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

Technical Advances in Endoscopic Resection Techniques for Lower GI Malignancies

Background

The management of bulky neoplastic lesions in the digestive tract has historically been a surgical pursuit. With advancements in endoscopic techniques, particularly endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), a paradigm shift toward organ preservation has been initiated. These endoscopic methods, developed incrementally since the 1980s, have progressively enabled curative management of lesions with minimal morbidity, challenging the previously unchallenged domain of surgery.

Summary

This review traces the evolution of endoscopic resection from snare polypectomy and EMR to sophisticated ESD, highlighting the technological innovations that have expanded the scope of endoscopic resection. It discusses the intricacies of various EMR techniques like underwater EMR, anchoring EMR, and hybrid EMR, alongside traction-assisted methods and the use of viscous solutions for submucosal injection. Additionally, the manuscript delves into the advancements in ESD, emphasizing traction strategies, knife technology, and the optimization of endoscopes. The benefits of these advancements are weighed against the challenges in anatomopathological interpretation posed by piecemeal resections.

Key Messages

The continuous amelioration of endoscopic resection techniques has significantly improved the outcomes of digestive tract lesion management, particularly in achieving R0 resections and reducing recurrence rates. These advancements represent a monumental step toward minimizing the invasiveness of lesion management. However, despite the progress, the necessity for early follow-up post-EMR remains due to the non-negligible recurrence rates, underscoring the need for a rigorous postoperative surveillance regimen. Furthermore, our review suggests that while ESD has transformed the therapeutic landscape, its widespread adoption hinges on further simplification, safety enhancement, and acceleration of the procedure, possibly through innovations like adaptive traction devices.

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.

Near infrared imaging system for preventing blood vision obstruction in endoscopy

Spinal endoscopy procedure is commonly used in the diagnosis and treatment of various health problems and is effective. Bleeding is one of the most common complications of spinal endoscopy procedures. Blood vision obstruction (BVO), that is, obstruction of the endoscopic camera lens caused by the accumulation of blood in the surgical field, is a serious problem in endoscopic procedures. This study presents what we believe to be a new approach to addressing BVO with external multispectral imaging. The study was completed using a BVO simulation model, and the results reveal that this technology can be used to effectively overcome BVO and provide clear images of the anatomy, enabling more effective diagnosis and treatment. This technique may enable improvement of the outcomes of endoscopic procedures and could have far-reaching implications in the field of endoscopy.

Red dichromatic imaging improves visibility of bleeding during gastric endoscopic submucosal dissection

Bleeding frequently occurs during gastric endoscopic submucosal dissection (ESD) and bleeding points are sometimes difficult to detect. Red dichromatic imaging (RDI) was recently developed to improve the visibility of bleeding. Our study aimed at examining the efficacy of RDI in improving the visibility of bleeding during gastric ESD. We retrospectively evaluated the visibility score and color difference of bleeding spot during gastric ESD during September 2020-January 2021. The visibility score was evaluated as four numeric values by operators, and the color difference between the bleeding spot and surroundings was evaluated using RDI and white light imaging (WLI). A further analysis to evaluate bleeding characteristics was performed to evaluate the possible beneficial effects of RDI. Twenty patients with a total of 85 bleedings were analyzed. The mean visibility score in RDI was significantly higher than that in WLI (3.69 ± 0.60 vs 3.20 ± 0.84, p < 0.01). The color difference with RDI was also significantly higher than that with WLI (19.51 ± 15.18 vs 14.80 ± 7.41, p < 0.01). Furthermore, in the bleedings with a higher visibility score in RDI, the color difference in RDI was significantly higher than that in WLI (23.99 ± 19.29 vs 14.33 ± 7.08, p < 0.01). The multivariate analysis of visibility scores revealed that submergence of bleeding points was independently associated with the superiority of RDI (odds ratio 10.35, 95% confidence interval: 2.76-38.81, p < 0.01). Our study demonstrates that RDI can improve the visibility of bleeding during gastric ESD.

Efficacy of using red dichromatic imaging throughout endoscopic submucosal dissection procedure

BACKGROUND

Management of bleeding during endoscopic submucosal dissection (ESD) is critical. Red Dichromatic Imaging (RDI), a novel image-enhanced endoscopy technology, has been reported to improve the visibility of deep vessels and bleeding source compared to white light imaging (WLI). We hypothesized that using RDI during the entire cutting process (full time RDI ESD: FTR-ESD), higher R0 resection rate, shorter procedure time and fewer complications could be achieved. Therefore, the aims of the present study were to investigate the efficacy and safety of FTR-ESD.

