A feasibility trial of narrow band imaging endoscopy in patients with gastroesophageal reflux disease

Latin American consensus on diagnosis of gastroesophageal reflux disease

BACKGROUND

Diagnosing gastroesophageal reflux disease (GERD) can be challenging given varying symptom presentations, and complex multifactorial pathophysiology. The gold standard for GERD diagnosis is esophageal acid exposure time (AET) measured by pH-metry. A variety of additional diagnostic tools are available. The goal of this consensus was to assess the individual merits of GERD diagnostic tools based on current evidence, and provide consensus recommendations following discussion and voting by experts.

METHODS

This consensus was developed by 15 experts from nine countries, based on a systematic search of the literature, using GRADE (grading of recommendations, assessment, development and evaluation) methodology to assess the quality and strength of the evidence, and provide recommendations regarding the diagnostic utility of different GERD diagnosis tools, using AET as the reference standard.

KEY RESULTS

A proton pump inhibitor (PPI) trial is appropriate for patients with heartburn and no alarm symptoms, but nor for patients with regurgitation, chest pain, or extraesophageal presentations. Severe erosive esophagitis and abnormal reflux monitoring off PPI are clearly indicative of GERD. Esophagram, esophageal biopsies, laryngoscopy, and pharyngeal pH monitoring are not recommended to diagnose GERD. Patients with PPI-refractory symptoms and normal endoscopy require reflux monitoring by pH or pH-impedance to confirm or exclude GERD, and identify treatment failure mechanisms. GERD confounders need to be considered in some patients, pH-impedance can identify supragrastric belching, impedance-manometry can diagnose rumination.

CONCLUSIONS

Erosive esophagitis on endoscopy and abnormal pH or pH-impedance monitoring are the most appropriate methods to establish a diagnosis of GERD. Other tools may add useful complementary information.

Esophageal Mucosal Resistance in Reflux Esophagitis: What We Have Learned So Far and What Remains to Be Learned

Gastroesophageal reflux disease (GERD) has the highest prevalence among diseases of the digestive system and is characterized by a significant decrease in patients' quality of life, comparable to arterial hypertension and coronary heart disease. One in every ten cases of reflux esophagitis leads to the formation of Barrett's esophagus, which is associated with a high risk of esophagus adenocarcinoma. The key factors determining the progression of the disease are the frequency and duration of the reflux of the stomach's contents. As a result, refluxate, which includes hydrochloric acid, pepsin, and, in the case of concomitant duodeno-gastric reflux, bile acids and lysolecithin, is thrown into the overlying sections of the digestive tract. At the same time, in addition to aggression factors, it is necessary to take into account the state of resistance in the esophageal mucosa to the effects of aggressive refluxate molecules. This review was prepared using systematized data on the protective properties of the esophageal mucosa and modern methods to assess the mucosal barrier in reflux esophagitis. Lesions of the epithelial barrier structure in the esophagus are recognized as the main pathogenetic factor in the development of reflux esophagitis and are a potentially significant therapeutic target in the treatment of GERD and Barrett's esophagus. This article presents the characteristics of the esophageal mucosal barrier and the protective mechanisms of the esophagus's mucous membrane in conditions of gastroesophageal reflux. Diagnostic approaches for assessing the course of reflux esophagitis are described for both histological criteria and the possibility of a comprehensive assessment of the state of mucins, tight-junction proteins, and the proliferative activity of the mucosa, including under the conditions of ongoing therapy.

Usefulness of Endoscopy for the Detection and Diagnosis of Primary Esophageal Motility Disorders and Diseases Relating to Abnormal Esophageal Motility

Esophagogastroduodenoscopy (EGD) is performed to rule out organic diseases in the diagnosis of esophageal motility disorders (EMDs). Abnormal endoscopic findings can be observed during EGD, which indicate the presence of EMDs. Several endoscopic findings at both the esophagogastric junction and esophageal body that are related to EMDs have been reported. Gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EoE) could be detected during EGD, and these diseases are often associated with abnormal esophageal motility. Image-enhanced endoscopy (IEE) could improve the detection of these diseases during EGD. Although no report has been published previously on the potential usefulness of IEE in the endoscopic diagnosis of EMDs, IEE can be used to detect disorders that can be associated with abnormal esophageal motility.

An Improved Endoscopic Automatic Classification Model for Gastroesophageal Reflux Disease Using Deep Learning Integrated Machine Learning

Gastroesophageal reflux disease (GERD) is a common digestive tract disease, and most physicians use the Los Angeles classification and diagnose the severity of the disease to provide appropriate treatment. With the advancement of artificial intelligence, deep learning models have been used successfully to help physicians with clinical diagnosis. This study combines deep learning and machine learning techniques and proposes a two-stage process for endoscopic classification in GERD, including transfer learning techniques applied to the target dataset to extract more precise image features and machine learning algorithms to build the best classification model. The experimental results demonstrate that the performance of the GerdNet-RF model proposed in this work is better than that of previous studies. Test accuracy can be improved from 78.8% ± 8.5% to 92.5% ± 2.1%. By enhancing the automated diagnostic capabilities of AI models, patient health care will be more assured.

Advanced Endoscopy for Benign Esophageal Disease: A Review Focused on Non-Erosive Reflux Disease and Eosinophilic Esophagitis

Advanced endoscopy (AVE) techniques include image-enhanced endoscopy methods, such as narrow-band imaging (NBI), and types of microscopic endoscopy, such as endocytoscopy. In the esophagus, AVE first showed diagnostic utility in the diagnosis of superficial esophageal cancer and was then applied to inflammatory disease. This review focuses on non-erosive reflux disease (NERD) and eosinophilic esophagitis (EoE), which sometimes show no abnormal findings on standard white light endoscopy alone. Studies have demonstrated that advanced endoscopy, including NBI magnification endoscopy and endocytoscopy, improved the diagnostic performance of white-light endoscopy alone for NERD and EoE. In this review, we explain why advanced endoscopy is needed for the diagnosis of these esophageal inflammatory diseases, summarize the study results, and discuss future perspectives.

Narrow-band imaging for the diagnosis of nonerosive reflux disease: an international, multicenter, randomized controlled trial

BACKGROUND AND AIMS

We examined the accuracy of narrow-band imaging (NBI) findings in nonerosive reflux disease (NERD) patients compared with control subjects and the impact of proton pump inhibitor (PPI) therapy on these mucosal changes in a multicenter, double-blind, randomized controlled trial.

METHODS

NERD patients (typical symptoms using a validated GERD questionnaire, absence of erosive esophagitis, and abnormal 48-hour pH study) and control subjects underwent high-definition white-light endoscopy followed by NBI and biopsy sampling of the distal esophagus. Then, NERD patients were randomized to esomeprazole 40 mg/day or placebo for 8 weeks, followed by repeat endoscopy. The presence of distal esophageal mucosal changes on NBI were recorded at baseline and after treatment: intrapapillary capillary loops (IPCLs; number, dilation, and tortuosity), microerosions, increased vascularity, columnar islands, and ridge/villous pattern (RVP) above the squamocolumnar junction.

