Chromo- and magnifying endoscopy for colorectal lesions

It is essential to identify patients with premalignant or early malignant changes during colonoscopy. Thus, curative resection can be offered. At present, endoscopy can be performed with new powerful high-resolution or magnifying endoscopes. Comparably to the rapid development in chip technology, the optic features of the newly designed endoscopes offer resolutions which allow new mucosal surface details to be seen. In conjunction with chromoendoscopy, the newly discovered tool video endoscopy is much easier and more impressive than with conventional fibre optics. This review summarizes the value of magnifying endoscopy in the lower gastrointestinal tract and focuses on colorectal lesions.     

Endoscopic detection of early lower gastrointestinal cancer

The prognosis for patients with malignancies of the lower gastrointestinal tract is strictly dependent on early detection of premalignant and malignant lesions. What should an ideal screening and surveillance colonoscopy be able to accomplish? The technique should allow detection of large but also discrete mucosal alterations. Ideally, endoscopic discrimination between neoplastic and non-neoplastic lesions would be possible during the ongoing procedure. At present, endoscopy can be performed with powerful new endoscopes. Comparable to the rapid development in chip technology, the optical features of the newly designed endoscopes offer resolutions, which allow new surface details to be seen. In conjunction with chromoendoscopy, the newly discovered tool video colonoscopy is much easier and more impressive today than with the previously used fibre-optic endoscopes. Recently, new endoscopic technologies such as narrow band imaging, endocytoscopy, or confocal laser endoscopy have allowed the discovery of a whole new world of image details which will surely improve the diagnostic yield in the field of early malignancies. This review summarises newly available technologies and clinical data about the diagnosis of early lower gastrointestinal cancers.     

Technology insight: Laser-scanning confocal microscopy and endocytoscopy for cellular observation of the gastrointestinal tract

Recent advances in endoscopic imaging technology have enabled the visualization of early-stage cancer and its precursors in the gastrointestinal tract. Chromoendoscopy, magnifying endoscopy, endoscopic optical coherent tomography, spectroscopy, and various combinations of these technologies, are all important for the recognition of small and unclear lesions. To observe cancer cells in vivo, two types of ultra-high magnifying endoscope--'laser-scanning confocal endoscopy series' and 'contact endoscopy series'--that have a maximum of more than 1,000x magnifying power have been developed. These endoscopes can generate high-quality images of both living cancer cells and normal cells in the gastrointestinal tract, with a quality comparable to that possible with conventional cytology. These novel imaging technologies may make in vivo histological diagnosis by virtual histology possible.     

Novel endoscopic imaging techniques toward in vivo observation of living cancer cells in the gastrointestinal tract

Recent advances in endoscopic imaging technology have enabled the visualization of cellular-level microstructures of early-stage cancer and its precursors. Chromoendoscopy, magnifying endoscopy, endoscopic optical coherent tomography (EOCT) spectroscopy, and various combinations of these technologies, are all important for the recognition of small and unclear lesions. In order to observe cancer cells in vivo two types of ultra-high magnifying endoscope--'laser-scanning confocal laser-scanning endoscopy series' and 'contact endoscopy series'--that have a maximum of >1,000 times magnifying power have been developed. The use of these endoscopes has allowed the generation of high quality images of both living cancer cells and normal cells in the gastrointestinal tract. In particular, clear images of cells and their nuclei, equivalent to the high quality that is possible with conventional cytology, have been produced. These novel imaging technologies may make in vivo histological diagnosis by virtual histology possible.     