METHODS

This retrospective observational study included a total of 82 consecutive patients who underwent ESD by a single expert endoscopist for 40 esophageal, 17 gastric and 25 colorectal cancers at our institution from January 2018 to March 2021. The clinicopathological data were collected from patients' medical records and the treatment outcomes were analyzed according to the treatment phase (early; 57 WLI-ESD and late; 25 FTR-ESD).

RESULTS

The median of the greatest diameter of resected specimen was 40.0 mm. The median procedure time was relatively shorter in the FTR-ESD group (35 min) than in the WLI-ESD group (40 min), but the difference was not statistically significant (p = 0.34). The median dissection speed in the FTR-ESD group (27.23 mm²/min) was significantly faster than that in the WLI-ESD group (20.94 mm²/min) (p = 0.025). The dissection speed was not different among different organs. A multivariate analysis revealed that tumor size (more than 30 mm) and FTR-ESD were significant independent factors contributing to faster dissection speed (p < 0.05). There were no significant differences in the rates of en bloc resection, HM0, VM0 or occurrence of adverse events between WLI-ESD and FTR-ESD.

CONCLUSIONS

FTR-ESD significantly increases the dissection speed compared to WLI-ESD. FTR-ESD can be performed safely and therapeutic outcomes in FTR-ESD are comparable with WLI-ESD. A further multicenter prospective study is warranted to confirm our results.

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.

Novel image enhancement technology that helps find bleeding points during endoscopic submucosal dissection of gastric neoplasms

BACKGROUND AND AIM

The management of bleeding during endoscopic submucosal dissection (ESD) is critical and related to the procedure time. We collaborated on a new image enhancement algorithm with parameter optimization for clinical use being developed by FUJIFILM Co. and processed white light image data offline to evaluate the effectiveness of this technology. This study aims to evaluate the clinical usefulness of this technology.

METHODS

Eighteen video scenes of bleeding points from five gastric ESDs were selected and processed by the new image enhancement algorithm. The time until a bleeding point was found, visibility of a bleeding point, and color abnormality of the submucosal layer were evaluated by ESD experts, ESD trainees, and endoscopy trainees. The color differences between the bleeding point and the surroundings in CIE-L*a*b* color space were calculated in the original and enhanced images.

RESULTS

The time until a bleeding point was found in the enhanced videos was significantly shorter than that in the original videos (11.10 s vs 13.85 s) (P = 0.017). On a 5-point (-2 to +2) Likert scale of visibility, the enhanced image was slightly superior to the original (+0.45), and the appearance of the submucosa was comparable between images (+0.14). The color difference among the bleeding areas on the enhanced images was significantly larger than that on the original images (10.93 vs 8.36).

CONCLUSION

This novel image enhancement algorithm emphasizes the color difference between a bleeding point and the surrounding area, which would help find bleeding points faster during ESD for the less experienced endoscopists.

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.

Endoscopic treatment for early gastric cancer

Background: In Korea, the number of screening endoscopies to detect early stage gastric neoplasms has increased exponentially following the active implementation of the National Cancer Screening Program.Current Concepts: Endoscopic treatment, including endoscopic mucosal resection and endoscopic submucosal dissection, is recognized as a minimally invasive treatment method with low morbidity and mortality for gastric dysplasia or early gastric cancer. Owing to improvement in the detection of early gastric cancer and advances in techniques, cases of endoscopic resection have increased and indications have been expanded. Endoscopic resection can preserve gastric function with excellent maintenance of the patient’s quality of life, and previous studies have shown better long-term follow-up outcomes compared to those with surgery. However, the fundamental limitation of endoscopic procedures is that gastric lymph-node dissection is not possible using endoscopic resection.Discussion and Conclusion: Although the usefulness of endoscopic resection is proven for tumors with a very low risk of lymph-node metastasis, follow-up examination using endoscopy and computed tomography should be performed for at least 5 years after curative resection of early gastric cancer.

Utility of red dichromatic imaging for identifying the bleeding point in endoscopic hemostasis of colonic diverticular bleeding

Video 1Endoscopic hemostasis of colonic diverticular bleeding using red dichromatic imaging to identify the bleeding point.

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.

Clinical usefulness of red dichromatic imaging in hemostatic treatment during endoscopic submucosal dissection: First report from a multicenter, open-label, randomized controlled trial

OBJECTIVES

To verify the efficacy and safety of red dichromatic imaging (RDI) in hemostatic procedures during endoscopic submucosal dissection (ESD).

METHODS

This is a multicenter randomized controlled trial of 404 patients who underwent ESD of the esophagus, stomach, colorectum. Patients who received hemostatic treatments by RDI during ESD were defined as the RDI group (n = 204), and those who received hemostatic treatments by white light imaging (WLI) were defined as the WLI group (n = 200). The primary endpoint was a shortening of the hemostasis time. The secondary endpoints were a reduction of the psychological stress experienced by the endoscopist during the hemostatic treatment, a shortened treatment time, and a non-inferior perforation rate, in RDI versus WLI.

