caps after bleeding of esophageal varices: a case with extensive esophageal candidiasis

A 58-year-old man with hepatitis B cirrhosis noticed black stools and underwent an endoscopy at a community hospital. The presence of esophageal varices (EVs) was confirmed, but the bleeding point was not found. He was referred to our institution and underwent a second endoscopy. Extensive white patches of esophageal candidiasis were visible on endoscopy by white-light imaging (WLI), but it was difficult to find the fibrin cap of the EVs. This was easier under narrow-band imaging (NBI), however, as the color turned red from absorption by hemoglobin adhered to it. We retrospectively measured the color differences (CD) between the fibrin cap and the surrounding mucosa 10 times using the CIE (L*a*b*) color space method. The median value of CD increased after NBI (13.9 → 43.0, p < 0.001), with increased visibility. However, the median CD between the white patch and surrounding mucosa decreased after NBI (44.8 → 30.3, p < 0.001). The fibrin cap was paler than the white patch of candidiasis, but the increased visibility of the fibrin cap by NBI enabled it to be found more easily. This is the first report of a case in which NBI was helpful in locating a fibrin cap of EVs.