RESULTS

Of 122 screened, 21 NERD and 21 control subjects were identified (mean age, 49.5 ± 14.6 years; 62% men; and 85% white). The combination of IPCL tortuosity, RVP, and microerosions (62% vs 19%, P < .05) had a high specificity (86%) and moderate sensitivity (60%) for NERD with an area under the curve of .74. In 10 NERD patients treated with PPIs, resolution of microerosions was most significant (P = .047) compared with placebo (n = 11). RVP resolved in all NERD patients after therapy (P = .02) and correlated with acid exposure time (P = .004). Papillary length (P = .02) and basal cell thickness (P = .02) significantly correlated with a combination of IPCL tortuosity, RVP, and microerosions.

CONCLUSIONS

In this randomized controlled trial, RVP on NBI demonstrated a high specificity, correlated with acid exposure time, and improved with PPI therapy, suggesting that it could be used as a surrogate marker for diagnosis of NERD. (Clinical trial registration number: NCT02081404.).

Definition of Mucosal Breaks in the Era of Magnifying Endoscopy with Narrow-Band Imaging

Background

Gastroesophageal reflux disease is diagnosed endoscopically based on the presence of mucosal breaks. However, mucosal breaks can be judged differently depending on the endoscopist, even in the same image. We investigated how narrow-band imaging (NBI) and magnified endoscopy affect the judgment of mucosal breaks.

Methods

A total of 43 consecutive patients were enrolled who had suspected mucosal breaks on white-light images (WLI) and underwent nonmagnified NBI (N-NBI) and magnified NBI (M-NBI) by a single endoscopist. From WLI, N-NBI, and M-NBI, 129 image files were created. Eight endoscopists reviewed the image files and judged the presence of mucosal breaks.

Results

The 8 endoscopists determined mucosal breaks were present in 79.4 ± 9.5% (67.4%-93.0%) on WLI, and 76.7 ± 12.7% (53.5%-90.7%) on N-NBI. However, the percentage of mucosal breaks on M-NBI was significantly lower at 48.8 ± 17.0% (18.6%-65.1%) (p < 0.05). Intraclass correlation between observers was 0.864 (95% CI 0.793-0.918) for WLI and 0.863 (95% CI 0.791-0.917) for N-NBI but was lower for M-NBI at 0.758 (95% CI 0.631-0.854).

Conclusion

Rates of detection and agreement for mucosal breaks on WLI and N-NBI were high among endoscopists. However, these rates were lower on M-NBI.

The role of endoscopy in the management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disease that may cause a huge economic burden. Endoscopy is performed not only to rule out other organic diseases but also to diagnose reflux esophagitis or Barrett's esophagus. Non‐erosive GERD (non‐erosive reflux disease [NERD]) is called endoscopy‐negative GERD; however, GERD‐related findings could be obtained through histological assessment, image‐enhanced endoscopy, and new endoscopic modalities in patients with NERD. Moreover, endoscopy is useful to stratify the risk for the development of GERD. In addition, endoscopic treatments have been developed. These techniques could significantly improve patients’ quality of life as well as symptoms.

Systematic review with meta-analysis: artificial intelligence in the diagnosis of oesophageal diseases

BACKGROUND

Artificial intelligence (AI) has recently been applied to endoscopy and questionnaires for the evaluation of oesophageal diseases (ODs).

AIM

We performed a systematic review with meta-analysis to evaluate the performance of AI in the diagnosis of malignant and benign OD.

METHODS

We searched MEDLINE, EMBASE, EMBASE Classic and the Cochrane Library. A bivariate random-effect model was used to calculate pooled diagnostic efficacy of AI models and endoscopists. The reference tests were histology for neoplasms and the clinical and instrumental diagnosis for gastro-oesophageal reflux disease (GERD). The pooled area under the summary receiver operating characteristic (AUROC), sensitivity, specificity, positive and negative likelihood ratio (PLR and NLR) and diagnostic odds ratio (DOR) were estimated.

RESULTS

For the diagnosis of Barrett's neoplasia, AI had AUROC of 0.90, sensitivity 0.89, specificity 0.86, PLR 6.50, NLR 0.13 and DOR 50.53. AI models' performance was comparable with that of endoscopists (P = 0.35). For the diagnosis of oesophageal squamous cell carcinoma, the AUROC, sensitivity, specificity, PLR, NLR and DOR were 0.97, 0.95, 0.92, 12.65, 0.05 and DOR 258.36, respectively. In this task, AI performed better than endoscopists although without statistically significant differences. In the detection of abnormal intrapapillary capillary loops, the performance of AI was: AUROC 0.98, sensitivity 0.94, specificity 0.94, PLR 14.75, NLR 0.07 and DOR 225.83. For the diagnosis of GERD based on questionnaires, the AUROC, sensitivity, specificity, PLR, NLR and DOR were 0.99, 0.97, 0.97, 38.26, 0.03 and 1159.6, respectively.

CONCLUSIONS

AI demonstrated high performance in the clinical and endoscopic diagnosis of OD.

Electronic chromo-endoscopy: technical details and a clinical perspective

Precise endoscopic assessment is necessary to detect neoplastic changes in an early stage. Electronic or virtual chromo-endoscopy (ECE) is an alternative to conventional dye-based chromo-endoscopy which markedly improves capillary pattern and hence can detect micro-vessel morphological changes of early neoplasia to target biopsies and aid in diagnosis. The clinical significance increased after the advent of endoscopic treatment modalities like ESD/EMR which requires precise delineation of extent and depth of lesion. Most of the studies have used narrow-band imaging (NBI) (Olympus Medical Systems Tokyo, Japan), although data from i-SCAN (PENTAX Endoscopy, Tokyo, Japan) and flexible spectral imaging color enhancement (FICE) (Fujinon, Fujifilm Medical Co, Saitama, Japan) are emerging. Electronic chromo-endoscopy is convenient compared to dye-based chromo-endoscopy in the sense that it is available at the push of a button in endoscope and reduces procedure time substantially with comparable efficacy. Scope of this review is to discuss available electronic chromo-endoscopy modalities and their role in the diagnosis, surveillance, and management of early GI neoplasia.

