A randomized, prospective cross-over trial comparing methylene blue-directed biopsy and conventional random biopsy for detecting intestinal metaplasia and dysplasia in Barrett's esophagus

National Institute for Health and Care Excellence (NICE) guidance on monitoring and management of Barrett's oesophagus and stage I oesophageal adenocarcinoma

Barrett's oesophagus is the only known precursor to oesophageal adenocarcinoma, a cancer with very poor prognosis. The main risk factors for Barrett's oesophagus are a history of gastro-oesophageal acid reflux symptoms and obesity. Men, smokers and those with a family history are also at increased risk. Progression from Barrett's oesophagus to cancer occurs via an intermediate stage, known as dysplasia. However, dysplasia and early cancer usually develop without any clinical signs, often in individuals whose symptoms are well controlled by acid suppressant medications; therefore, endoscopic surveillance is recommended to allow for early diagnosis and timely clinical intervention. Individuals with Barrett's oesophagus need to be fully informed about the implications of this diagnosis and the benefits and risks of monitoring strategies. Pharmacological treatments are recommended for control of symptoms, but not for chemoprevention. Dysplasia and stage 1 oesophageal adenocarcinoma have excellent prognoses, since they can be cured with endoscopic or surgical therapies. Endoscopic resection is the most accurate staging technique for early Barrett's-related oesophageal adenocarcinoma. Endoscopic ablation is effective and indicated to eradicate Barrett's oesophagus in patients with dysplasia. Future research should focus on improved accuracy for dysplasia detection via new technologies and providing more robust evidence to support pathways for follow-up and treatment.

Current Status of Image-Enhanced Endoscopy for Early Identification of Esophageal Neoplasms

Advanced esophageal cancer is known to have a poor prognosis. The early detection of esophageal neoplasms, including esophageal dysplasia and early esophageal cancer, is highly important for the accurate treatment of the disease. However, esophageal dysplasia and early esophageal cancer are usually subtle and can be easily missed. In addition to the early detection, proper pretreatment evaluation of the depth of invasion of esophageal cancer is very important for curative treatment. The progression of non-invasive diagnosis via image-enhanced endoscopy techniques has been shown to aid the early detection and estimate the depth of invasion of early esophageal cancer and, as a result, may provide additional opportunities for curative treatment. Here, we review the advancement of image-enhanced endoscopy-related technologies and their role in the early identification of esophageal neoplasms.

Sentinel lymph node biopsy mapped with methylene blue dye alone in patients with breast cancer: A systematic review and meta-analysis

Background

Methylene blue dye is easy to obtain in developing countries and can be used in sentinel lymph node mapping for breast cancer. However, the accuracy of methylene blue alone for sentinel lymph node mapping in breast cancer has not been well defined. In this study, we collected data to assess the feasibility and accuracy of sentinel lymph node biopsy mapped with methylene blue alone in patients with breast cancer.

Methods

We searched the PubMed, EMBASE, and Cochrane Library databases from January 1, 1993, to March 31, 2018. Selected studies had to have a defined group of patients with breast cancer in which MBD alone was used as the mapping technique for SNB.

Results

18 studies were included in this study. The combined identification rate was 91% [95% confidence interval (CI): 88%-94%, I² = 68.3%], and the false negative rate was 13% (95% CI: 9%-18%, I² = 36.7%). The pooled sensitivity, negative predictive value, and accuracy rate were 87% (95% CI: 82%-91%, I² = 37.5%), 91% (95% CI: 87%-93%, I² = 32.4%) and 94% (95% CI: 92%-96%, I² = 29%), respectively.

Conclusions

This meta-analysis found that mapping sentinel lymph node locations with methylene blue dye alone results in an acceptable identification rate but an excessive false negative rate according to the American Society of Breast Surgeons’ recommendations. Caution is warranted when using methylene blue dye alone as the mapping method for sentinel lymph node biopsy.

Development of Image-enhanced Endoscopy of the Gastrointestinal Tract: A Review of History and Current Evidences

Endoscopy imaging of the gastrointestinal (GI) tract has evolved tremendously over the last few decades. Key milestones in the development of endoscopy imaging include the use of various dyes for chromoendoscopy, the application of optical magnification in endoscopy, the introduction of high-definition image capturing and display technology and the application of altered illuminating light to achieve vascular and surface enhancement. Aims of this review paper are to summarize the development and evolution of modern endoscopy imaging and in particular, imaged-enhanced endoscopy (IEE), to promote appropriate usage, and to guide future development of good endoscopy practice. A search of PubMed database was performed to identify articles related to IEE of the GI tract. Where appropriate, landmark trials and high-quality meta-analyses and systematic reviews were used in the discussion. In this review, the developments and evolutions in endoscopy imaging and in particular, IEE, were summarized into discernible eras and the literature evidence with regard to the strengths and weaknesses in term of their detection and characterization capability in each of these eras were discussed. It is in the authors' opinion that IEE is capable of fairly good detection and accurate characterization of various GI lesions but such benefits may not be readily reaped by those who are new in the field of luminal endoscopy. Exposure and training in making confident diagnoses using these endoscopy imaging technologies are required in tandem with these new developments in order to fully embrace and adopt the benefits.

Optimizing the diagnosis and therapy of Barrett's esophagus

The incidence of Barrett's esophagus (BE) in the Western world has increased over the last decades. BE is considered a premalignant lesion that can progress to esophageal adenocarcinoma (EAC), a highly aggressive malignancy with poor survival rates. The close association between BE and EAC highlights the need for an early diagnosis in order to improve survival and outcomes in this group of patients. Although the evidence for BE screening with conventional endoscopy is controversial and limited by cost-effectiveness studies, screening can be suggested in patients with chronic gastroesophageal reflux disease (GERD) and two or more risk factors for EAC. Less invasive techniques with lower costs and higher acceptability by the patients may be useful for screening in the general population. Several novel techniques have been described to aid in the early diagnosis and management of BE and dysplasia. However, these techniques have shown variable results with higher costs, the need of specific training, and variable inter-observer imaging interpretation, making its widespread implementation problematic. High-definition/high-resolution white-light endoscopy (WLE) continues to be a well-accepted technique for the evaluation and surveillance of patients with BE. Further studies are required in order to establish the efficacy of less invasive methods that can be performed in an outpatient setting for BE screening in higher risk individuals.

Endoscopic submucosal dissection and endoscopic mucosal resection for early stage esophageal cancer

Mortality from esophageal cancer remains high despite advances in medical therapy. Although the incidence of squamous cell carcinoma of the esophagus remains unchanged, the incidence of the esophageal adenocarcinoma has increased over time. Gastroesophageal reflux disease (GERD and obesity are contributing factors to the development of Barrett's esophagus and subsequent development of adenocarcinoma. Early recognition of the disease can lead to resection of esophageal cancer prior to the development of lymphovascular invasion. Various modalities have been implemented to aid identification of precancerous lesions and early esophageal cancer. Chromoendoscopy, narrowband imaging and endoscopic ultrasound examination are typically used for evaluating early esophageal lesions. Recently, confocal laser endomicroscopy (CLE) and volumetric laser scanning were implemented with promising results. Endoscopic management of early esophageal cancer may be done using endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). Both techniques allow resection of the mucosa (and possibly a portion of the submucosa) containing the early tumor without interruption of deeper layers. A submucosal injection creating a cushion coupled with snare resection or cap assisted mucosal suction followed by ligation and snare resection are the most common techniques of EMR. EMR can remove lesions less than 2 cm in size en bloc. Larger lesions may require resection in piecemeal fashion. This may limit assessment of the margins of the lesion and orienting the lesion's border. ESD offers en bloc dissection of the lesion regardless of its size. ESD is performed with specialized needle knives, which allow incision followed by careful dissection of the lesion within the submucosal layer. Tumor recurrence after ESD is rare but the technique is labor intensive and has an increased risk of perforation. Esophageal stenosis remains a concern after extensive EMR or ESD. Dilation with balloon or stent placement is usually sufficient to treat post-resection stenosis.

