Magnifying chromoendoscopy for the detection of premalignant gastrointestinal lesions

The prognosis for patients with malignancies of the gastrointestinal tract is strictly dependent on the early detection of premalignant and malignant lesions. At present, endoscopy can be performed with new, powerful high-resolution or magnifying endoscopes. Comparable to the rapid development in chip technology, the optic features of the newly designed endoscopes offer resolutions that allow new mucosal surface details to be seen. In conjunction with chromoendoscopy, the newly discovered tool of video endoscopy is much easier to use and more impressive than previously used fibreoptic endoscopy. This review summarises the value of magnifying endoscopy in the upper and lower gastrointestinal tract and focuses on gastroesophageal reflux disease and early gastric and colorectal cancer.     

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.     

New aspects of modern endoscopy

The prognosis for patients with malignancies of the ga-strointestinal-tract is strictly dependent on early detec-tion of premalignant and malignant lesions. However, small, flat or depressed neoplastic lesions remain dif-ficult to detect with these technologies thereby limiting their value for polyp and cancer screening. At the same time computer and chip technologies have undergone major technological changes which have greatly im-proved endoscopic diagnostic investigation. New imag-ing modalities and techniques are very notable aspects of modern endoscopy. Chromoendoscopy or filter-aided colonoscopy(virtual chromoendoscopy) with high defi-nition endoscopes is able to enhance the detection and characterization of lesions. Finally, confocal laser en-domicroscopy provides histological confirmation of the presence of neoplastic changes. The developing tech-niques around colonoscopy such as the retro-viewing colonoscope, the balloon-colonoscope or the 330-de-grees-viewing colonoscope try to enhance the efficacy by reducing the adenoma miss rate in right-sided, non-polypoid lesions. Colon capsule endoscopy is limited to identifying cancer and not necessarily small adenomas. Preliminary attempts have been made to introduce this technique in clinical routine.     

Chromoendoscopy

Accurate detection of premalignant lesions and early cancers in the gastrointestinal tract is essential for curative endoscopic or surgical therapy, because prognosis of the affected patients is closely related to the size and stage of the neoplastic lesion. Recently, it has emerged new endoscopic devices that allow even cellular images in vivo during an endoscopic procedure. These technologies will change and improve endoscopic diagnosis. The combination and integration of different technologies in a multifunctional endoscope will offer new optical features in GI endoscopy. Cytoendoscopy will characterize the surface architecture, confocal laser endomicroscopy will immediately clarify the nature of the lesions by in vivo histology of the mucosal layer, and optical coherence tomography will accurately grade the invasion depth. It will need some additional time before this scenario comes true. Endoscopy will become more complex due to the new visible details. Education and training will play an important future role in GI endoscopy. However, it is not possible to use these novel technologies without before learn to identify early GI cancers lesions. Meanwhile these technologies are perfectionated and we overcome the learning curve to identify early GI lesions, chromoendoscopy will continue to be a safe, easy and inexpensive method.     

Chromoendoscopy and other novel imaging techniques

The newly developed high-resolution and magnification endoscopes offer features that allow more and new mucosal details to be seen. They are commonly used in conjunction with chromoendoscopy. The analysis of mucosal surface details is beginning to resemble histologic examination. More accurate recognition of small flat and depressed neoplastic lesions is possible. Endoscopic prediction of neoplastic and nonneoplastic tissue is possible by analysis of surface architecture of the mucosa, which influences the endoscopic management. For the diagnosis of flat adenomas, chromoendoscopy should be a part of the endoscopist's armamentarium. In inflammatory bowel disease, chromoendoscopy can be used for patients with long-standing UC to unmask flat intraepithelial neoplasia and is likely to become the new standard method for surveillance colonoscopy in the near future. The new detailed images seen with magnifying chromoendoscopy are the beginning of a new era in which advances in optical development, such as confocal endomicroscopy, allow a unique look at detailed cellular structures.     

High technology imaging in digestive endoscopy

A thorough endoscopic visualization of the digestive mucosa is essential for reaching an accurate diagnosis and to treat the different lesions. Standard white light endoscopes permit a good mucosa examination but, nowadays, the introduction of powerful endoscopic instrumentations increased ability to analyze the fi nest details. By applying dyes and zoom-magnifi cation endoscopy further architectural detail of the mucosa can be elucidated. New computed virtual chromoendoscopy have further enhanced optical capabilities for the evaluation of submucosal vascolar pattern. Recently, confocal endomicroscopy and endocytoscopy were proposed for the study of ultrastructural mucosa details. Because of the technological contents of powerful instrumentation, a good knowledge of implemented technologies is mandatory for the endoscopist, nowadays. Nevertheless, there is a big confusion about this topic. We will try to explain these technologies and to clarify this terminology.     

