Endoscopic diagnosis and surveillance of Barrett's esophagus

There are many questions regarding the screening and surveiliance of BE for which there are currently no answers. Despite the use of models and extrapolations by some authors to suggest that screening and surveiliance for a cancer of such low incidence will never be justified, others argue just as vociferously that given the continued epidemic rise in incidence of this cancer, the uniformly fatal outcome of these cancers if dianosed after symptoms occur, and the enormous pool of patients remaining at risk for future cancer development, a focused and prudent screening and surveillance strategy for Barrett's-related esophageal adenocarcinoma is justified. The data also show that a single screening examination is probably as effective as almost all subsequent surveilance examinations in detecting advanced neoplasia, and much of the current resource use and energy for screening and surveillance in BE should be directed toward screening. Whether screening should be offered or recommended to only older patients (> 50-55 years), whites, and men is unknown, but it is premature to adopt this strategy until better evidence exist supporting a restricted screening policy. Regarding the optimal surveilance frequency and technique, examinations more frequent than every 3 to 5 years are not justifiable, and until proven otherwise, biopsy specimens should be obtained with the largest forceps that can be used with the endoscopic instrument and "saturation" biopsies from the Barrett's obtained. It is unlikely that too many biopsy specimens can be taken. Furthermore, the safety of this approach has been, proven. It is quite likely that the inverse is not true; clinicians likely can do much more harm by taking too few biopsy specimens. It is hoped that the current intense interest in Barrett's neoplasia allows clinicians to address these critical issues in the years to come and resolve this clinical conundrum.     

Endoscopic therapy for Barrett's esophagus

There are many foreign reports about the endoscopic ablation therapy for Barrett's esophagus. Endoscopic ablation therapy include thermal therapy (electrocoagulation, laser etc.), photodynamic therapy or endoscopic resection and so on. Ablation of Barrett's esophagus by these therapy in combination with adequate acid suppression lead to mucosal replacement by squamous epithelium. But the true value of these endoscopic therapy has not been fully investigated. Further studies are required.     

Endoscopic therapy for Barrett's esophagus

With the increase in the rate of esophageal adenocarcinoma in the United States and the Western world matched with the high morbidity and mortality of esophagectomy, there is an increasing need for new and effective techniques to treat and prevent esophageal adenocarcinoma. A wide variety of endoscopic mucosal ablative techniques have been developed for early esophageal neoplasia. However, long-term control of neoplasic risk has not been demonstrated. Most studies show that specialized intestinal metaplasia may persist underneath neo-squamous mucosa, posing a risk for subsequent neoplastic progression. In this article we review current published literature on endoscopic therapies for the management of Barrett's esophagus.     

Chromoendoscopic diagnosis of Barrett's esophagus

Some kinds of chromoendoscopy have been reported to survey the cases with Barrett's esophagus more effectively, since random biopsy as a gold standard is not an ideal method from the viewpoint of safety, labor or cost effectiveness. Methylene blue (MB) chromoendoscopy has been reported that a targeted biopsy is possible to limit because MB only stains non-dysplastic Barrett's mucosa but not dysplastic one. However, many of supplementary studies have not agreed this recommendation. Crystal violet (CV) chromoendoscopy clearly stains Barrett's mucosa and makes a detailed observation of pit pattern possible. The availability of this method is required a further mass survey although CV chromoendoscopy has been reported to be effective in Barrett's screening. Other chromoendoscopic methods using indigo carmine or fluorescence dye also have been reported to be effective for discovering a dysplastic lesion by some investigator, but the efficacy has not been sufficiently evidenced. Conclusively, chromoendoscopic diagnosis of Barrett's esophagus has not yet got a consensus in the availability for Barrett's surveillance at present in Barrett's Esophagus Chicago Workshop 2003 of AGA.     

Endoscopic evaluation and advanced imaging of Barrett's esophagus

Enhanced visualization techniques are available for Barrett's esophagus and have promise in the detection of dysplasia and cancer. Several of these techniques, such as narrow band imaging and chromoendoscopy, are being applied clinically. These techniques will allow the endoscopist to screen the surface of the Barrett's esophagus to detect areas of neoplasia. Once detected, it is hoped that either magnification techniques, such as confocal laser endomicroscopy, or spectroscopic techniques can be of value in allowing in vivo real-time diagnostic capabilities.     