Role of endoscopy in early oesophageal cancer

Incidence of oesophageal adenocarcinoma has increased exponentially in the West over the past few decades. Following detection of advanced cancers, 5-year survival rates remain bleak, making identification of early neoplasia, which has a better outcome, important. Detection of subtle oesophageal lesions during endoscopy can be challenging, and advanced imaging techniques might improve their detection. High-definition endoscopy has become a standard in most endoscopy centres, and this technology probably provides better delineation of mucosal features than standard-definition endoscopy. Various image enhancement techniques are now available with the development of new electronics and software systems. Image enhancement with chromoendoscopy using dyes has been a cost-effective option for many years, yet these techniques have been replaced in some contexts by electronic chromoendoscopy, which can be used with the press of a button. However, Lugol's chromoendoscopy remains the gold standard to identify squamous dysplasia. Identification and characterization of subtle neoplastic lesions could help to target biopsies and perform endoscopic resection for better local staging and definitive therapy. In vivo histology with techniques such as confocal endomicroscopy could make endotherapy feasible within a shorter timescale than when relying on histology on tissue samples. Once early neoplasia is identified, treatments include endoscopic resection, endoscopic submucosal dissection or various ablative techniques. Endotherapy has the advantage of being a less invasive technique than oesophagectomy, and is associated with lower mortality and morbidity. Endoscopic ablation therapies have evolved over the past few years, with radiofrequency ablation showing the best results in terms of success rates and complications in Barrett dysplasia.

Advances in the Endoscopic Diagnosis of Barrett Esophagus

BACKGROUND

Barrett esophagus (BE) continues to be a major risk factor for developing esophageal adenocarcinoma.

METHODS

We review the risk factors, diagnosis, and management of BE, with an emphasis on the most current endoscopic diagnostic modalities for BE.

RESULTS

Novel diagnostic modalities have emerged to address the inadequacies of standard, untargeted biopsies, such as dye-based and virtual chromoendoscopy, endoscopic mucosal resection, molecular biomarkers, optical coherence tomography, confocal laser endomicroscopy, volumetric laser endomicroscopy, and endocytoscopy. Treatment of BE depends on the presence of intramucosal cancer or dysplasia, particularly high-grade dysplasia with or without visible mucosal lesions.

CONCLUSIONS

Recent advances in endoscopic diagnostic tools demonstrate promising results and help to mitigate the shortcomings of the Seattle protocol. Future research as well as refining these tools may help aid them in replacing standard untargeted biopsies.

ASGE Technology Committee systematic review and meta-analysis assessing the ASGE Preservation and Incorporation of Valuable Endoscopic Innovations thresholds for adopting real-time imaging-assisted endoscopic targeted biopsy during endoscopic surveillance of Barrett's esophagus

BACKGROUND AND AIMS

Endoscopic real-time imaging of Barrett's esophagus (BE) with advanced imaging technologies enables targeted biopsies and may eliminate the need for random biopsies to detect dysplasia during endoscopic surveillance of BE. This systematic review and meta-analysis was performed by the American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee to specifically assess whether acceptable performance thresholds outlined by the ASGE Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) document for clinical adoption of these technologies have been met.

METHODS

We conducted meta-analyses calculating the pooled sensitivity, negative predictive value (NPV), and specificity for chromoendoscopy by using acetic acid and methylene blue, electronic chromoendoscopy by using narrow-band imaging, and confocal laser endomicroscopy (CLE) for the detection of dysplasia. Random effects meta-analysis models were used. Statistical heterogeneity was evaluated by means of I(2) statistics.

RESULTS

The pooled sensitivity, NPV, and specificity for acetic acid chromoendoscopy were 96.6% (95% confidence interval [CI], 95-98), 98.3% (95% CI, 94.8-99.4), and 84.6% (95% CI, 68.5-93.2), respectively. The pooled sensitivity, NPV, and specificity for electronic chromoendoscopy by using narrow-band imaging were 94.2% (95% CI, 82.6-98.2), 97.5% (95% CI, 95.1-98.7), and 94.4% (95% CI, 80.5-98.6), respectively. The pooled sensitivity, NPV, and specificity for endoscope-based CLE were 90.4% (95% CI, 71.9-97.2), 98.3% (95% CI, 94.2-99.5), and 92.7% (95% CI, 87-96), respectively.

CONCLUSIONS

Our meta-analysis indicates that targeted biopsies with acetic acid chromoendoscopy, electronic chromoendoscopy by using narrow-band imaging, and endoscope-based CLE meet the thresholds set by the ASGE PIVI, at least when performed by endoscopists with expertise in advanced imaging techniques. The ASGE Technology Committee therefore endorses using these advanced imaging modalities to guide targeted biopsies for the detection of dysplasia during surveillance of patients with previously nondysplastic BE, thereby replacing the currently used random biopsy protocols.

Advances in the endoscopic diagnosis and treatment of Barrett's neoplasia

Barrett's oesophagus is a well-recognised precursor of oesophageal adenocarcinoma. The incidence of oesophageal adenocarcinoma is continuing to rise in the Western world with dismal survival rates. In recent years, efforts have been made to diagnose Barrett's earlier and improve surveillance techniques in order to pick up cancerous changes earlier. Recent advances in endoscopic therapy for early Barrett's cancers have shifted the paradigm away from oesophagectomy and have yielded excellent results.

Emerging optical methods for surveillance of Barrett's oesophagus

The rapid rise in incidence of oesophageal adenocarcinoma has motivated the need for improved methods for surveillance of Barrett's oesophagus. Early neoplasia is flat in morphology and patchy in distribution and is difficult to detect with conventional white light endoscopy (WLE). Light offers numerous advantages for rapidly visualising the oesophagus, and advanced optical methods are being developed for wide-field and cross-sectional imaging to guide tissue biopsy and stage early neoplasia, respectively. We review key features of these promising methods and address their potential to improve detection of Barrett's neoplasia. The clinical performance of key advanced imaging technologies is reviewed, including (1) wide-field methods, such as high-definition WLE, chromoendoscopy, narrow-band imaging, autofluorescence and trimodal imaging and (2) cross-sectional techniques, such as optical coherence tomography, optical frequency domain imaging and confocal laser endomicroscopy. Some of these instruments are being adapted for molecular imaging to detect specific biological targets that are overexpressed in Barrett's neoplasia. Gene expression profiles are being used to identify early targets that appear before morphological changes can be visualised with white light. These targets are detected in vivo using exogenous probes, such as lectins, peptides, antibodies, affibodies and activatable enzymes that are labelled with fluorescence dyes to produce high contrast images. This emerging approach has potential to provide a 'red flag' to identify regions of premalignant mucosa, outline disease margins and guide therapy based on the underlying molecular mechanisms of cancer progression.