Advanced Endoscopic Imaging and Interventions in GERD: An Update and Future Directions

Gastroesophageal reflux disease (GERD) is one of the most common gastrointestinal diseases encountered in primary care and gastroenterology clinics. Most cases of GERD can be diagnosed based on clinical presentation and risk factors; however, some patients present with atypical symptoms, which can make diagnosis difficult. An esophagogastroduodenoscopy can be used to assist in diagnosis of GERD, though only half of these patients have visible endoscopic findings on standard white light endoscopy. This led to the development of new advanced endoscopic techniques that enhanced the diagnosis of GERD and related complications like squamous cell dysplasia, Barrett's esophagus, and early esophageal adenocarcinoma. This is conducted by improved detection of subtle irregularities in the mucosa and vascular structures through optical biopsies in real-time. Management of GERD includes lifestyle modifications, pharmacological therapy, endoscopic and surgical intervention. Minimally invasive endoscopic intervention can be an option in selected patients with small hiatal hernia and without complications of GERD. These endoscopic interventions include endoscopic fundoplication, endoscopic mucosal resection techniques, ablative techniques, creating mechanical barriers, and suturing and stapling devices. As these new advanced endoscopic techniques are emerging, data surrounding the indications, advantages and disadvantages of these techniques need a thorough understanding.

Characteristics of superficial esophageal squamous cell carcinomas undetectable with narrow-band imaging endoscopy

Background

The detection rate of narrow-band imaging (NBI) for superficial esophageal squamous cell carcinoma (SESCC), including high-grade intraepithelial neoplasia, is significantly higher than that of white-light endoscopy. However, there are SESCCs that are undetectable by NBI but detectable by Lugol chromoendoscopy (LCE) and the characteristics of these SESCCs are still unknown. Thus, this study aimed to clarify the characteristics of SESCC that are undetectable using NBI.

Methods

Patients with current SCC or a history of SCC in the head and neck or in the esophagus were enrolled. The inspection of the esophagus was initiated by NBI, followed by LCE. Biopsies were taken of all suspected SESCC lesions during NBI observation and Lugol-voiding lesions (LVLs) that were irregularly shaped and >5 mm and/or pink in color during LCE observation. The characteristics of SESCC that were undetectable with NBI were statistically analysed.

Results

Overall, 147 lesions in 105 cases were histologically diagnosed as SESCC. Twenty in 15 cases were NBI-undetectable lesions, all of which were macroscopic flat type (0-IIb). The median sizes of the NBI-undetectable lesions and NBI-detectable lesions were both 15 mm (P = 0.47). Multivariate analysis revealed independent factors for NBI-undetectable lesions such as numerous irregularly shaped LVLs (odds ratio [OR]: 4.94, 95% confidence interval [CI]: 1.39–17.5, P < 0.05) and anterior wall position (OR: 4.99, 95% CI: 1.58–15.8, P < 0.05).

Conclusions

The detection of SESCCs with NBI is challenging when lesions are morphologically completely flat, in cases with numerous irregularly shaped LVLs, and if located at the anterior wall.

Multichannel impedance monitoring for distinguishing nonerosive reflux esophagitis with minor changes on endoscopy in children

Objectives:

There are reports describing the relationship between baseline impedance level and esophageal mucosal integrity at endoscopy, such as erosive and nonerosive reflux esophagitis. However, many children with symptoms of gastroesophageal reflux disease have normal findings or minor changes on esophagogastroduodenoscopy. We aimed to examine whether modest changes at esophagogastroduodenoscopy can be evaluated and correlated with esophageal multichannel intraluminal impedance monitoring.

Methods:

Patients (ages 0–17 years) with upper gastrointestinal symptoms who underwent combined esophagogastroduodenoscopy and multichannel intraluminal impedance monitoring at the Women’s and Children’s Hospital, Adelaide, Australia, between 2014 and 2016 were retrospectively studied and the following data were collected and used for analysis: demographics, multichannel intraluminal impedance data, included baseline impedance. Endoscopic findings were classified by modified Los Angeles grading, Los Angeles N as normal, Los Angeles M as with minimal change such as the erythema, pale mucosa, or friability of the mucosa following biopsy. Patients on proton pump inhibitor were excluded.

Results:

Seventy patients (43 boys; 61%) were enrolled with a mean age of 7.9 years (range 10 months to 17 years). Fifty-one patients (72.9%) were allocated to Los Angeles N, while Los Angeles M was evident in 19 patients (27.1%). Statistically significant differences were observed in the following parameters: frequency of acid and nonacid reflux and baseline impedance in channels 5 and 6. The median values of the data were 18.3 episodes, 16.0 episodes, 2461.0 Ω, 2446.0 Ω in Los Angeles N, 36.0 episodes, 31.0 episodes, 2033.0 Ω, 2009.0 Ω in Los Angeles M, respectively.

Conclusion:

Lower baseline impedance is helpful in predicting minimal endoscopic changes in the lower esophagus. A higher frequency of acid and nonacid reflux episodes was also predictive of minimal endoscopic change in the lower esophagus.

Relationship Between Gastroesophageal Reflux Disease and Endoscopic Finding "Iodine-Unstained Streak"

Background

Esophagogastroduodenoscopy (EGD) with iodine stain is a useful and diffused method for diagnosing esophageal cancer. We can perform the procedure easily with endoscopic system which does not comprise image-enhanced endoscopy. Several studies advocated that iodine-unstained streaks are a characteristic finding of gastroesophageal reflux disease (GERD). However, there are only a few reports about the subject. In this study, we investigated the usefulness of iodine chromoendoscopy for GERD consultation.

Methods

The study was conducted with 154 GERD cases in which EGD with iodine stain to the esophagus was performed. For the 154 cases, we analyzed the existence of reflux esophagitis finding and iodine-unstained streaks. In 47 GERD cases (proton pump inhibitor (PPI): 45 cases, histamine H2-receptor antagonist (H2-RA): two cases) where medication was started after EGD, we examined predictive factors of the symptom improvement such as sex, age, weight, reflux esophagitis finding, and iodine-unstained streak.

Results

An iodine-unstained streak was observed in 50/154 cases (32.5%). For 50 cases with iodine-unstained streak, there were only 24/50 cases (48.0%) that had both reflux esophagitis findings (≥ Los Angeles classification: grade M) and an iodine-unstained streak. For 47 cases in which medication was started, 34 cases showed improvement in their symptoms, and 13 cases did not show improvement. An iodine-unstained streak was observed more often in “Improved” group rather than in “Not improved” group (P < 0.01). When we supposed an iodine-unstained streak to be the predictive factor of the medication effect for GERD, sensitivity was 61.8% and specificity was 84.6%.

Conclusions

No erosion was often found in the GERD cases without reflux esophagitis, and iodine-unstained streak was observed more often in “Improved” group rather than in “Not improved” group. We think that iodine-unstained streak can be useful for diagnosing of GERD and predictive factor of the medication effect.

Linked color imaging improves visibility of reflux esophagitis

Background

With more prevalent gastroesophageal reflux disease comes increased cases of Barrett's esophagus and esophageal adenocarcinoma. Image-enhanced endoscopy using linked-color imaging (LCI) differentiates between mucosal colors. We compared LCI, white light imaging (WLI), and blue LASER imaging (BLI) in diagnosing reflux esophagitis (RE).