Histochemical diagnosis of short segment Barrett's esophagus

Recently, we have many chances of findings of Barrett's esophagus in routine endoscopic examination. It is also reported that we have few frequent findings of typical Barrett's esophagus, long segment Barrett's esophagus (LSBE) which is seen predominantly in Europe and United States, however the frequency of finding of short segment Barrett's esophagus (SSBE) and adenocarcinoma derived from SSBE is gradually increasing in Japan. So it is thought that precise diagnosis of SSBE and the evaluation of potential malignancy of SSBE are needed in the present medical management. The present study has shown the differences of characteristics of mucinous contents and malignant potentials between in SSBE and LSBE by use of biopsy specimen taken by endoscopic procedure. It is well known that Barrett's epithelium is categorized gastric fundic type, junctional type and specialized columnar epithelium, especially Barrett's mucosa is characterized by specialized columnar epithelium, e. g. incomplete epithelial type of intestinal metaplasia. We have set up two characteristic groups, gastric mucin dominant and intestinal mucin dominant by using specific mucin staining for MUC2, MUC5AC, Con A and CD10. In results, we confirmed that 80% of specialized columnar epithelia revealed intestinal mucin dominant in LSBE and 77% revealed gastric mucin dominant as compared with 23%, intestinal mucin dominant. Moreover, we have examined the ability of cell proliferation using Ki67-immunostaining in Barrett's epithelia. It was demonstrated that positive immunoactivity of Ki67 in proliferative zone was shown in 37.5% of gastric mucin dominant and 76.5% of intestinal mucin dominant. The results described above suggested that specialized columnar epithelia with intestinal mucin dominant have a higher potential of malignant transformation. We concluded that the evaluation of characteristics of mucinous contents in specialized columnar epithelia plays an important role in determination of high risk group of carcinogenesis in the case of SSBE.     

内镜窄带成像诊断Barrett食管的作用研究

目的 探讨内镜窄带成像在早期发现Barrett仕食管(BE)中的特殊肠上皮化生(SIM)细胞等癌前病变中的作用.方法 2008年6月～12月间,共25例经胃镜检查确诊为内镜BE患者,分别采用普通模式、NBI模式进行观察,并用NBI模式进行BE黏膜腺管开口分型,于改变最明显处取活检行病理检查.结果 在对鳞一柱状上皮交界的病变轮廓、黏膜腺管开口形态及毛细血管结构形态的观察中,NBI显著优于普通内镜;NBI模式下通过Endo分型,其Ⅳ型、V型腺管开口检出SIM的准确性、敏感性、特异性分别为92%、86%及94%.结论 NBI可清晰观察BE黏膜病变轮廓、腺管开口形态及毛细血管结构形态;操作转换简单易行,对BE食管进行靶向活检具有良好指导意义及临床使用价值.     

Barrett's esophagus

The Barrett's esophagus showing columnar metaplasia upward to the esophagus from the esophago-gastric junction is one of the final appearance of reflux esophagitis and important as a precancerous state of esophageal adenocarcinoma. Especially the Barrett's mucosa with intestinal metaplasia has high potential risk for adenocarcinoma. Although the clinical definition of the esophago-gastric junction is not easy, the criteria of the esophago-gastric junction and the Barrett's mucosa proposed by the Japanese Society for Esophageal Diseases is useful. The gastro-esophageal reflux is important in the development of Barrett's mucosa not only in the classical Barrett's esophagus but also in the short-segment Barrett's.     

Barrett's esophagus

Gastroesophageal reflux disease (GERD) is a condition commonly managed in the primary care setting. Patients with GERD may develop reflux esophagitis as the esophagus repeatedly is exposed to acidic gastric contents. Over time, untreated reflux esophagitis may lead to chronic complications such as esophageal stricture or the development of Barrett's esophagus. Barrett's esophagus is a premalignant metaplastic process that typically involves the distal esophagus. Its presence is suspected by endoscopic evaluation of the esophagus, but the diagnosis is confirmed by histologic analysis of endoscopically biopsied tissue. Risk factors for Barrett's esophagus include GERD, white or Hispanic race, male sex, advancing age, smoking, and obesity. Although Barrett's esophagus rarely progresses to adenocarcinoma, optimal management is a matter of debate. Current treatment guidelines include relieving GERD symptoms with medical or surgical measures (similar to the treatment of GERD that is not associated with Barrett's esophagus) and surveillance endoscopy. Guidelines for surveillance endoscopy have been published; however, no studies have verified that any specific treatment or management strategy has decreased the rate of mortality from adenocarcinoma.     

Barrett's esophagus

Esophageal cancer staging is a widely accepted indication for endoscopic ultrasonography (EUS). The evaluation of Barrett's esophagus (BE) with EUS is indicated only when there is high-grade dysplasia or a concern for malignancy in an endoscopic lesion. Because the options for the management of BE and early adenocarcinoma are diverse, proper selection of patients by accurate staging with EUS is critical, particularly when nonoperative management is considered. For example, patients with BE with high-grade dysplasia may be offered esophagectomy in some medical centers, but nonoperative therapies such as endoscopic ablative therapy or mucosal resection may be the preferred treatment options in other gastroenterology practices. This article discusses the scientific evidence for the use of EUS in BE or early esophageal adenocarcinoma.     