Multiple-Band Imaging Provides Better Value Than White-light Endoscopy in Detection of Dysplasia in Patients With Barrett's Esophagus

BACKGROUND & AIMS

Surveillance of patients with Barrett's esophagus usually is performed with standard white-light endoscopy (SDWLE) and the collection of 4 biopsy specimens (every 1-2 cm of the metaplastic segment), based on Seattle protocol. New endoscopic techniques are used routinely, but have been validated based only on low-grade evidence. We aimed to validate the use of high-definition magnifying endoscopy with multiple-band imaging (HDMEMBI) with a targeted biopsy collection for the detection of dysplasia, using SDWLE with quadrant biopsy collection as the reference.

METHODS

In a cross-over study, patients with suspected or histologically verified BE (without known neoplasia) seen at a tertiary referral high-volume endoscopy center in Sweden, from November 2009 through November 2012, were assigned randomly to undergo HDMEMBI (n = 63) or SDWLE (n = 47) as the initial procedure, followed by the other procedure in 1 to 4 months. The primary end point was the total number of subjects found to have low-grade dysplasia or high-grade dysplasia (HGD) by each technique. Secondary end points included the number of biopsy specimens taken and the duration of each procedure.

RESULTS

There was no significant difference between groups in diagnostic yield for low-grade dysplasia (14 in HDMEMBI vs. 13 in SDWLE) or HGD. Four HGDs were found: 3 using HDMEMBI and 1 using SDWLE. Significantly fewer biopsy specimens were collected during the HDMEMBI procedure (P < .001). The diagnostic yield for the detection of dysplasia per biopsy specimen collected therefore was significantly higher for HDMEMBI than SDWLE (0.25 vs. 0.07; P = .018). There was no significant difference in the duration of procedures.

CONCLUSIONS

There is no significant difference in the detection of dysplastic lesions using HDMEMBI with targeted collection of biopsy specimens vs SDWLE with 4-quadrant biopsy specimen collection. However, HDMEMBI requires the collection of significantly fewer biopsy specimens, providing better value for health care providers. ClinicalTrials.gov number: NCT01694511.

Endoscopic imaging in Barrett's esophagus

Barrett's esophagus is the only known precursor that predisposes patients to the development of esophageal adenocarcinoma. The current recommended surveillance method is targeted biopsies of any abnormalities followed by random four-quadrant biopsies every 2 cm using standard white light endoscopy. Compliance with this and sampling error are two of the biggest problems. Several novel imaging technologies have been developed to aid the diagnosis of early neoplasia in Barrett's esophagus. There are emerging data that some of these new modalities can increase the yield of detecting dysplasia. This review will discuss some of the present available techniques and technologies including chromoendoscopy, narrow-band imaging, autofluorescence imaging, optical coherence tomography, confocal endomicroscopy and endocytoscopy. Based on the current evidence, these imaging modalities appear to be promising as adjunctive tools to white light endoscopy. A few of them, nevertheless, remain experimental due to expense, lack of expertise, generalizability as well as reproducibility of results.

Endoscopic assessment and management of early esophageal adenocarcinoma

Esophageal carcinoma affects more than 450000 people worldwide and the incidence is rapidly increasing. In the United States and Europe, esophageal adenocarcinoma has superseded esophageal squamous cell carcinoma in its incidence. Esophageal cancer has a high mortality rates secondary to the late presentation of most patients at advanced stages. Endoscopic screening is recommended for patients with multiple risk factors for cancer in Barrett’s esophagus. These risk factors include chronic gastroesophageal reflux disease, hiatal hernia, advanced age, male sex, white race, cigarette smoking, and obesity. The annual risk of esophageal cancer is approximately 0.25% for patients without dysplasia and 6% for patients with high-grade dysplasia. Twenty percent of all esophageal adenocarcinoma in the United States is early stage with disease confined to the mucosa or submucosa. The significant morbidity and mortality of esophagectomy make endoscopic treatment an attractive option. The American Gastroenterological Association recommends endoscopic eradication therapy for patients with high-grade dysplasia. Endoscopic modalities for treatment of early esophageal adenocarcinoma include endoscopic resection techniques and endoscopic ablative techniques such as radiofrequency ablation, photodynamic therapy and cryoablation. Endoscopic therapy should be precluded to patients with no evidence of lymphovascular invasion. Local tumor recurrence is low after endoscopic therapy and is predicted by poor differentiation of tumor, positive lymph node and submucosal invasion. Surgical resection should be offered to patients with deep submucosal invasion.

Operable gastro-oesophageal junctional adenocarcinoma: Where to next?

Oesophageal junctional adenocarcinoma is a challenging and increasingly common disease. Optimisation of pre-operative staging and consolidation of surgery in large volume centres have improved outcomes, however the preferred adjunctive treatment approach remains a matter of debate. This review examines the benefits of neoadjuvant, peri-operative, and post-operative chemotherapy and chemoradiotherapy in this setting in an attempt to reach an evidence based conclusion. Recent findings relating to the molecular characterisation of oesophagogastric cancer and their impact on therapeutics are explored, in addition to the potential benefits of fluoro-deoxyglucose positron emission tomography (FDG-PET) directed therapy. Finally, efforts to decrease the incidence of junctional adenocarcinoma using early intervention in Barrett’s oesophagus are discussed, including the roles of screening, endoscopic mucosal resection, ablative therapies and chemoprevention.

State of the art in advanced endoscopic imaging for the detection and evaluation of dysplasia and early cancer of the gastrointestinal tract

Ideally, endoscopists should be able to detect, characterize, and confirm the nature of a lesion at the bedside, minimizing uncertainties and targeting biopsies and resections only where necessary. However, under conventional white-light inspection – at present, the sole established technique available to most of humanity – premalignant conditions and early cancers can frequently escape detection. In recent years, a range of innovative techniques have entered the endoscopic arena due to their ability to enhance the contrast of diseased tissue regions beyond what is inherently possible with standard white-light endoscopy equipment. The aim of this review is to provide an overview of the state-of-the-art advanced endoscopic imaging techniques available for clinical use that are impacting the way precancerous and neoplastic lesions of the gastrointestinal tract are currently detected and characterized at endoscopy. The basic instrumentation and the physics behind each method, followed by the most influential clinical experience, are described. High-definition endoscopy, with or without optical magnification, has contributed to higher detection rates compared with white-light endoscopy alone and has now replaced ordinary equipment in daily practice. Contrast-enhancement techniques, whether dye-based or computed, have been combined with white-light endoscopy to further improve its accuracy, but histology is still required to clarify the diagnosis. Optical microscopy techniques such as confocal laser endomicroscopy and endocytoscopy enable in vivo histology during endoscopy; however, although of invaluable assistance for tissue characterization, they have not yet made transition between research and clinical use. It is still unknown which approach or combination of techniques offers the best potential. The optimal method will entail the ability to survey wide areas of tissue in concert with the ability to obtain the degree of detailed information provided by microscopic techniques. In this respect, the challenging combination of autofluorescence imaging and confocal endomicroscopy seems promising, and further research is awaited.