Methods

Consecutive RE patients (modified Los Angeles [LA] classification system) who underwent esophagogastroduodenoscopy using WLI, LCI, and BLI between April 2017 and March 2019 were selected retrospectively. Ten endoscopists compared WLI with LCI or BLI using 142 images from 142 patients. Visibility changes were scored by endoscopists as follows: 5, improved; 4, somewhat improved; 3, equivalent; 2, somewhat decreased; and 1, decreased. For total scores, 40 points was considered improved visibility, 21–39 points was comparable to white light, and < 20 points equaled decreased visibility. Inter- and intra-rater reliabilities (Intra-class Correlation Coefficient [ICC]) were also evaluated. Images showing color differences (ΔE*) and L* a* b* color values in RE and adjacent esophageal mucosae were assessed using CIELAB, a color space system.

Results

The mean age of patients was 67.1 years (range: 27–89; 63 males, 79 females). RE LA grades observed included 52 M, 52 A, 24 B, 11 C, and 3 D. Compared with WLI, all RE cases showed improved visibility: 28.2% (40/142), LA grade M: 19.2% (10/52), LA grade A: 34.6% (18/52), LA grade B: 37.5% (9/24), LA grade C: 27.3% (3/11), and LA grade D: 0% (0/3) in LCI, and for all RE cases: 0% in BLI. LCI was not associated with decreased visibility. The LCI inter-rater reliability was “moderate” for LA grade M and “substantial” for erosive RE. The LCI intra-rater reliability was “moderate–substantial” for trainees and experts. Color differences were WLI: 12.3, LCI: 22.7 in LA grade M; and WLI: 18.2, LCI: 31.9 in erosive RE (P < 0.001 for WLI vs. LCI).

Conclusion

LCI versus WLI and BLI led to improved visibility for RE after subjective and objective evaluations. Visibility and the ICC for minimal change esophagitis were lower than for erosive RE for LCI. With LCI, RE images contrasting better with the surrounding esophageal mucosa were more clearly viewed.

Endoscopic Diagnosis and Treatment of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a deadly disease, partly because it is often diagnosed late in disease stage. An accurate early diagnosis by endoscopy could detect advanced carcinoma as well as curable dysplasia and early ESCC. This could save patients from incurable advanced malignancy. Important progress has been made in high-quality endoscopic diagnosis, including magnifying endoscopy, narrowband imaging, and other image enhancement, as well as in techniques in endoscopic resection. These emerging techniques will aid the early diagnosis of ESCC that lead to higher chance of curing the cancer.

Indian consensus on gastroesophageal reflux disease in adults: A position statement of the Indian Society of Gastroenterology

The Indian Society of Gastroenterology developed this evidence-based practice guideline for management of gastroesophageal reflux disease (GERD) in adults. A modified Delphi process was used to develop this consensus containing 58 statements, which were generated by electronic voting iteration as well as face-to-face meeting and review of the supporting literature primarily from India. These statements include 10 on epidemiology, 8 on clinical presentation, 10 on investigations, 23 on treatment (including medical, endoscopic, and surgical modalities), and 7 on complications of GERD. When the proportion of those who voted either to accept completely or with minor reservation was 80% or higher, the statement was regarded as accepted. The prevalence of GERD in India ranges from 7.6% to 30%, being  < 10% in most population studies, and higher in cohort studies. The dietary factors associated with GERD include use of spices and non-vegetarian food. Helicobacter pylori is thought to have a negative relation with GERD; H. pylori negative patients have higher grade of symptoms of GERD and esophagitis. Less than 10% of GERD patients in India have erosive esophagitis. In patients with occasional or mild symptoms, antacids and histamine H₂ receptor blockers (H2RAs) may be used, and proton pump inhibitors (PPI) should be used in patients with frequent or severe symptoms. Prokinetics have limited proven role in management of GERD.

The utility of narrow band imaging in endoscopic diagnosis of laryngopharyngeal reflux

OBJECTIVE

This study assessed the utility of narrow band imaging (NBI) in patients with symptoms of laryngopharyngeal reflux (LPR) and tried to quantitatively evaluate the signs found under the NBI Laryngoscope.

METHODS

Patients with and without LPR symptoms completed reflux symptom index (RSI) questionnaires prior to enrolment. The throat was examined by standard white light endoscopy followed by NBI. LPR status was determined using the reflux finding score and the RSI. Laryngoscope images and videos from 70 subjects with LPR and 70 control subjects without LPR were obtained. Features seen only by NBI were compared between the two groups. Then the RGB values of the throat mucosa of the two groups were measured by Photoshop software, and finally statistical analysis was performed.

RESULTS

In total, 140 patients were eligible for final analysis (LPR group mean age = 50.0, 47 males; control group mean age = 44.8, 45 males). A significantly higher proportion of patients with LPR had increased vascularity, green spots, contact ulcers and granulomas. Of these, increased vascularity and green spots can only be found under NBI, and the prevalence rates in the LPR group were found to be 92.8% and 88.6% (P < 0.05), respectively. In the control group, the prevalence rates of increased vascularity and green spots were 21.4% and 7.1%, respectively (P < 0.05). The RGB value of the LPR group was generally higher than that of the control group. The difference is statistically significant (P < 0.05).

CONCLUSION

LPR presents vascularity and green spots with high specificity and sensitivity under NBI which can play a role in the auxiliary diagnosis of LPR.

Detection of minimal mucosal esophageal lesions in non-erosive gastroesophageal reflux disease using optical enhancement plus optical magnification

Background and study aims  The aim of this study was to evaluate the diagnostic yield of endoscopy using optical enhancement (OE system) with optical magnification to predict reflux in non-erosive reflux disease (NERD) patients. Patients and methods  A prospective, non-randomized, single-blind study was performed from September 2015 to January 2016. Participants suffered from gastroesophageal reflux disease (GERD) symptoms and were assigned to the NERD group or the non-reflux disease control group based on endoscopic findings and a 24-hour pH-impedance-monitoring test. Endoscopy using the OE system with optical magnification was performed in all patients to detect minimal mucosal esophageal lesions (MMEL), specifically abnormalities in the numbers, dilation, and tortuosity of intrapapillary capillary loops (IPCLs). Biopsies were obtained from each esophageal segment, and diagnoses from images were compared to diagnoses of reflux and inflammation using 24-hour pH-impedance monitoring and histology, respectively. Results  Fifty-seven patients were included (36 in the NERD group, 21 in the control group). IPCLs were observed in 94.4 % of cases in the NERD group and 38 % of cases in the control group ( P  < 0.05). There were significant differences in IPCL abnormalities between groups that were associated with histologically identified inflammation. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 94.4 %, 61.9 %, 80.9 %, 86.6 %, and 82.4 %, respectively. The 24-hour pH-impedance-monitoring test was used as the gold standard. The Kappa interobserver and intraobserver values were 0.85 and 0.90, respectively. Conclusion  The OE system with optical magnification can detect MMEL and predict NERD with high sensitivity, accuracy, and interobserver and intraobserver agreement. Presence of IPCLs highly correlates with histologically identified inflammation.