FUTURE PERSPECTIVES OF GASTROINTESTINAL ENDOSCOPY AND JOINT ACADEMIC–INDUSTRIAL RESEARCH FOLLOWING TECHNOLOGICAL INNOVATION IN MEDICAL AND BIOLOGICAL ENGINEERING

Screening surveys conducted to predict the future of gastrointestinal endoscopy, have revealed a tendency towards emphasis on the development of endoscopes of smaller diameters, to reduce the pain and discomfort caused to patients. It appears that the efforts to develop newer endoscopes with a focus on further reducing the diameter of the tip of the endoscopes, while preserving the visualizing and manipulating capabilities of endoscopes, are moving towards development of wireless capsule endoscopes. Regarding improvement in the diagnostic capabilities of endoscopes, it is expected that high‐definition (HD)‐TV technology‐compatible endoscopy systems and so on, will be developed in the near future, with the improved resolution of images and improved image analysis systems, accompanied by the development of new endoscope‐linked devices, such as endoscopic ultrasonography, a fluorescent endoscope, and an ultra‐magnifying endoscope. These developments may eventually lead to the age of ‘bioendoscopy’, in which endoscopes would be used for not only morphological diagnosis, like conventional endoscopes, but also for evaluation of the pathophysiology of individual diseases through combining cell‐level diagnosis with functional diagnosis using an ultra‐magnifying endoscope. This paper will also summarize the current status and problems pertaining to joint academic‐industrial research for the development of new diagnostic imaging devices from an international perspective, placing emphasis on the ideal mode of academic–industry collaboration, improvements in education and personnel development, strengthening of collaboration among the medical, engineering and pharmaceutical fields, and promotion of clinical trials on new medical devices.     

MAGNIFYING ENDOSCOPIC OBSERVATION OF THE UPPER GASTROINTESTINAL TRACT

Recent advances in technology enable us to obtain more detailed information during endoscopic procedures. Diagnosis of the pit pattern or microvascular architecture allow the earlier detection of neoplastic lesions in the gastrointestinal tract. These advances have led to the enhanced selection of appropriate treatments. Cancers that are discovered at an early stage can be treated by mucosal resection, whereas advanced cancers are treated with surgery. Recently, some groups have tried to acquire direct in vivo histological images of gastrointestinal mucosa (virtual histology or optical biopsy). Now optical coherence tomography (OCT), confocal laser endoscopy and endo‐cytoscopy systems enable this conception. However, none of these techniques has been proven, although some investigators have been able to use them to enhance cancer detection, and have reported the usefulness of these techniques. The present review assesses the strengths and weaknesses of these technologies, and describes the magnifying observations of the upper gastrointestinal tract using magnifying endoscopy equipment available on the market as well as newly developed endo‐cytoscopy systems. Published and unpublished data for this review were identified by searches of MEDLINE, Register of Cancer Trials: National Cancer Institute ( http://cancertrials.nci.nih.gov/ ) and references from relevant articles. We also contacted researchers. The authors’ own database of references was also used. The search items were as follows: magnifying endoscopy, endo‐cytoscopy system, confocal endoscopy, optical coherence tomography, contact endoscopy, esophageal cancer, Barrett’s esophagus, Barrett’s esophageal cancer, gastric cancer, colon cancer, chromoendoscopy, methylene blue etc.     

Usefulness of magnifying endoscopic evaluation of the terminal ileum for a patient with graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

The gastrointestinal tract is one of the common targets of acute graft-versus-host disease (GVHD), but accurate diagnosis is difficult because of the nonspecific nature of complicated diseases and the lack of diagnostic findings by conventional endoscopy. Recently, a magnifying endoscope has been developed and used for examining microstructures of the mucosa. Herein, we report the first use of a magnifying endoscope for a patient with gastrointestinal (GI) GVHD. Magnified endoscopic findings of atrophic and coalescent villi of the terminal ileum reflect histological findings of GVHD. Magnifying endoscopy of the terminal ileum may be useful for early detection and follow-up of GI GVHD.     

Improving visualization techniques by narrow band imaging and magnification endoscopy

Endoscopy plays an important role in the early detection of gastrointestinal tract neoplasms. Using conventional white light or dye-based image enhanced endoscopy, it has been difficult to assess pre-malignant and early neoplastic lesions precisely. However, narrow band imaging (NBI) dramatically improves the detection of these lesions, particularly in combination with magnifying endoscopy. This allows the endoscopist to accomplish accurate diagnosis. Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsy, improved and more appropriate treatment, and thereby contribute to optimal quality of life and patient survival.     