Management controversies in Barrett's oesophagus

The management of Barrett's oesophagus and associated neoplasia has evolved considerably in recent years. Modern endoscopic strategies including endoscopic resection and mucosal ablation can eradicate dysplastic Barrett's and prevent progression to invasive oesophageal cancer. However, several aspects of Barrett's management remain controversial including the stage in the disease process at which to intervene, and the choice of endoscopic or surgical therapy. A review of articles pertaining to the management of Barrett's oesophagus with or without associated neoplasia, was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline, Embase and Cochrane databases were searched to identify literature relevant to eight pre-defined areas of clinical controversy. The following search terms were used: Barrett's oesophagus; dysplasia; intramucosal carcinoma; endotherapy; endoscopic resection; ablation; oesophagectomy. A significant body of evidence exists to support early endoscopic therapy for high-grade dysplasia (HGD). Although not supported by randomised controlled trial evidence, endoscopic therapy is now favoured ahead of oesophagectomy for most patients with HGD. Focal intramucosal (T1a) carcinomas can be managed effectively using endoscopic and surgical therapy, however surgery should be considered the first line therapy where there is submucosal invasion (T1b). Treatment of low grade dysplasia is not supported at present due to widespread over-reporting of the disease. The role of surveillance endoscopy in non-dysplastic Barrett's remains controversial.

British Society of Gastroenterology guidelines on the diagnosis and management of Barrett's oesophagus

These guidelines provide a practical and evidence-based resource for the management of patients with Barrett's oesophagus and related early neoplasia. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument was followed to provide a methodological strategy for the guideline development. A systematic review of the literature was performed for English language articles published up until December 2012 in order to address controversial issues in Barrett's oesophagus including definition, screening and diagnosis, surveillance, pathological grading for dysplasia, management of dysplasia, and early cancer including training requirements. The rigour and quality of the studies was evaluated using the SIGN checklist system. Recommendations on each topic were scored by each author using a five-tier system (A+, strong agreement, to D+, strongly disagree). Statements that failed to reach substantial agreement among authors, defined as >80% agreement (A or A+), were revisited and modified until substantial agreement (>80%) was reached. In formulating these guidelines, we took into consideration benefits and risks for the population and national health system, as well as patient perspectives. For the first time, we have suggested stratification of patients according to their estimated cancer risk based on clinical and histopathological criteria. In order to improve communication between clinicians, we recommend the use of minimum datasets for reporting endoscopic and pathological findings. We advocate endoscopic therapy for high-grade dysplasia and early cancer, which should be performed in high-volume centres. We hope that these guidelines will standardise and improve management for patients with Barrett's oesophagus and related neoplasia.

Advanced imaging technologies increase detection of dysplasia and neoplasia in patients with Barrett's esophagus: a meta-analysis and systematic review

BACKGROUND & AIMS

US guidelines recommend surveillance of patients with Barrett's esophagus (BE) to detect dysplasia. BE conventionally is monitored via white-light endoscopy (WLE) and a collection of random biopsy specimens. However, this approach does not definitively or consistently detect areas of dysplasia. Advanced imaging technologies can increase the detection of dysplasia and cancer. We investigated whether these imaging technologies can increase the diagnostic yield for the detection of neoplasia in patients with BE, compared with WLE and analysis of random biopsy specimens.

METHODS

We performed a systematic review, using Medline and Embase, to identify relevant peer-review studies. Fourteen studies were included in the final analysis, with a total of 843 patients. Our metameter (estimate) of interest was the paired-risk difference (RD), defined as the difference in yield of the detection of dysplasia or cancer using advanced imaging vs WLE. The estimated paired-RD and 95% confidence interval (CI) were obtained using random-effects models. Heterogeneity was assessed by means of the Q statistic and the I(2) statistic. An exploratory meta-regression was performed to look for associations between the metameter and potential confounders or modifiers.

RESULTS

Overall, advanced imaging techniques increased the diagnostic yield for detection of dysplasia or cancer by 34% (95% CI, 20%-56%; P < .0001). A subgroup analysis showed that virtual chromoendoscopy significantly increased the diagnostic yield (RD, 0.34; 95% CI, 0.14-0.56; P < .0001). The RD for chromoendoscopy was 0.35 (95% CI, 0.13-0.56; P = .0001). There was no significant difference between virtual chromoendoscopy and chromoendoscopy, based on Student t test analysis (P = .45).

CONCLUSIONS

Based on a meta-analysis, advanced imaging techniques such as chromoendoscopy or virtual chromoendoscopy significantly increase the diagnostic yield for identification of dysplasia or cancer in patients with BE.

Red flag imaging techniques in Barrett's esophagus

The key to detection and treatment of early neoplasia in Barrett's esophagus (BE) is thorough and careful inspection of the Barrett's segment. The greatest role for red flag techniques is to help identify neoplastic lesions for targeted biopsy and therapy. High-definition white light endoscopy (HD-WLE) can potentially improve endoscopic imaging of BE compared with standard endoscopy, but little scientific evidence supports this. The addition of autofluorescence imaging to HD-WLE and narrow band imaging increases sensitivity and the false-positive rate without significantly improving overall detection of BE-related neoplasia.

Screening for precancerous lesions of upper gastrointestinal tract: from the endoscopists' viewpoint

Upper gastrointestinal tract cancers are one of the most important leading causes of cancer death worldwide. Diagnosis at late stages always brings about poor outcome of these malignancies. The early detection of precancerous or early cancerous lesions of gastrointestinal tract is therefore of utmost importance to improve the overall outcome and maintain a good quality of life of patients. The desire of endoscopists to visualize the invisibles under conventional white-light endoscopy has accelerated the advancements in endoscopy technologies. Nowadays, image-enhanced endoscopy which utilizes optical- or dye-based contrasting techniques has been widely applied in endoscopic screening program of gastrointestinal tract malignancies. These contrasting endoscopic technologies not only improve the visualization of early foci missed by conventional endoscopy, but also gain the insight of histopathology and tumor invasiveness, that is so-called optical biopsy. Here, we will review the application of advanced endoscopy technique in screening program of upper gastrointestinal tract cancers.

[Screening for adenocarcinoma in Barrett's esophagus: yes or no, when and how?]

Barrett's esophagus (BE) is the main recognized risk factor for the development of esophageal adenocarcinoma (EAC). The incidence of this cancer and its associated mortality has increased in developed countries during the last few years. Detection of EAC at earlier stages could potentially improve survival dramatically in these patients, which is especially important as mortality from EAC remains high despite the available treatments. Therefore, endoscopic surveillance is an attractive option for patients with Barrett's esophagus. Consequently, periodic endoscopic surveillance is recommended by all the International Gastroenterology Societies in an attempt to detect EAC at an early and potentially curable stage. Currently, the frequency of endoscopic surveillance and its need in Barrett's esophagus with low-grade dysplasia or without dysplasia are under discussion. This review presents the available evidence in order to assist clinicians in the decision-making process.