New classifications of gastroesophageal reflux disease: an improvement for patient management?

Introduction: Gastroesophageal reflux disease (GERD) is a very common and often debilitating disease. In the broad spectrum of GERD phenotypes, three main groups may be traditionally distinguished: 1) patients only affected by esophageal and/or extra-esophageal symptoms; 2) patients with erosive esophagitis and 3) patients with further complications. Areas covered: This review provides an overview on the current classifications of GERD patients, and their impact on their management. Expert opinion: In 2017, the GERD Consensus Working Group focused the attention on patients unresponsive to PPIs. In this scenario, a diagnosis of GERD might be confirmed by evident signs of erosive esophagitis and the finding of pH or multichannel intraluminal impedance-pH tests, such as more than 6%. The 'Lyon Consensus' panel of experts confirmed that positive indices of reflux-symptom association, without other altered parameters, represent reflux hypersensitivity. GERD requires a customized management; it is crucial to assess frequency and severity of symptoms and their response to an optimal course of therapy as well as to explore the endoscopic alterations and consider other diagnoses responsible for persistent symptoms.

Diagnostic efficacy of dual-focus endoscopy with narrow-band imaging using simplified dyad criteria for superficial esophageal squamous cell carcinoma

BACKGROUND

Our previous studies have shown the diagnostic utility of a newly developed dual-focus endoscope with narrow-band imaging (DF-NBI) and simplified dyad criteria for detection of superficial esophageal squamous cell carcinoma (SESCC). This clinical trial aimed to study the diagnostic efficacy of DF-NBI with dyad criteria for detecting SESCC compared to white light imaging (WLI).

METHODS

This was a single-arm prospective comparative trial. We enrolled 170 consecutive high-risk patients for esophageal squamous cell carcinoma. Patients were initially examined with WLI by one independent endoscopist and then the other performed DF-NBI blinded to the WLI diagnosis to avoid a carry-over effect. Lesions showing proliferation and/or various shapes of intrapapillary capillary loops (IPCL) under DF-NBI (i.e., dyad criteria) were endoscopically diagnosed as SESCC including high-grade intraepithelial neoplasia. The primary endpoint was sensitivity of WLI and DF-NBI for detecting SESCC. The secondary endpoints were the diagnostic performance (i.e., specificity and accuracy) and inter/intra-observer concordance of DF-NBI with dyad criteria.

RESULTS

A total 77 SESCCs were detected. The sensitivity of DF-NBI for SESCC was significantly higher than that of WLI (91% vs. 51%, P < 0.001). The specificity and accuracy of WLI and DF-NBI using dyad criteria were 100% vs. 84%, and 86% vs. 86%, respectively. Various shapes and proliferation of IPCL showed the highest value in inter-observer and intra-observer agreements (κ = 0.77 and 0.82, respectively).

CONCLUSION

DF-NBI combined with dyad criteria may be a promising technique with a high sensitivity for diagnosis of SESCC and high inter/intra-observer agreement.

Linked color imaging improves detection of minimal change esophagitis in non-erosive reflux esophagitis patients

Background and study aims  Non-erosive reflux disease (NERD) includes minimal change esophagitis (MCE) and no endoscopic abnormalities. However, for most endoscopists, it is difficult to detect MCE with conventional white-light endoscopy (WLE). Linked color imaging (LCI) technology is the most recently developed image-enhancing technology and improves detection and differentiation of subtle mucosal changes using a color contrast method. This study assessed the efficacy of WLE combined with LCI for diagnosing MCE compared with WLE. Patients and methods  Between February and May 2017, 44 NERD patients and 40 healthy subjects were enrolled in our study. First, the distal esophagus was examined using WLE followed by LCI. Second, three experienced endoscopists observed all the patients' white-light (WL) images and corresponding images of WL and LCI and then recorded presence or absence of minimal change esophagitis (MCE +/-). The proportion of minimal change between the two groups was then compared. Third, five blinded endoscopists with different levels of endoscopic experience assessed whether MCE was present. Intraobserver reproducibility and interobserver agreement were described using the kappa value. Results  The proportion of MCE in the NERD group (70.8 %, 35/48) was higher than that in the control group (22.5 %, 9/40, P  < 0.001) when diagnosed by the three experienced endoscopists. Detection rates for MCE using WLE combined with LCI were higher than those using WLE (43/88, 48.9 % vs. 29/88, 33.0 %, P  < 0.001). With WLE combined with LCI, intraobserver reproducibility significantly improved, indicating that the combined approach can improve interobserver agreement compared with using WLE alone. Conclusions  Endoscopic diagnosis of MCE using WLE combined with LCI images is effective. Intraobserver reproducibility and interobserver agreement in MCE can be improved when LCI is applied with conventional imaging (Clinical trial registration number: NCT03068572).

The added value of magnifying endoscopy in diagnosing patients with certain gastroesophageal reflux disease

PURPOSE

In most cases gastroesophageal reflux disease proceeds without macroscopic erosions in the esophagus. We aimed to clarify if abnormalities detectable in magnifying endoscopy may offer additional diagnostic criteria for gastroesophageal reflux disease and to what histopathologic structures do they correspond.

PATIENTS/METHODS

Esophageal mucosa above and below Z-line was evaluated under x115 magnification in 67 gastroesophageal reflux disease patients (11 with erosive reflux disease, 28 with Barrett's esophagus, 28 with nonerosive reflux disease) and in 12 patients without gastroesophageal reflux disease (negative control group). Features characteristic of gastroesophageal reflux disease were specified by comparing erosive reflux disease and Barrett's esophagus patients with negative control group. Afterwards the presence of identified features were evaluated in nonerosive reflux disease group. Interobserver agreement in the recognition of the proposed criteria was rated. Biopsies collected from the mucosa above Z-line were evaluated histologically after hematoxylin and eosin staining.

RESULTS

Endoscopic lesions characteristic of gastroesophageal reflux disease were: microerosions, abnormal intrapapillary capillary loops, obscured palisade vessels, white points, big triangular indentations of Z-line and villous mucosa below Z-line. The presence of two or more of the above features indicated gastroesophageal reflux disease with 97% sensitivity and 75% specificity. Substantial interobserver agreement was achieved in evaluation of obscured palisade vessels, abnormal intrapapillary capillary loops and white points. Endoscopic lesions were correlated to histology. Lesions identified with magnifying endoscopy were helpful in discerning between negative control group and nonerosive reflux disease patients.