Photodiagnostic techniques for the endoscopic detection of premalignant gastrointestinal lesions

Considerable attention is given to the clinical diagnosis of gastrointestinal (GI) malignancies as they remain the second leading cause of cancer‐associated deaths in developed countries. Detection and intervention at an early stage of preneoplastic development significantly improve patient survival. High‐risk assessment of asymptomatic patients is currently performed by strict endoscopic surveillance biopsy protocols aimed at early detection of dysplasia and malignancy. However, poor sensitivity associated with frequent surveillance programs incorporating conventional screening tools, such as white light endoscopy and multiple random biopsy, is a significant limitation. Recent advances in biomedical optics are illuminating new ways to detect premalignant lesions of the GI tract with endoscopy. The present review presents a summary report on the newest developments in modern GI endoscopy, which are based on novel optical endoscopic techniques: fluorescence endoscopic imaging and spectroscopy, Raman spectroscopy, light scattering spectroscopy, optical coherence tomography, chromoendoscopy, confocal fluorescence endoscopy and immunofluorescence endoscopy. Relying on the interaction of light with tissue, these ‘state‐of‐the‐art’ techniques potentially offer an improved strategy for diagnosis of early mucosal lesions by facilitating targeted excisional biopsies. Furthermore, the prospects of real‐time ‘optical biopsy’ and improved staging of lesions may significantly enhance the endoscopist's ability to detect subtle preneoplastic mucosal changes and lead to curative endoscopic ablation of these lesions. Such advancements within this specialty will be rewarded in the long term with improved patient survival and quality of life.     

PREFACE

The present paper discusses where endoscopic diagnosis and treatment will be in 10 years. The demand for gastroenterologist services is growing, driven partly by the aging population and the popularity of screening colonoscopy. Hopefully, along with better genetic and fecal markers, it will allow colonoscopy to be used much more efficiently in patients who really need it. Innovations in reduction of pressure on patients by decreasing the diameter of the electron endoscope, particularly the transnasal endoscope, are continued, in parallel with the development and research of capsule endoscopy as a tentative measure. There will be issues regarding will perform the screening test, and how the medical expenses should be established. In contrast, highly precise imaging techniques are progressing. The most important theme of endoscopic medicine is the further prevalence of and development of therapeutic endoscopy in such situation as gastroesophageal reflux disease, obesity, hemostasis, luminal stenosis, endoscopic submucosal dissection for early gastrointestinal cancer, stenting, endoscopic shincterotomy and natural orifice translumenal endoscopic surgery for pancreatic biliary or other diseases. In addition, the field of gastroenterology and gastrointestinal endoscopy will need to evolve into one of the digestive health sciences, a new multidisciplinary specialty. It will be required to have a department of digestive diseases integrating all specialists in this field.     

New optical technologies for earlier endoscopic diagnosis of premalignant gastrointestinal lesions

Gastrointestinal malignancies continue to be the second leading cause of cancer-related deaths in the developed world. The early detection and treatment of gastrointestinal preneoplasms has been demonstrated to significantly improve patient survival. Conventional screening tools include standard white light endoscopy (WLE) and frequent surveillance with biopsy. Well-defined endoscopic surveillance biopsy protocols aimed at early detection of dysplasia and malignancy have been undertaken for groups at high risk. Unfortunately, the poor sensitivity associated with WLE is a significant limitation. In this regard, major efforts continue in the development and evaluation of alternative diagnostic techniques. This review will focus on notable developments made at the forefront of research in modern gastrointestinal endoscopy based on novel optical endoscopic modalities, which rely on the interactions of light with tissues. Here we present the 'state - of - the - art' in fluorescence endoscopic imaging and spectroscopy, Raman spectroscopy, optical coherence tomography, light scattering spectroscopy, chromoendoscopy, confocal fluorescence endoscopy, and immunofluorescence endoscopy. These new developments may offer significant improvements in the diagnosis of early lesions by allowing for targeted mucosal excisional biopsies, and perhaps may even provide 'optical biopsies' of equivalent histological accuracy. This enhancement of the endoscopist's ability to detect subtle preneoplastic changes in the gastrointestional mucosa in real time and improved staging of lesions could lead to curative endoscopic ablation of these lesions and, in the long term, improve patient survival and quality of life.     

Non-small-bowel abnormalities identified during small bowel capsule endoscopy

AIM:To investigate the incidence of non-small-bowelabnormalities in patients referred for small bowel capsule endoscopy,this single center study was performed.METHODS:Small bowel capsule endoscopy is an accepted technique to investigate obscure gastrointestinal bleeding.This is defined as bleeding from the digestive tract that persists or recurs without an obviousetiology after a normal gastroduodenoscopy and colonoscopy.Nevertheless,capsule endoscopy sometimesreveals findings outside the small bowel,i.e.,withinreach of conventional endoscopes.In this retrospectivesingle center study,595 patients undergoing capsuleendoscopy between 2003 and 2009 were studied.Theincidence of non-small bowel abnormalities was defined as visible abnormalities detected by capsule endoscopy that are located within reach of conventionalendoscopes.RESULTS:In 595 patients,referred for obscure gastrointestinal bleeding or for suspected Crohn’s disease,abnormalities were found in 306(51.4%).Of these 306patients,85(27.7%)had abnormalities within reach of conventional endoscopes;63 had abnormalities apparently overlooked at previous conventional endoscopies,10 patients had not undergone upper and lower endoscopy prior to capsule endoscopy and 12 had abnormalities that were already known prior to capsule endoscopy.The most common type of missed lesions were vascular lesions(n=47).Non-small-bowel abnormalities were located in the stomach(n=15),proximal small bowel(n=22),terminal ileum(n=21),colon(n=19)or at other or multiple locations(n=8).Ten patients with abnormal findings in the terminal ileum had not undergone examination of the ileum during colonoscopy.CONCLUSION:A significant proportion of patients undergoing small bowel capsule endoscopy had lesions within reach of conventional endoscopes,indicating that capsule endoscopy was unnecessarily performed.     