Longer inspection time is associated with increased detection of high-grade dysplasia and esophageal adenocarcinoma in Barrett's esophagus

BACKGROUND

Current guidelines recommend that endoscopic surveillance of Barrett's esophagus (BE) be performed by using a strict biopsy protocol. However, novel methods to improve BE surveillance are still needed.

OBJECTIVE

To evaluate the impact of Barrett's inspection time (BIT) on yield of surveillance.

DESIGN

Post hoc analysis of data obtained from a clinical trial.

SETTING

Five tertiary referral centers.

PATIENTS

Patients undergoing BE surveillance.

INTERVENTIONS

Coordinators prospectively recorded the time spent inspecting the BE mucosa with a stopwatch.

MAIN OUTCOME MEASUREMENTS

Endoscopically suspicious lesions, high-grade dysplasia (HGD)/esophageal adenocarcinoma (EAC).

RESULTS

A total of 112 patients underwent endoscopic surveillance by 11 individual endoscopists. Patients with longer BITs were more likely to have an endoscopically suspicious lesion (P < .001) and more endoscopically suspicious lesions (P = .0001) and receive a diagnosis of HGD/EAC (P = .001). There was a direct correlation between the endoscopist's mean BIT per centimeter of BE and the detection of patients with HGD/EAC (ρ = .63, P = .03). Endoscopists who had an average BIT longer than 1 minute per centimeter of BE detected more patients with endoscopically suspicious lesions (54.2% vs 13.3%, P = .04), and there was a trend toward a higher detection rate of HGD/EAC (40.2% vs 6.7%, P = .06).

LIMITATIONS

Post hoc analysis of an enriched study population and experienced endoscopists at tertiary referral centers.

CONCLUSIONS

Longer time spent inspecting the BE segment is associated with the increased detection of HGD/EAC. Taking additional time to perform a thorough examination of the BE mucosa may serve as an easy and widely available method to improve the yield of BE surveillance.

Advanced endoscopic imaging in Barrett's oesophagus

Barrett's oesophagus is a metaplastic condition with an inherent risk of progression to adenocarcinoma. It is essential to identify dysplastic changes within Barrett's oesophagus in order to individualise surveillance strategies and establish which patients warrant endoscopic treatment. There is a trend towards endoscopic resection of focal high-grade dysplasia followed by whole segment ablation. However, endoscopic identification of dysplastic lesions is unreliable and subjective making targeted therapy extremely difficult. In addition, the current practice of taking random quadrantic biopsies may miss dysplastic disease and intramucosal adenocarcinoma. Several advanced endoscopic imaging techniques have been described and tested in clinical trials in an effort to improve the detection of early lesions, although none are routinely used in clinical practice. In this article we will review these techniques and discuss their potential for clinical implementation. We will also discuss the potential benefits of multimodal imaging and highlight several newer techniques which have shown early promise for in vivo diagnosis.

Confocal endomicroscopy (CEM) improves efficiency of Barrett surveillance

BACKGROUND

Endoscopists with extensive experience with confocal endomicroscopy (CEM) have demonstrated that this technology is useful for Barrett's esophagus (BE) surveillance. However, data on endoscopists with minimal experience with this technique are limited.

HYPOTHESIS

For BE surveillance, an endoscopist with minimal experience in CEM-guided biopsy would achieve a similar diagnostic yield with fewer biopsies when compared to the random 4-quadrant biopsy protocol.

OBJECTIVE

To compare the diagnostic yields of CEM-guided biopsy technique with the random 4-quadrant biopsy protocol.

DESIGN

Randomized controlled trial.

SETTING

Tertiary care center.

PATIENTS

Patients with BE.

METHODS

Out of 18 patients who underwent routine BE surveillance, 11 and 7 were randomly assigned to group A (CEM-guided) and to group B (random 4-quadrant biopsy), respectively. The pathologists were blinded to all clinical information.

RESULTS

Mean length of endoscopic Barrett was similar in both groups, (5.1 vs. 6.3 cm, p=0.51). The diagnostic yields for detecting SIM (63.6% vs. 59.5%, p=0.5), low grade dysplasia (11. 6% vs. 11.2%, p=NS), high grade dysplasia (10.1% vs. 11.5%, p=0.88). Although the total number of individual mucosal biopsy performed were 52% lower in the CEM group (129 vs. 269), the overall diagnostic yield (85.3% vs. 82.2%, p=0.53) was similar in both groups.

LIMITATIONS

Small sample size.

CONCLUSIONS

For BE surveillance, limited data suggested that endoscopists with minimal experience in CEM can effective use this technology for "smart" biopsy to decrease the need for intense tissue sampling but without lowering the diagnostic yield in detecting dysplasia.

Advanced endoscopic imaging in Barrett's oesophagus: A review on current practice

Over the last few years, improvements in endoscopic imaging technology have enabled identification of dysplasia and early cancer in Barrett’s oesophagus. New techniques should exhibit high sensitivities and specificities and have good interobserver agreement. They should also be affordable and easily applicable to the community gastroenterologist. Ideally, these modalities must exhibit the capability of imaging wide areas in real time whilst enabling the endoscopist to specifically target abnormal areas. This review will specifically focus on some of the novel endoscopic imaging modalities currently available in routine practice which includes chromoendoscopy, autofluorescence imaging and narrow band imaging.

Role of narrow band imaging in Barrett's esophagus

The present recommended strategy for detection of dysplasia and cancer in Barrett's esophagus is by randomly carrying out four quadrant biopsies every 2 cm. This approach is however prone to sampling error. Narrow band imaging has been routinely available for clinical use for more than half a decade now. This review will focus on the available data to date on the role of narrow band imaging in the detection and characterization of specialized intestinal metaplasia, high grade dysplasia and intramucosal cancer in Barrett's esophagus.

State of the art in the endoscopic imaging and ablation of Barrett's esophagus

Barrett's esophagus is the result of long-term acid reflux and is a precursor to esophageal adenocarcinoma. Surgical resection of the esophagus has been the mainstay of treatment for high grade dysplasia and early cancer. However, recent advances in the endoscopic imaging and ablation technologies have made esophagectomy avoidable in patients with dysplasia and superficial neoplasia. In this article, we review the most relevant endoscopic imaging technologies, such as chromoendoscopy, narrow band and autofluorescence imaging, and confocal laser endomicroscopy. We also review the various endoscopic ablation technologies, such as endoscopic mucosal resection, photodynamic therapy, radiofrequency ablation, and cryotherapy. Finally, we focus on the studies that evaluate the efficacy of these imaging and ablation technologies in finding and eradicating neoplastic Barrett's esophagus.

[Endoscopic technique in endobrachyoesophagus diagnosis: Chromoendoscopy and acetic acid]

Screening for complications of neoplastic Barrett's oesophagus requires a tedious blind standardized protocol biopsies quadrant every 1 to 2cm depending on the morphology of the Barrett's epithelium (Protocol of Seattle). To achieve that biopsies targeted to areas suspicious of dysplasia, a method of high sensitivity is required. Chromoendoscopy has been developed in this direction. Acetic acid combined with high resolution endoscopy and zooming represents an aid in the preparation of the oesophageal mucosa for visualization of suspicious anomalies. It is safe, cheap and easy to use. Acetic acid has proven its value in improving the visibility of the pit pattern. Several vital dyes have been tested, including methylene blue, indigo carmine and crystal violet, with mixed results. The FICE(®) and NBI(®), immediate, reversible and attractive virtual chromoendoscopy techniques represent interesting tools for improving sensitivity in screening for Barrett's oesophagus and its complications. Confocal endomicroscopy, which is similar as a "per-endoscopic real time histological examination", seems to be equally a promising technique in detection of Barrett's oesophagus associated neoplasia. But these tools which are capable of improvement so far, have not proved their use on a large population. For this, the systematic biopsy protocol Seattle remains the "gold standard" in monitoring the Barrett's oesophagus.