CONCLUSIONS

Magnifying endoscopy reveals abnormalities that can be used as additional endoscopic diagnostic criteria of gastroesophageal reflux disease.

Image-enhanced endoscopy is specific for the diagnosis of non-erosive gastroesophageal reflux disease

OBJECTIVES

We assessed the performance characteristics of image-enhanced endoscopy with i-Scan or narrow band imaging (NBI) in patients with non-erosive gastroesophageal reflux disease (GERD) compared to controls without heartburn.

MATERIAL AND METHODS

Image-enhanced endoscopic findings of vascularity at the squamocolumnar junction, distal esophageal micro-erosions, and non-round pit pattern at the squamocolumnar junction were assessed in cases (heartburn not responsive to PPIs, positive results on validated GERD questionnaire, no esophageal erosions, esophageal biopsies with histologic evidence of GERD (basal cell hyperplasia, elongation of papillae and dilation of intercellular spaces all required)) and in controls (no GERD symptoms or esophageal erosions).

RESULTS

Twenty cases and 60 controls were compared. The pre-defined features were more common in cases vs.

CONTROLS

vascularity RR = 4.9 (95% CI: 2.4-10.0), specificity = 86.7%; micro-erosions RR = 9.7 (3.6-26.5), specificity = 93.3%; non-round pit pattern RR = 2.4 (1.7-3.3), specificity = 60.0%; combination of vascularity and micro-erosions RR = 30.0 (4.1-220), specificity = 98.3%. These differences were consistent with both i-Scan and NBI.

CONCLUSIONS

Image-enhanced endoscopic findings of vascularity and micro-erosions were very specific for non-erosive GERD. Image-enhanced endoscopy may be useful in real-time diagnosis of non-erosive GERD when patients undergo upper endoscopy for heartburn. The relative utility of image-enhanced endoscopy vs. pH-impedance monitoring, based on efficacy, cost and patient acceptance, requires additional study.

Recent Advances in the Pharmacological Management of Gastroesophageal Reflux Disease

The management of proton pump inhibitor-refractory GERD (rGERD) is a challenge in clinical practice. Since up to one-third of patients with typical GERD symptoms (heartburn and/or acid regurgitation) are not satisfied with proton pump inhibitor (PPI) therapy, new drug development targeting different pathophysiologies of GERD is imperative. At present, no other drugs serve as a more potent acid suppression agent than PPIs. As an add-on therapy, histamine type-2 receptor antagonists, alginates, prokinetics and transient lower esophageal sphincter relaxation inhibitors have some impact on the subgroups of rGERD, but greater effectiveness and fewer adverse effects for widespread use are required. Visceral hypersensitivity also contributes to the perception of GERD symptoms, and neuromodulators including antidepressants play a role in this category. Esophageal pH-impedance monitoring helps to distinguish functional heartburn from true GERD, and psychologic medication and cognitive behavior therapy are further therapy options instead of PPIs.

Emerging dilemmas in the diagnosis and management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is common, but less so than widely reported because of inconsistencies in definition. In clinical practice, the diagnosis is usually based on a symptom assessment without testing, and the extent of diagnostic testing pursued should be limited to that which guides management or which protects the patient from the risks of a potentially morbid treatment or an undetected early (or imminent) esophageal adenocarcinoma or which does both. When testing is pursued, upper gastrointestinal endoscopy is the most useful initial diagnostic test because it evaluates for the major potential morbidities (Barrett's, stricture, and cancer) associated with GERD and facilitates the identification of some alternative diagnostic possibilities such as eosinophilic esophagitis. However, endoscopy is insensitive for diagnosing GERD because most patients with GERD have non-erosive reflux disease, a persistent diagnostic dilemma. Although many studies have tried to objectify the diagnosis of GERD with improved technology, this is ultimately a pragmatic diagnosis based on response to proton pump inhibitor (PPI) therapy, and, in the end, response to PPI therapy becomes the major indication for continued PPI therapy. Conversely, in the absence of objective criteria for GERD and the absence of apparent clinical benefit, PPI therapy is not indicated and should be discontinued. PPIs are well tolerated and safe, but nothing is perfectly safe, and in the absence of measurable benefit, even a miniscule risk dominates the risk-benefit assessment.

Diagnosis and treatment of gastroesophageal reflux disease: recommendations of the Asociación Mexicana de Gastroenterología

Emerging concepts in the pathophysiology of gastroesophageal reflux disease (GERD) and the constant technologic advances in the diagnosis and treatment of this clinical condition make it necessary to frequently review and update the clinical guidelines, recommendations, and official statements from the leading academic groups worldwide. The Asociación Mexicana de Gastroenterología (AMG), aware of this responsibility, brought together national experts in this field to analyze the most recent scientific evidence and formulate a series of practical recommendations to guide and facilitate the diagnostic process and efficacious treatment of these patients. The document includes algorithms, figures, and tables for convenient consultation, along with opinions on GERD management in sensitive populations, such as pregnant women and older adults.

Adult and paediatric GERD: diagnosis, phenotypes and avoidance of excess treatments

Detailed investigations and objective measurements in patients with symptoms of gastro-oesophageal reflux should be performed with the intent of making the correct diagnosis, thus enabling choice of appropriate therapy. Establishing the most effective therapy is particularly important in adults who do not respond to standard treatment and in children. The use of PPIs for suspected GERD has increased substantially over the past decade, providing great relief in patients with acid-related symptoms, but also leading to adverse effects and a considerable economic burden. Adults with functional heartburn do not benefit from PPIs, while prolonged PPI use in patients with extraoesophageal symptoms remains a controversial area. Moreover, PPIs are not indicated in infants with GERD unless symptoms are proven to be acid-related. With regard to antireflux surgery, patients must be carefully selected to avoid the need for ongoing PPI treatment postoperatively. Correct diagnosis and phenotyping of patients with symptoms attributed to gastro-oesophageal reflux through detailed investigations is therefore imperative, leading to improved patient outcomes and rationalized use of available treatment options. In this Review, we outline currently available diagnostic tests and discuss approaches to limit any unnecessary medical or surgical interventions.

Asia-Pacific consensus on the management of gastro-oesophageal reflux disease: an update focusing on refractory reflux disease and Barrett's oesophagus

OBJECTIVE

Since the publication of the Asia-Pacific consensus on gastro-oesophageal reflux disease in 2008, there has been further scientific advancement in this field. This updated consensus focuses on proton pump inhibitor-refractory reflux disease and Barrett's oesophagus.

METHODS

A steering committee identified three areas to address: (1) burden of disease and diagnosis of reflux disease; (2) proton pump inhibitor-refractory reflux disease; (3) Barrett's oesophagus. Three working groups formulated draft statements with supporting evidence. Discussions were done via email before a final face-to-face discussion. We used a Delphi consensus process, with a 70% agreement threshold, using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria to categorise the quality of evidence and strength of recommendations.