上消化道肿瘤高危人群放大内镜检查中西部专家意见

食管癌和胃癌是我国中西部地区常见的恶性肿瘤之一,严重威胁中西部地区居民生命健康。近年来,放大内镜技术在早期食管癌和早期胃癌筛查和诊断中已受到广泛使用,国内尤其是中西部众多专家通过多次讨论,并结合上消化道早期癌放大内镜诊治的最新研究进展,制定了更适合我国的上消化道肿瘤高危人群放大内镜检查中西部专家意见,以期进一步提高中西部地区上消化道早期癌的检出率,并推动放大内镜的规范应用。     

Narrow band imaging with magnification for the diagnosis of lesions in the upper gastrointestinal tract

Endoscopy plays an important role in the diagnosis and management of gastrointestinal(GI)tract disorders.Chromoendoscopy has proven to be superior to white light endoscopy for early detection of various GI lesions.This has however been fraught with problems.The use of color stains,time taken to achieve an effect and the learning curve associated with the technique has been some of the pitfalls.Narrow band imaging(NBI)particularly in combination with magnifying endoscopy may allow the endoscopist to accomplish a fairly accurate diagnosis with good histological correlation similar to results achieved with chromoendoscopy.Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsies and could ultimately prove to be cost effective.Various studies have been done demonstrating the utility of this novel technology.This article will review the impact of NBI in the diagnosis of upper gastrointestinal tract disorders.     

USEFULNESS OF MAGNIFYING ENDOSCOPY IN UPPER GASTROINTESTINAL TRACT: HISTORY AND RECENT STUDIES

Although clinical trials using magnifying optical endoscopy have been reported, magnifying endoscopies have been remarkably developed in the period of electronic endoscopy. Magnifying electronic endoscopies with 80 or 100‐fold magnification are used for routine endoscopic examination of upper gastrointestinal tract in Japan. Magnifying endoscopy is used to visualize the microstructure and microvascular architecture of gastrointestinal surface mucosa. Microsurface structure of the mucosa includes normal structure, changed structure by inflammation and biological response, and tumor‐specific structure. Microvascular architecture includes normal vascular system and tumor microvessels. Magnifying endoscopy is starting to play an important role in diagnosis of any upper gastrointestinal diseases by assessment of magnified observation. Magnifying endoscopy holds a great deal of promise in the near future because magnifying endoscopic observation is approaching optical biopsy.     

Magnifying endoscopy in upper gastrointestinal tract]

For the diagnosis of upper gastrointestinal (GI) lesions, magnification method is usually used in conjunction with chromoscopy, enabling the endoscopist to view subtle mucosal patterns in exquisite detail. Recently published datas have shown that magnifying endoscopy might be a valuable adjunct for the diagnosis, detection, and characterization of inflammatory and neoplastic lesions of the upper GI tract. It is also proven to be an useful surveillance protocol in identifying dysplastic epithelium or early cancer within a segment of Barrett's esophagus. Possible indications for magnifying endoscopy in upper GI tract include screening and surveillance of Barrett's esophagus, defining the extent of esophageal and gastric adenocarcinoma, detecting synchronous/metachronous gastric and esophageal cancers, diagnosing Helicobacter pylori infection, and recognizing minimal mucosal changes in gastroesophageal reflux disease. By grading the quality of evidence for the currently published trials, it is clear that the majority are case series, case reports, and/or observational studies without randomization, control, or blinding. Moreover, other evidence-based criteria such as independent, blind comparisons of magnifying endoscopy with a standard method which evaluates this technology in an appropriate spectrum of patients to whom the test may be applicable, and standardizing methodology would be crucial before magnifying endoscopy becomes a standard procedure in clinical practice. In the future, a uniform classification system for staining and magnifying patterns should be devised and observer agreement should be tested. Futher studies then could be performed based upon consistent, validated, and standardized terminologies and criteria.     

放大内镜在胃部疾病诊断中的应用

放大内镜在消化道疾病尤其胃癌及癌前病变的诊断方面有着独特优势,并能指导活检,避免不必要的活检创伤,有着普通内镜所不能比拟的优势.本文对近年来放大内镜在胃部疾患的应用进展作一综述,同时结合临床操作体会,总结放大内镜的操作要领.     