Endoscopic techniques for recognizing neoplasia in Barrett's esophagus: which should the clinician use?

PURPOSE OF REVIEW

The key to prevention and cure of esophageal adenocarcinoma is the detection and eradication of neoplasia in patients with Barrett's esophagus. Multiple tools and technologies are emerging for this purpose.

RECENT FINDINGS

A detailed white light examination with high-resolution endoscopy and recognition of lesions is paramount. A variety of imaging modalities are being studied for the detection of neoplasia in Barrett's esophagus. Chromoendoscopy, narrow band imaging, and autofluorescence provide a way to target suspicious areas. Confocal endomicroscopy and optical coherence tomography are means to pinpoint imaging to obtain information about the tissue microarchitecture.

SUMMARY

The key to detection of neoplasia is a careful white light examination with high-resolution endoscopy and recognition of lesion characteristics. Additional imaging modalities may enhance targeting of lesions or provide more information at a focused level. Many of these modalities have yet to be validated in prospective randomized, multicenter trials.

Optimal endoluminal treatment of Barrett's esophagus: integrating novel strategies into clinical practice

Endoluminal therapy has become the first-choice treatment over the last 5 years for early Barrett's neoplasia limited to the mucosa. Long-term follow-up data on endoscopic resection have demonstrated the oncological safety of endoscopic resection in comparison to surgery. However, there is a high rate of recurrent disease, which can be avoided using additional ablation of the remaining Barrett. Radiofrequency ablation was recently introduced as an efficacious means to ablate Barrett's epithelium with a better safety profile than older ablation techniques. Recent studies show that endoscopic resection can be safely combined with radiofrequency ablation for treating dysplastic Barrett's after removal of visible lesions. This constitutes a completely new treatment paradigm that will be integrated in routine clinical practice in the forthcoming years.

Treatment for Barrett's oesophagus

BACKGROUND

Treatments for Barrett's oesophagus, the precursor lesion of adenocarcinoma, are available but whether these therapies effectively prevent the development of adenocarcinoma, and in some cases eradicate the Barrett's oesophagus segment, remains unclear.

OBJECTIVES

To summarise, quantify and compare the efficacy of pharmacological, surgical and endoscopic treatments for the eradication of dysplastic and non-dysplastic Barrett's oesophagus and prevention of these states from progression to adenocarcinoma.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2004, issue 4), MEDLINE (1966 to June 2008) and EMBASE (1980 to June 2008).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing medical, endoscopic or non-resectional surgical treatments for Barrett's oesophagus. The primary outcome measures were complete eradication of Barrett's and dysplasia at 12 months, and reduction in the number of patients progressing to cancer at five years or latest time point.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data and assessed the quality of the trials included in the analysis.

MAIN RESULTS

Sixteen studies, including 1074 patients, were included. The mean number of participants in the studies was small (n = 49; range 8 to 208). Most studies did not report on the primary outcomes. Medical and surgical interventions to reduce symptoms and sequelae of gastro-oesophageal reflux disease (GORD) did not induce significant eradication of Barrett's oesophagus or dysplasia. Endoscopic therapies (photodynamic therapy (PDT with aminolevulinic acid or porfimer sodium), argon plasma coagulation (APC) and radiofrequency ablation (RFA)) all induced regression of Barrett's oesophagus and dysplasia. The data for photodynamic therapy were heterogeneous with a mean eradication rate of 51% for Barrett's oesophagus and between 56% and 100% for dysplasia, depending on the treatment regimens. The variation in photodynamic therapy eradication rates for dysplasia was dependent on the drug, source and dose of light. Radiofrequency ablation resulted in eradication rates of 82% and 94% for Barrett's oesophagus and dysplasia respectively, compared to a sham treatment. Endoscopic treatments were generally well tolerated, however all were associated with some buried glands, particularly following argon plasma coagulation and photodynamic therapy, as well as photosensitivity and strictures induced by porfimer sodium based photodynamic therapy in particular.

AUTHORS' CONCLUSIONS

Despite their failure to eradicate Barrett's oesophagus, the role of medical and surgical interventions to reduce the troubling symptoms and sequelae of GORD is not questioned. Whether therapies for GORD reduce the cancer risk is not yet known. Ablative therapies have an increasing role in the management of dysplasia within Barrett's and current data would favour the use of radiofrequency ablation compared with photodynamic therapy. Radiofrequency ablation has been shown to yield significantly fewer complications than photodynamic therapy and is very efficacious at eradicating both dysplasia and Barrett's itself. However, long-term follow-up data are still needed before radiofrequency ablation can be used in routine clinical care without the need for very careful post-treatment surveillance. More clinical trial data and in particular randomised controlled trials are required to assess whether or not the cancer risk is reduced in routine clinical practice.

Identification of predictive factors for early neoplasia in Barrett's esophagus after autofluorescence imaging: a stepwise multicenter structured assessment

BACKGROUND

Autofluorescence imaging is a novel imaging technique that may improve the detection of early neoplasia in Barrett's esophagus. Autofluorescence imaging is, however, associated with a 40% to 81% false-positive rate.

OBJECTIVE

Our purpose was to identify endoscopic features that may predict the presence of early neoplasia in autofluorescence-positive areas.

DESIGN

Descriptive and prospective cohort study.

SETTING

Tertiary referral centers for the detection and treatment of early Barrett's neoplasia.

PATIENTS AND METHODS

Patients undergoing autofluorescence endoscopy. High-quality images with autofluorescence imaging and white-light endoscopy were obtained with corresponding histologic study. A systematic image evaluation process was performed, including an unblinded orientation phase (10 areas), a blinded derivation phase, and a blinded validation phase by 5 international experts in autofluorescence imaging (80 areas). Subsequently the identified features were validated in a prospective pilot study.

MAIN OUTCOME MEASUREMENTS

Association between endoscopic features and presence of early neoplasia in autofluorescence-positive areas.

RESULTS

Autofluorescence intensity, proximity of gastric folds <1 cm, and different appearance on white-light endoscopy were independently associated with early neoplasia in autofluorescence-positive areas on multivariate analysis. The kappa values for interobserver agreement of these factors were moderate, ranging between 0.49 to 0.56. The association with autofluorescence intensity and different appearance on white-light endoscopy was confirmed in a prospective pilot study.

LIMITATION

Selected set of images from a high-risk population (tertiary referral center).

CONCLUSION

We found specific endoscopic features that were associated with early neoplasia in autofluorescence-positive areas. These findings can be used in future prospective studies to improve the accuracy of autofluorescence imaging without performing magnification endoscopy for detailed inspection of suspicious areas.