RESULTS

A total of 32 statements were proposed and 31 were accepted by consensus. A rise in the prevalence rates of gastro-oesophageal reflux disease in Asia was noted, with the majority being non-erosive reflux disease. Overweight and obesity contributed to the rise. Proton pump inhibitor-refractory reflux disease was recognised to be common. A distinction was made between refractory symptoms and refractory reflux disease, with clarification of the roles of endoscopy and functional testing summarised in two algorithms. The definition of Barrett's oesophagus was revised such that a minimum length of 1 cm was required and the presence of intestinal metaplasia no longer necessary. We recommended the use of standardised endoscopic reporting and advocated endoscopic therapy for confirmed dysplasia and early cancer.

CONCLUSIONS

These guidelines standardise the management of patients with refractory gastro-oesophageal reflux disease and Barrett's oesophagus in the Asia-Pacific region.

i-Scan detection of minimal change esophagitis in dyspeptic patients with or without Gastroesophageal Reflux disease

Background

The association of minimal change esophagitis (MCE) with GERD is controversial. i-Scan endoscopy (SE) provides high resolution and modulation of images that may improve minimal change lesion (MCL) detection. We aimed to assess the efficacy of SE in detecting MCL in dyspeptic patients with GERD compared with patients without GERD by GerdQ or by endoscopy with 24-h pH monitoring (PHM) and in normal volunteers.

Methods

This is a cohort study conducted at a tertiary center. All dyspeptic patients were prospectively recruited. All patients completed a validated Thai version of GerdQ and then underwent endoscopy. Forty normal volunteers as a control group were recruited for endoscopy. The distal esophagus was examined by high definition endoscopy and SE sequentially. All had PHM done. GERD was diagnosed by Los Angeles classification A-D and/or by a positive PHM. MCE was diagnosed when MCL or combination of MCL was present.

Results

Of 174 patients, 144 completed the study protocol. After the exclusion of 6 patients, 138 remained for analysis. Overlapping GERD symptoms were found in 44.2 % and 26.8 % had confirmed GERD. Group A was comprised of 61 patients with a positive GerdQ and 77 patients in group B had a negative GerdQ. Twenty-four in group A, 28 in group B and 7 in the control group had MCE that was not significantly different. MCE in GERD was significantly higher (51.45 %) than in non-GERD (32.7 %) (p = 0.047) and in the control group (20.58 %) (p = 0.007). The sensitivity, specificity, positive predictive value, and negative predictive value of SE were 51.35 %, 67.33 %, 36.54 % and 79.06 %, respectively.

Conclusion

In dyspeptic patients, SE detected more MCE in GERD than in non-GERD patients and in the control group.

Trial registration

ClinicalTrials.gov number NCT01742377

Identifying Minimal Changes in Nonerosive Reflux Disease: Is the Pay Worth the Labor?

Gastroesophageal reflux disease has a variable presentation on upper endoscopy. Gastroesophageal reflux disease can be divided into 3 endoscopic categories: Barrett's esophagus, erosive esophagitis, and normal mucosa/nonerosive reflux disease (NERD). Each of these phenotypes behave in a distinct manner, in regards to symptom response to treatment, and risk of development of complications such as esophageal adenocarcinoma. Recently, it has been proposed to further differentiate NERD into 2 categories: those with and those without "minimal changes." These minimal changes include endoscopic abnormalities, such as villous mucosal surface, mucosal islands, microerosions, and increased vascularity at the squamocolumnar junction. Although some studies have shown that patients with minimal changes may have higher rates of esophageal acid exposure compared with those without minimal changes, it is currently unclear if these patients behave differently than those currently categorized as having NERD. The clinical utility of identifying these lesions should be weighed against the cost of the requisite equipment and the additional time required for diagnosis, compared with conventional white light endoscopy.

Electronic chromoendoscopy

Electronic chromoendoscopy technologies provide image enhancement and may improve the diagnosis of mucosal lesions. Although strides have been made in standardization of image characterization, especially with NBI, further image-to-pathology correlation and validation are required. There is promise for the development of a resect and discard policy for diminutive adenomas by using electronic chromoendoscopy; however, before this can be adopted, further community-based studies are needed. Further validated training tools for NBI, FICE, and i-SCAN will also be required for the use of these techniques to become widespread.

Refractory gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a condition that develops when the reflux of stomach contents into the esophagus causes troublesome symptoms, esophageal injury, and/or complications. Use of proton pump inhibitors (PPI) remains the standard therapy for GERD and is effective in most patients. Those whose symptoms are refractory to PPIs should be evaluated further and other treatment options should be considered, according to individual patient characteristics. Response to PPIs could be total (no symptoms), partial (residual breakthrough symptoms), or absent (no change in symptoms). Patients experiencing complete response do not usually need further management. Patients with partial response can be treated surgically or by using emerging endoscopic therapies. Patients who exhibit no response to PPI need further evaluation to rule out other causes.

Narrow-Band Imaging of Laryngeal Images and Endoscopically Proven Reflux Esophagitis

Objective

To compare the difference between white light (WL) and narrow-band imaging (NBI) endoscopy in evaluating patients who had reflux laryngitis and esophagitis.

Study Design

Retrospective review of medical records and endoscopic images.

Setting

Outpatient clinic.

Subjects and Methods

There were 102 consecutive patients with reflux esophagitis (mean age, 48 ± 11 years) who had office-based transnasal esophagoscopy (TNE) with WL and NBI views, including 60 men (59%) and 42 women (41%). We compared WL and NBI endoscopy in observing the laryngeal and esophageal epithelium. The nasopharynx, base of the tongue, epiglottis, hypopharynx, larynx, esophagus, gastroesophageal junction, and stomach were examined, and all procedures were digitally recorded. All patients were evaluated with WL and NBI views to determine the reflux finding score (RFS) in the larynx and Los Angeles (LA) classification grade in the esophagus.

Results

The NBI views were more sensitive than the WL views in the erythema/hyperemia, vocal cord edema, and global RFS scores. The NBI view facilitated the identification of the erythema/hyperemia change representing dilation or proliferation of microvessels caused by epithelial inflammation. The global RFS score was significantly associated with severity of LA grade only with the NBI view.

Conclusion

The endoscopic findings with the NBI view permit an easier identification of the RFS parameters of laryngeal erythema/vocal cord edema, which have a stronger correlation with the severity of reflux esophagitis, than the WL view. The importance of NBI in the evaluation of reflux laryngitis and gastroesophageal reflux disease deserves further study.