Perspectives of chromo and magnifying endoscopy: how, how much, when, and whom should we stain?

The goal of every routine endoscopy in the gut is the early diagnosis of malignant and premalignant changes of the mucosa. Chromo- and magnifying endoscopes are exciting new tools and offer detailed analysis of the colonic mucosal surface and pit pattern architecture. This review summarizes recent advances in endoscopic characterization of colorectal lesions using magnification endoscopy and chromoendoscopy. Surface analysis of the colon using chromoendoscopy allows a prediction between non-neoplastic and neoplastic lesions with high specificity. The precise delineation of the borders and a more detailed macroscopic analysis of the lesions are further advantages. In particular, flat adenomas and early depressed cancers are now more frequently recognized in western countries suggesting that significant lesions were overlooked by conventional endoscopy in the past. Furthermore, chromoendoscopy can be used in a targeted fashion to screen for sporadic adenomas. Finally, in surveillance colonoscopy, patients with long-standing ulcerative colitis have a valuable benefit if targeted biopsies are performed to detect intraepithelial neoplasias after pan-chromoendoscopy with methylene blue. Although there is a long learning curve, chromoendoscopy should thus belong to every endoscopists armamentarium. However, detailed knowledge about the technique, dyes, and specific staining patterns are mandatory before the yield of screening or surveillance colonoscopy can be increased. The new detailed images seen with magnifying chromoendoscopy are unequivocally the beginning of a new era where new optical developments will allow a unique look on cellular structures.     

Endoscopic microanatomy of the normal gastrointestinal mucosa with narrow band technology and magnification

The development of high-definition endoscopes with optical zoom, along with the use of the digital chromoendoscopy and staining, has given endoscopists the possibility to study the microanatomy of the gastrointestinal mucosa in vivo. The recognition of the changes in the microstructure of the surface and microvascular architecture such as those that occur in neoplastic lesions allow us to characterize these lesions in order to decide on the best course of clinical action. The current greater availability of endoscopes with optical zoom in western countries has allowed the use of this technology in routine clinical practice to spread. In this article we review the basic concepts of magnifying endoscopy and the normal endoscopic microanatomy of the oesophageal, gastric, duodenal, ileal and colonic mucosa.     

Documento de posicionamiento de la AEG,la SEED y la SEAP sobre calidad de la endoscopia digestiva alta para la detección y vigilancia de las lesiones precursoras de cáncer gástrico

This position paper, sponsored by the Asociación Española de Gastroenterología [Spanish Association of Gastroenterology], the Sociedad Española de Endoscopia Digestiva [Spanish Gastrointestinal Endoscopy Society] and the Sociedad Española de Anatomía Patológica [Spanish Anatomical Pathology Society], aims to establish recommendations for performing an high quality upper gastrointestinal endoscopy for the screening of gastric cancer precursor lesions (GCPL) in low-incidence populations, such as the Spanish population. To establish the quality of the evidence and the levels of recommendation, we used the methodology based on the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). We obtained a consensus among experts using a Delphi method. The document evaluates different measures to improve the quality of upper gastrointestinal endoscopy in this setting and makes recommendations on how to evaluate and treat the identified lesions. We recommend that upper gastrointestinal endoscopy for surveillance of GCPL should be performed by endoscopists with adequate training, administering oral premedication and use of sedation. To improve the identification of GCPL, we recommend the use of high definition endoscopes and conventional or digital chromoendoscopy and, for biopsies, NBI should be used to target the most suspicious areas of intestinal metaplasia. Regarding the evaluation of visible lesions, the risk of submucosal invasion should be evaluated with magnifying endoscopes and endoscopic ultrasound should be reserved for those with suspected deep invasion. In lesions amenable to endoscopic resection, submucosal endoscopic dissection is considered the technique of choice.     