Diagnostic yield of methylene blue chromoendoscopy for detecting specialized intestinal metaplasia and dysplasia in Barrett's esophagus: a meta-analysis

BACKGROUND

The reported yield of methylene-blue (MB) chromoendoscopy targeted biopsy in detecting specialized intestinal metaplasia (SIM) and, more importantly, dysplasia in patients with Barrett's esophagus (BE) has shown variable results.

OBJECTIVE

To perform a meta-analysis of published studies for assessment of the diagnostic yield of techniques of chromoendoscopy compared with conventional 4-quadrant random biopsy (RB) in detection of SIM and dysplasia in patients with BE.

DESIGN

A literature search of the MEDLINE, EMBASE, and the Cochrane Databases was performed, along with a search of PubMed and a manual search of cross-references of eligible articles. Data on yield of both modalities were extracted and analyzed to estimate weighted incremental yield (IY) and 95% CIs of MB over RB using a fixed-effects or random-effects model, as appropriate, based on whether homogeneity or heterogeneity, respectively, was indicated by Cochrane's Q chi(2) test.

PATIENTS

A total of 450 patients with BE were reported in 9 studies included in the meta-analysis.

RESULTS

There was no significant IY with MB over RB for detection of SIM (IY 4%; 95% CI, -7% to 16%; 6 studies, n = 251), dysplasia (IY 9%; 95% CI, -1% to 20%; 9 studies, n = 450), and high-grade dysplasia and/or early cancer (IY 5%; 95% CI, -1% to 10%; 8 studies, n = 405).

LIMITATIONS

Only data on MB were analyzed because of limited availability of data for other chromoendoscopy dyes, minor variations in inclusion and exclusion criteria, and the small sample size, and because differences in application technique could have led to an underestimation of the diagnostic yield of MB chromoendoscopy.

CONCLUSION

The technique of MB chromoendoscopy has only a comparable yield with RB for the detection of SIM and dysplasia during endoscopic evaluation of patients with BE.

Chromoendoscopy

Chromoendoscopy involves the use of stains or dyes during endoscopy to improve the visualization and characterization of the gastrointestinal mucosa. Its main clinical application is the detection of dysplasia or early cancer of the gastrointestinal tract in individuals with pre-malignant conditions or hereditary and environmental factors that predispose them to cancer. The utility of chromoendoscopy has been mostly studied in squamous cell carcinoma of the esophagus, Barrett's esophagus, gastric cancer, colorectal polyps, and chronic ulcerative colitis. Although chromoendoscopy has been shown to be feasible and safe, several limitations have prevented its widespread use in endoscopy. Despite this, chromoendoscopy remains a useful adjunct to standard white light endoscopy in the visualization of mucosal lesions, which may potentially improve tissue diagnosis and impact patient care.

Barrett's oesophagus

Barrett's oesophagus is a metaplastic change of the lining of the oesophagus, such that the normal squamous epithelium is replaced by specialised or intestinalised columnar epithelium. The disorder seems to be a complication of chronic gastro-oesophageal reflux disease, although asymptomatic individuals might also be affected, and it is a risk factor for the development of oesophageal adenocarcinoma, a cancer with rapidly increasing incidence in developed societies. We review the presentation, epidemiology, and risk factors for this condition. We discuss the molecular changes necessary for the development of Barrett's oesophagus and its progression to cancer, and new strides in both the endoscopic detection of the lesion and the treatment of dysplastic disease. Also, we assess the effectiveness of efforts to screen patients at risk of Barrett's oesophagus, and whether such efforts avert cancer death. We conclude with a discussion of future directions for research, focusing on treatment of early neoplasia, and modifications of current practices to show our evolving understanding of this condition.

Optimal approach to obtaining mucosal biopsies for assessment of inflammatory disorders of the gastrointestinal tract

Endoscopic evaluation and mucosal biopsy analysis have assumed important roles in the clinical management of patients with symptoms related to the gastrointestinal tract. Several common inflammatory diseases, including eosinophilic esophagitis, Barrett's esophagus, Helicobacter pylori infection, celiac disease, lymphocytic colitis, collagenous colitis, and inflammatory bowel disease, may display a patchy or discontinuous distribution and, thus, multiple mucosal samples may be required to obtain diagnostic tissue in some cases. Not surprisingly, clinicians and pathologists are increasingly challenged to determine the optimum number of procedures and tissue samples necessary to detect, or exclude, the presence of inflammatory disorders of the gastrointestinal tract. Unfortunately, clinical practice varies widely with respect to tissue sample procurement in the evaluation of these disorders, particularly when the endoscopic appearance of the gastrointestinal mucosa is normal or shows only minimal changes. Guidelines concerning the appropriate number of tissue samples are well established for some diseases, such as Barrett's esophagus and chronic gastritis, but are not clear in other instances. The purpose of this review is to discuss the available literature pertaining to appropriate endoscopic sampling in the assessment of medical diseases of the gastrointestinal tract, and to develop recommendations regarding the clinical evaluation of common gastrointestinal disorders.

Barrett's esophagus: where do we stand?

Barrett's esophagus (BE) is a precursor for esophageal adenocarcinoma, which has an increased incidence rate over the last few decades. Its importance stems from the poor five-year survival of esophageal adenocarcinoma and current data that suggest a survival benefit when surveillance programs are implemented. In this review, we will cover the pathophysiology and natural history of BE and the different endoscopic findings. The prevalence of BE in different geographic areas and the incidence of high-grade dysplasia and adenocarcinoma in this patient population is reviewed. Recent recommendation for screening and surveillance of BE has been covered in this review as well as the efficacy of nonconventional imaging modalities and endoscopic ablation therapies.

Novel imaging modalities in the detection of oesophageal neoplasia

The prognosis of oesophageal neoplasia is dependent on the stage of the disease at the time of detection. Early lesions have an excellent prognosis in contrast to more advanced stages that usually have a dismal prognosis. Therefore, the early detection of these lesions is of the utmost importance. In recent years, several new techniques have been introduced to improve the endoscopic detection of early lesions. The most important improvement, in general, has been the introduction of high-resolution/high-definition endoscopy into daily clinical practice. The value of superimposing techniques such as chromoendoscopy, narrow band imaging and computed virtual chromoendoscopy onto high-resolution/high-definition endoscopy will have to be proven in randomised cross-over trials comparing these techniques with standard techniques. Important future adjuncts to white-light endoscopy serving as 'red-flag' techniques for the detection of early neoplasia may be broad field functional imaging techniques such as video autofluorescence endoscopy. In addition, real-time histopathology during endoscopy has become possible with endocytoscopy and confocal endomicroscopy. The clinical value of these techniques needs to be ascertained in the coming years.

Prospective, controlled tandem endoscopy study of narrow band imaging for dysplasia detection in Barrett's Esophagus

BACKGROUND & AIMS

High-resolution endoscopy with narrow band imaging (NBI) enhances the visualization of mucosal glandular and vascular structures. This study assessed whether narrow band targeted biopsies could detect advanced dysplasia using fewer biopsy samples compared with standard resolution endoscopy.