Endoscopic and histologic diagnosis of Barrett esophagus

Endoscopy plays an important role in the identification, diagnosis, and treatment of Barrett esophagus. Short-segment (<2-3 cm) and traditional long-segment (>2-3 cm) Barrett esophagus are distinguished solely on the length of metaplastic tissue above the esophagogastric junction. The histologic hallmark of intestinal metaplasia is required to confirm diagnosis. Biopsy specimens obtained from tissue of presumed Barrett esophagus or an irregular Z line confirm metaplastic glandular mucosa and permit evaluation of dysplastic or neoplastic changes. In the appropriate clinical setting, the use of adjunctive diagnostic techniques may facilitate the diagnosis of Barrett esophagus and sequelae such as dysplasia. Chromoendoscopy with high-resolution or magnified endoscopy is simple, safe, and desirable for surveillance but requires additional procedural time. The use of light-induced fluorescence endoscopy and light-scattering spectroscopy (i.e., optical biopsy) is appealing for the diagnosis and characterization of suspicious lesions. Adjunctive endoscopic techniques and adherence to a protocol for performing biopsies facilitate the early detection and subsequent surveillance of Barrett esophagus.     

Barrett's esophagus: observations on diagnosis and management.

Barrett's esophagus is a premalignant condition that may often pass unrecognized in clinical practice. In adults, this condition is generally believed to be caused by chronic gastroesophageal reflux resulting in a metaplastic change in the epithelium of the esophagus. Diagnosis of Barrett's esophagus is established by careful biopsy of the involved esophageal mucosa. Periodic surveillance is recommended because of the risk of carcinoma. Antireflux surgery has not been shown to result consistently in the regression of the metaplastic epithelium, but potent acid suppression offers a new therapeutic approach that leads to healing of esophagitis and the potential regression of Barrett's epithelium.     

Endoscopic diagnosis of chemical burns of the esophagus

Analysis of endoscopic diagnosis of chemical burns of the esophagus permitted the authors to define the direct and indirect signs of esophageal involvement in chemical burns and to assess the severity of involvement. The accuracy of diagnosing the degree of chemical burn from direct signs is rather low during the first three days after caustic injury. Deep necrotic and necrobiotic changes in the esophageal wall can be assessed from indirect signs of chemical injury to the esophagus.     

Carcinogenesis of Barrett's esophagus

Barrett's esophagus is a premalignant condition and remains the number one risk factor for developing adenocarcinoma. Gastro-esophageal reflux disease is a strong risk factor for both esophageal adenocarcinoma and the precancerous lesion Barrett's esophagus. Both of these conditions are related to the reflux of acid and bile into the esophagus. This results in inflammation and cell damage which initiates a sequence of events termed the metaplasia-dysplasia sequence in which the squamous epithelium is replaced by columnar epithelium exhibiting increasing degrees of dysplasia and overt malignancy. The underlying disease mechanisms remain unclear, but tumor suppression genes (p53, p16, APC) and, oncogenes (K-ras, cyclin D1, c-erb-2) seem to cause the malignant transformation of Barrett's esophagus, and the genetic or epigenetic alterations of these genes have been reported.     

窄带成像技术诊断Barrett食管的临床应用价值

目的:通过对Barrett食管(BE)在窄带内镜下的图像特征与组织学的一致性进行比较,探讨窄带成像技术(NBI)诊断BE的临床应用价值.方法:对76例临床拟诊BE的患者进行NBI检查,根据黏膜和血管的形态行NBI图像分类,并与组织病理学进行比较.结果:在NBI模式下,对BE诊断的敏感性、特异性、阳性预测值分别为74.2%、78.6%和93.9%,明显高于常规内镜.与组织学比较,无肠化生的BE,NBI下黏膜形态多表现为A型,高级别黏膜内瘤变(HGD)的黏膜形态全表现为D型,而肠化生(SIM)和低级别黏膜内瘤变(LGD)两者的黏膜形态多表现为C型.结论:NBI可明显提高对BE诊断的准确率,且与组织学有较好的一致性.     

Radiologic diagnosis of Barrett's esophagus: Critical analysis of 65 cases

A recent increase in the number of Barrett's esophagis being diagnosed is probably directly related to a proportional increase in endoscopic biopsies of the esophagus and awareness of premalignant potential of Barrett's mucosa. While the endoscopist can detect Barrett's mucosa with fair degree of accuracy, the radiologic diagnosis of Barrett's esophagus still remains a diagnostic challenge despite several well established radiologic features. We reviewed 65 patients with pathologically proven Barrett's esophagus and found a wide spectrum of radiologic features. These include hiatus hernia in 49, gastroesophageal reflux in 38, strictures in 32, esophagitis in 20, and characteristic Barrett's ulcer in 12. In addition ascending or migrating strictures were found in 10, mucosal pattern simulating areae gastricae in 5, cricopharyngeal dysfunction in 4, and fixed spiral folds in 3 patients. This constellation of radiologic features, some of which have not been previously emphasized, should further assist radiologists in suggesting the diagnosis of Barrett's esophagus.