RESULTS

The mean hemostasis time in RDI (n = 860) was not significantly shorter than that in WLI (n = 1049) (62.3 ± 108.1 vs. 56.2 ± 74.6 s; P = 0.921). The median hemostasis time was significantly longer in RDI than in WLI (36.0 [18.0-71.0] vs. 28.0 [14.0-66.0] s; P = 0.001) in a sensitivity analysis. The psychological stress was significantly lower in RDI than in WLI (1.71 ± 0.935 vs. 2.03 ± 1.038; P < 0.001). There was no significant difference in the ESD treatment time between RDI (n = 161) and WLI (n = 168) (58.0 [35.0-86.0] vs. 60.0 [38.0-88.5] min; P = 0.855). Four perforations were observed, but none of them took place during the hemostatic treatment.

CONCLUSIONS

Hemostatic treatment using RDI does not shorten the hemostasis time. RDI, however, is safe to use for hemostatic procedures and reduces the psychological stress experienced by endoscopists when they perform hemostatic treatment during ESD. UMIN000025134.

Editors' Choice of Noteworthy Clinical Endoscopy Publications in the First Decade

This is a special review to celebrate the 10^th anniversary of Clinical Endoscopy. Each deputy editor has selected articles from one’s subspecialty that are significant in terms of the number of downloads, citations, and clinical importance. The articles included original articles, review articles, systematic reviews, and meta-analyses.

Visibility of the bleeding point in acute rectal hemorrhagic ulcer using red dichromatic imaging: A case report

BACKGROUND

Red dichromatic imaging (RDI) is a novel image-enhanced endoscopy expected to improve the visibility of the bleeding point. However, it has not been thoroughly investigated.

CASE SUMMARY

A 91-year-old man developed a sudden massive hematochezia and underwent emergent colonoscopy. An ulcer with pulsatile bleeding was found on the lower rectum. Due to massive bleeding, the exact location of the bleeding point was not easy to detect with white light imaging (WLI). Upon switching to RDI, the bleeding point appeared in deeper yellow compared to the surrounding blood. Thus, RDI enabled us for easier recognition of the bleeding point, and hemostasis was achieved successfully. Furthermore, we reviewed endoscopic images and evaluated the color difference between the bleeding point and surrounding blood for WLI and RDI. In our case, the color difference of RDI was greater than that of WLI (9. 75 vs 6. 61), and RDI showed a better distinguished bleeding point from the surrounding blood.

CONCLUSION

RDI may improve visualization of the bleeding point by providing better contrast in color difference relative to surrounding blood.

Fundamentals, Diagnostic Capabilities and Perspective of Narrow Band Imaging for Early Gastric Cancer

The development of image-enhanced endoscopy has dramatically improved the qualitative and quantitative diagnosis of gastrointestinal tumors. In particular, narrow band imaging (NBI) has been widely accepted by endoscopists around the world in their daily practice. In 2009, Yao et al. proposed vessel plus surface (VS) classification, a diagnostic algorithm for early gastric cancer using magnifying endoscopy with NBI (ME-NBI), and in 2016, Muto et al. proposed a magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G) based on VS classification. In addition, the usefulness of ME-NBI in the differential diagnosis of gastric cancer from gastritis, diagnosis of lesion extent, inference of histopathological type, and diagnosis of depth has also been investigated. In this paper, we narrative review the basic principles, current status, and future prospects of NBI.

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

Video 1Red dichromatic imaging in peroral endoscopic myotomy.

Photoacoustic endoscopy: A progress review

Endoscopy has been widely used in biomedical imaging and integrated with various optical and acoustic imaging modalities. Photoacoustic imaging (PAI), one of the fastest growing biomedical imaging modalities, is a noninvasive and nonionizing method that owns rich optical contrast, deep acoustic penetration depth, multiscale and multiparametric imaging capability. Hence, it is preferred to miniaturize the volume of PAI and develop an emerged endoscopic imaging modality referred to as photoacoustic endoscopy (PAE). It has been developed for more than one decade since the first report of PAE. Unfortunately, until now, there is no mature photoacoustic endoscopic technique recognized in clinic due to various technical limitations. To address this concern, recent development of new scanning mechanisms, adoption of novel optical/acoustic devices, utilization of superior computation methods and exploration of multimodality strategies have significantly promoted the progress of PAE toward clinic. In this review, we comprehensively reviewed recent progresses in single- and multimodality PAE with new physics, mechanisms and strategies to achieve practical devices for potential applicable scenarios including esophageal, gastrointestinal, urogenital and intravascular imaging. We ended this review with challenges and prospects for future development of PAE.

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.).