METHODS

We conducted a prospective, blinded, tandem endoscopy study in a tertiary care center with 65 patients with Barrett's esophagus undergoing evaluation for previously detected dysplasia. Standard resolution endoscopy was used first to detect visible lesions. Narrow band endoscopy was then used by another gastroenterologist to detect and biopsy areas suspicious for dysplasia. The lesions initially detected by standard resolution endoscopy were then disclosed and biopsied, after biopsy of the lesions targeted with NBI. Finally, random 4-quadrant biopsies were taken throughout the segment of Barrett's mucosa.

RESULTS

Higher grades of dysplasia were found by NBI in 12 patients (18%), compared with no cases (0%) in whom standard resolution white light endoscopy with random biopsy detected a higher grade of histology (P < .001). Correspondingly, narrow band directed biopsies detected dysplasia in more patients (n = 37; 57%) compared with biopsies taken using standard resolution endoscopy (n = 28; 43%). In addition, more biopsies were taken using standard resolution endoscopy with random biopsy compared with narrow band targeted biopsies (mean 8.5 versus 4.7; P < .001).

CONCLUSIONS

In patients evaluated for Barrett's esophagus with dysplasia, NBI detected significantly more patients with dysplasia and higher grades of dysplasia with fewer biopsy samples compared with standard resolution endoscopy.

Chromoendoscopy and narrow-band imaging compared with high-resolution magnification endoscopy in Barrett's esophagus

BACKGROUND & AIMS

The aim of this study was to compare magnified still images obtained with high-resolution white light endoscopy, indigo carmine chromoendoscopy, acetic acid chromoendoscopy, and narrow-band imaging to determine the best technique for use in Barrett's esophagus.

METHODS

We obtained magnified images from 22 areas with the 4 aforementioned techniques. Seven endoscopists with no specific expertise in Barrett's esophagus or advanced imaging techniques and 5 international experts in this field evaluated these 22 areas for overall image quality, mucosal image quality, and vascular image quality. In addition, the regularity of mucosal and vascular patterns and the presence of abnormal blood vessels were evaluated, and this was correlated with histology.

RESULTS

The interobserver agreement for the 3 features of mucosal morphology with white light images ranged from kappa = 0.51 (95% confidence interval [CI]: 0.46-0.55) to kappa = 0.53 (95% CI: 0.50-0.57) for all observers, from kappa = 0.43 (95% CI: 0.33-0.54) to kappa = 0.53 (95% CI: 0.41-0.64) for experts, and from kappa = 0.51 (95% CI: 0.15-0.33) to kappa = 0.64 (95% CI: 0.58-0.70) for nonexperts. The interobserver agreement in these groups did not improve by adding one of the enhancement techniques. The yield for identifying early neoplasia with white light images was 86% for all observers, 90% for experts, and 84% for nonexperts. The addition of enhancement techniques did not improve the yield neoplasia.

CONCLUSIONS

The addition of indigo carmine chromoendoscopy, acetic acid chromoendoscopy, or narrow-band imaging to white light images did not improve interobserver agreement or yield identifying early neoplasia in Barrett's esophagus.

A randomized comparison of methylene blue-directed biopsy versus conventional four-quadrant biopsy for the detection of intestinal metaplasia and dysplasia in patients with long-segment Barrett's esophagus

OBJECTIVES

Methylene blue (MB) selectively stains specialized intestinal metaplasia (SIM) and may assist in surveying a columnar-lined esophagus for Barrett's esophagus associated dysplasia.

METHODS

This is a prospective, randomized crossover study comparing 4-quadrant random biopsies (4QB) versus MB-directed biopsies for the detection of SIM and dysplasia in 48 patients with long segment Barrett's esophagus (LSBE). Patients randomly underwent two endoscopies over a 4-wk time period with either 4QB or MB-directed biopsies as their first or second exam. Our aim was to correlate stain intensity with histology.

RESULTS

The sensitivity of MB for SIM and dysplasia was 75.2% and 83.1%, respectively. The yield of 4QB for identifying nondysplasia SIM was 57.6% (523/917) and for dysplasia was 12% (111/917). Dark staining was significantly associated with histologic grade (P < 0.007). The final diagnosis was correct in 43 (90%) patients using MB and in 45 (94%) using 4QB. The 4QB technique missed dysplasia in 3 of 21 patients while MB biopsies missed dysplasia in 5 of 21 patients. The discordance between the two techniques was not significant (P= 0.727, McNemar's test). The mean number of biopsies taken during 4QB was 18.92 +/- 6.36 and with MB was 9.23 +/- 2.89 (P < 0.001).

CONCLUSION

MB requires significantly fewer biopsies than 4QB to evaluate for SIM and dysplasia. Dark staining correlates more with HGD than LGD in our experience. While MB is not more accurate than 4QB, MB may help to define areas to target for biopsy during surveillance endoscopy in patients with LSBE.

Methylene blue dye--a safe and effective alternative for sentinel lymph node localization

Sentinel lymph node (SLN) biopsy has emerged as an effective diagnostic tool in axillary staging in breast cancer. The commonly used technique employs isosulfan blue/patent blue V combined with radioactive colloid tracer. Methylene blue (MB) is a less expensive and readily available alternative dye. The study evaluated the safety and efficacy of MB in SLN localization. A retrospective study of 329 patients with early breast cancer who had SLN localization as part of an ethically approved prospective evaluation study of SLN localization technique was carried out. Lymph node positive, tumors >2 cm on clinical and radiological evaluation, those with previous breast and axillary surgery, neo-adjuvant chemotherapy were excluded from the study. One hundred seventy three patients underwent SLN localization using 1 mL of 1% MB, and a combined MB-radio colloid tracer technique was used in the other 156 patients. Allocation to the groups was by simple randomization. Injection of the dye and radioisotope was into the subdermal plane in the sub-areolar region. Patients underwent breast conservation surgery or mastectomy with SLN directed four node axillary sampling +/- axillary clearance. The lymph node was examined by standard microscopy. There were no reported complications with the use of MB aside from temporary tattooing. The technique failed in eight patients giving an identification rate of 97.6%. Ten of the 258 (3.9%) patients had false-negative SLN, with negative predictive value of 96.1%, sensitivity of predicting further axillary disease of 73%, specificity of 87.3%, and overall accuracy of 85.7%. Reported adverse reaction to isosulfan blue/patent blue V varied from minor to severe anaphylactic reactions (1-3%) requiring vigorous resuscitation. Subdermal sub-areolar injection of MB is safe and effective readily available dye for SLN localization in axillary staging of breast cancer with no major adverse reaction.

Barrett's Esophagus: Diagnosis, Screening, Surveillance, and Controversies

Barrett's esophagus (BE) is a frequent complication of gastroesophageal reflux disease, an acquired condition resulting from persistent mucosal injury to the esophagus. The incidence of Barrett's metaplasia and Barrett's adenocarcinoma has been increasing, but the prognosis of Barrett's adenocarcinoma is worse because individuals present at a late stage. Attempts have been made to intervene at early stage using surveillance programmes, although proof of efficacy of endoscopic surveillance is lacking. There is much to be learned about BE. Whether adequate control of gastroesophageal reflux early in the disease alters the natural history of Barrett's change once it has developed remains unanswered. Thus there is great need for carefully designed large randomised controlled trials to address these issues in order to determine how best to manage patients with BE. The AspECT and BOSS clinical trials proride this basis.