Guidelines for standardizing cleansing and disinfection of gastrointestinal endoscopes

As part of the activities toward standardizing endoscopy procedures, the Japan Gastroenterological Endoscopy Society has prepared guidelines for cleansing and disinfection of gastrointestinal endoscopes. The environment of gastrointestinal endoscopy differs between Japan and advanced Western countries. In advanced Western countries, gastrointestinal endoscopy is performed almost exclusively at specialized facilities, where strict provisions are observed for cleansing and disinfecting endoscopes. In Japan, however, gastrointestinal endoscopy is performed even in small clinics, and the annual number of gastrointestinal endoscopy cases is enormous. In addition, the method for cleansing and disinfecting endoscopes differs among hospitals. Although there is a distinct lack of evidence for how gastrointestinal endoscopes are cleaned and disinfected, it is necessary to standardize the method for doing so to advance the field of endoscopic medicine.     

What can we see with the endoscope? Present status and future perspectives

The present status and future perspectives in new technologies of image processing and analysis, infrared ray endoscopy and autofluorescence endoscopy for gastrointestinal cancer are presented in this paper. Spectroscopic measurements using an endoscopic spectroscopic system are useful for distinguishing between benign and malignant gastric mucosal lesions, and the histological classification of early gastric cancer is possible on the basis of the spectroscopic characteristics. It is expected that adaptive hemoglobin index color enhancement would be useful for the qualitative diagnosis of early gastric cancer and for detecting specialized columnar epithelium in Barrett’s esophagus in combination with magnifying endoscopy. Our preliminary experience suggess that magnifying endoscopy with a narrow‐band imaging system could predict the histological characteristics of gastric cancerous lesions with high accuracy. Recent studies revealed that infrared ray electronic endoscopy is very useful for diagnosing the depth of invasion in early gastric cancer. In addition, it is evident that specific antibodies tagged with the indocyanine green derivative can label cancer cells and can generate a fluorescent signal strong enough to detect small cancers using an infrared fluorescence endoscope. The future development and evaluation of autofluorescence endoscopy are discussed, and we propose a modification to the system, including the excitation lights.     

Endoscopic therapy of lower gastrointestinal cancer

Since the 1960's, endoscopy has revolutionised the practice of gastroenterology. Although initially diagnostic, endoscopy is now playing an increasingly therapeutic role. There are many reasons to believe that therapeutic endoscopy will shape the practice of gastroenterology further in the future. Only a few years ago we relied on low-resolution fibreoptic endoscopes. Nowadays even standard equipment allows the mucosa to be scrutinised in great detail. Dedicated training in endoscopy together with attention to quality indicators such as polyp detection and caecal intubation rates will ensure that fewer early gastrointestinal cancers are missed in the future. Open access endoscopy and screening programs are being introduced in many Western countries which will also lead to more lesions being detected in their early stages. This chapter discusses the main issues surrounding the endoscopic therapy of lower gastrointestinal cancers.     

放大结合窄带成像在上消化道内镜检查中指导靶向活检的价值

目的探讨放大内镜（magnifying endoscopy,ME）结合窄带成像（narrow—band imaging,NBI）在上消化道胃镜检查中指导靶向活检的价值。方法筛选普通白光胃镜检查活检提示存在低级别上皮内瘤变的患者或直径大于2．0cm的胃溃疡患者,共200例,随机分成2组,2—4周复查胃镜。普通白光胃镜组：普通白光胃镜观察后局部活检。ME—NBI组：根据放大胃镜下表现,在病变最严重部位靶向活检。分析普通胃镜活检结果与ME—NBI靶向活检结果与最终病理诊断结果的关系。结果200例患者中,3例患者失访,共完成197例。普通白光胃镜组100例,其中食管病变23例,胃病变77例。ME—NBI组97例,其中食管病变19例,胃病变78例。ME-NBI组平均每例活检数（2．95块）与普通胃镜组（4．56块）相比差异具有统计学意义（P〈0．001）。与最终病理结果符合率：ME—NBI90．7％（88／97）,普通胃镜71．0％（71／100）。两组间差异具有统计学意义（P〈0．01）。结论ME—NBI技术操作简便,可清晰观察病灶微细结构,有助于提高早期上消化道肿瘤的靶向活检准确率,在常规胃镜检查中发现可疑病灶后,可使用ME．NBI观察,指导靶向活检。