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.     

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.     

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.     

Recent advances in pediatric gastrointestinal endoscopy: an overview

Introduction: Pediatric gastrointestinal endoscopy has become a fundamental component of health care for infants and children. New imaging technologies and creative extraluminal applications have brought exciting and clinically important benefits to pediatric gastrointestinal endoscopy.

Areas covered: The impact of different new technologies in pediatric endoscopy and focused on improvements in mucosa visualization and the application of new noninvasive tools and procedures to avoid biopsies or surgery are reviewed.

Expert commentary: Enhancement in mucosal visualization and reduction of anesthesia and biopsies are the main goals that guide the endoscopy development in pediatrics. The advent of newer imaging modalities has allowed clinicians to characterize and evaluate subtle mucosal lesions better, while advancements in current endoscopes have created the opportunity to monitor chronic conditions noninvasively. Continued expansion of these modalities seems certain, with increased utilization in pediatric gastroenterology.     

Advanced imaging and therapeutic endoscopy

From the early days of gastrointestinal endoscopy, there has been remarkable progress in imaging technology. High-definition endoscopes are now part of the standard armamentarium and a variety of other advanced imaging modalities jostle for space. However, the objective of each of these remains much the same; the enablement of the endoscopist to accurately characterize early gastrointestinal mucosal lesions, which are beyond the capability of standard devices. The benefit of doing so, may be manifold. First, during surveillance of gastrointestinal malignancy, the endoscopist may choose to eschew random biopsies in favor of targeted ones from areas of suspicious mucosa. Second, early mucosal lesions may be detected, which are typically amenable to endoscopic therapy. The ultimate result is improved clinical outcomes and in many cases, the avoidance of surgery. The goal of this review is to summarize for the reader, the most important technologies in advanced endoscopic imaging and their applicability to clinical practice with emphasis on their functioning, implementation, and effect on therapeutic endoscopy.     

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.     

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.     

CT仿真内镜与电子内镜诊断胃肠道疾病的对照研究

目的对比分析CT仿真内镜(CTVE)与电子内镜对胃肠道疾病的诊断价值。方法对84例可疑胃肠道疾病患者行CTVE检查,同时行电子胃镜或电子结肠镜检查,其中47例经内镜及手术病理证实,24例经内镜下病理活检确定诊断。结果84例中胃癌17例,结直肠癌48例,以手术及病理确诊为标准,内镜和CTVE对肿瘤的诊断符合率均为98.46%(64/65),CTVE还检出胃肠外转移病灶29例;内镜下检出结直肠息肉20例,其中CTVE检出15例,符合率为75%;CTVE对炎症性肠病及溃疡性病变的检出率为40%(2/5)。结论CTVE是一种无创的胃肠道检查新技术,对于胃肠道肿瘤的诊断与电子内镜同样有高度敏感性,并能完整显示胃肠道及肠外病灶,但对于小息肉的敏感性不高,对炎症性及扁平病灶的检出率相对较低。     

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.     

Impact of gastrointestinal endoscopy on HIV‐infected children

Objective: To evaluate the role of gastrointestinal (GI) endoscopy in human immunodeficiency virus (HIV)‐infected children with GI problems. Methods: From 1998 to 2002, we retrospectively reviewed all cases of HIV‐infected children presenting with GI problems in which an upper or lower GI endoscopy was indicated. The initial diagnostic endoscopic examination and any repeat endoscopic session leading to a new diagnosis were used in the data analysis. Tissue biopsies were obtained from all abnormal lesions and representative sites of normal‐appearancing GI mucosa. Results: Fourteen patients (median age: 22.5 months) underwent 23 sessions of GI endoscopy, including 10 esophagogastroduodenoscopy, nine colonoscopy and four flexible sigmoidoscopy. Chronic diarrhea was the most common indication, followed by lower GI bleeding, abdominal/retrosternal pain, dysphagia/odynophagia, and upper GI bleeding. Gross endoscopic abnormalities were observed in 78.3%; whereas histological inflammation and opportunistic pathogens were identified in 87% and 43.5%, respectively. Cytomegalovirus was the most common identified pathogen. Abnormal gross findings were significantly associated with histological inflammation and identification of pathogens (P = 0.006 and 0.046, respectively). Specific changes in medical management were made in 50% of cases as a result of endoscopic investigation. Conclusion: If non‐invasive investigations for HIV‐infected children with GI symptoms fail to establish a diagnosis, gastrointestinal endoscopy should be performed and often yields a positive result leading to changes in medical management.