Correlation of narrow band imaging endoscopy and histopathology in the diagnosis of nonerosive reflux disease

Background /Aim: Narrow band imaging (NBI) is a novel, innovative high-resolution endoscopic technique, which utilizes spectral narrow band filter for the visualization of mucosal patterns and microvasculature. Nonerosive reflux disease (NERD) is a type of gastroesophageal reflux disease (GERD) and it is characterized by reflux symptoms without mucosal breaks on white light endoscopy (WLE). Biopsies from distal esophagus of GERD patients show group of histologic features such as basal cell hyperplasia, elongation of lamina propria papillae, and inflammatory cells. The present study was undertaken to evaluate diagnostic utility of NBI endoscopy and biopsy study in NERD patients and also to correlate NBI endoscopy findings with histologic features of GERD.

PATIENTS AND METHODS

A total of 71 cases of NERD having symptom score more than 10 and those not having erosion on WLE were recruited prospectively and underwent NBI endoscopic examination. Two mucosal biopsies were taken at 3 cm above the squamocolumnar junction.

RESULTS

Histologic features of GERD were seen in 50 (70.4%) out of 71 cases. No significant correlation between NBI endoscopic findings with histologic features of GERD was found.

CONCLUSION

The present study showed that histopathologic evaluation of distal esophageal mucosa has promising diagnostic value over NBI endoscopy in NERD patients. Use of newly introduced NBI technique requires tremendous familiarity for the detection of the cases of NERD, which show histologic features of GERD.

High-definition endoscopy with iScan and Lugol's solution for the detection of inflammation in patients with nonerosive reflux disease: histologic evaluation in comparison with a control group

Nonerosive reflux disease (NERD) is commonly diagnosed in patients with symptoms of reflux. The aim of the present study was to determine whether high-definition endoscopy (HD) plus equipped with the iScan function or chromoendoscopy with Lugol's solution might permit the differentiation of NERD patients from those without reflux symptoms, proven by targeted biopsies of endoscopic lesions. A total of 100 patients without regular intake of proton pump inhibitors and with a normal conventional upper endoscopy were prospectively divided into NERD patients and controls. A second upper endoscopy was performed using HD+ with additional iScan function and then Lugol's solution was applied. Biopsy specimens were taken from the gastroesophageal junction in all patients. A total of 65 patients with reflux symptoms and 27 controls were included. HD(+) endoscopy with iScan revealed subtle mucosal breaks in 52 patients; the subsequent biopsies confirmed esophagitis in all cases. After Lugol's solution, 58 patients showed mucosal breaks. Sensitivity for the iScan procedure was 82.5%, whereas that for Lugol's solution was 92.06%. Excellent positive predictive values of 100% and 98.3%, respectively, were noted. The present study suggests that the majority of patients with NERD and typical symptoms of reflux disease can be identified by iScan or Lugol's chromoendoscopy as minimal erosive reflux disease (ERD) patients.

MicroRNA Expression can be a Promising Strategy for the Detection of Barrett's Esophagus: A Pilot Study

Objectives:

Patient outcomes for esophageal adenocarcinoma (EAC) have not improved despite huge advances in endoscopic therapy because cancers are being diagnosed late. Barrett's esophagus (BE) is the primary precursor lesion for EAC, and thus the non-endoscopic molecular diagnosis of BE can be an important approach to improve EAC outcomes if robust biomarkers for timely diagnosis are identified. MicroRNAs (miRNAs) are tissue-specific novel biomarkers that regulate gene expression and may satisfy this requirement.

Methods:

Patients with gastroesophageal reflux disease (GERD) and BE were selected from an ongoing tissue and serum repository. BE was defined by the presence of intestinal metaplasia. Previously published miRNA sequencing profiles of GERD and BE patients allowed us to select three miRNAs, miR-192-5p, -215-5p, and -194-5p, for further testing in a discovery cohort and an independent validation cohort. Receiver operating curves were generated to calculate the diagnostic accuracy of these miRNAs for BE diagnosis. To test specificity, the miRNA signature was compared with those of the gastric cardia epithelium and the non-intestinal-type columnar epithelium (another definition of BE). In addition, to gain insights into BE origin (intestinal vs non-intestinal), global BE miRNA profiles were compared with the published miRNA profiles of other columnar epithelia in the gastrointestinal tract, that is, normal stomach and small and large intestine.

Results:

The discovery cohort included 67 white male patients (40 with GERD and 27 with BE). The validation cohort included 28 patients (19 with GERD and 11 with BE). In the discovery cohort, the sensitivity, specificity and area under the curve (AUC) of the three mRNAs for BE diagnosis were 92–100%, 94–95%, and 0.96–0.97, respectively. During validation, the sensitivity and specificity of miRNAs for BE diagnosis were as follows: miR-192-5p, 92% and 94%, AUC 0.94 (0.80–0.99, P=0.0004); miR-215-5p, 100% and 94%, AUC 0.98 (0.84–1, P=0.0004); and miR-194-5p, 91% and 94%, AUC 0.96 (0.80–0.99, P=0.0001), respectively. The tested miRNAs identified all BE patients in both the discovery and the validation cohorts. When compared with non intestinal-type columnar and gastric cardia epithelia, the miRNA signature was specific to the intestinal-type columnar epithelium. Comparisons of BE miRNA sequencing data to published data sets for the normal stomach, small intestine and large intestine confirmed that two of the three miRNAs (miR-215-5p and -194-5p) were specific to the intestinal-type epithelium.

Conclusions:

MicroRNAs are highly accurate for detecting intestinal-type BE epithelia and should be tested further for the non-endoscopic molecular diagnosis of BE.

High definition plus colonoscopy combined with i-scan tone enhancement vs. high definition colonoscopy for colorectal neoplasia: A randomized trial

BACKGROUND

High definition endoscopy is the accepted standard in colonoscopy. However, an important problem is missed polyps.

AIMS

Our objective was to assess the additional adenoma detection rate between high definition colonoscopy with tone enhancement (digital chromoendoscopy) vs. white light high definition colonoscopy.

METHODS

In this prospective randomized trial patients were included to undergo a tandem colonoscopy. The first exam was a white light colonoscopy with removal of all visualized polyps. The second examination was randomly assigned in a 1:1 ratio as either again white light colonoscopy (Group A) or colonoscopy with tone enhancement (Group B). Primary endpoint was the adenoma detection rate during the second withdrawal (sample size calculation - 40 per group).

RESULTS

67 lesions (Group A: n=34 vs. Group B: n=33) in 80 patients (mean age 61 years, male 64%) were identified on the first colonoscopy. The second colonoscopy detected 78 additional lesions: n=60 with tone enhancement vs. n=18 with white light endoscopy (p<0.001). Tone enhancement found more additional adenomas (A n=20 vs. B n=6, p=0.006) and identified significantly more missed adenomas per subject (0.5 vs. 0.15, p=0.006).

CONCLUSIONS

High definition plus colonoscopy with tone enhancement detected more adenomas missed by white light colonoscopy.

Wireless ambulatory esophageal pH monitoring in dogs with clinical signs interpreted as gastroesophageal reflux

Background

Although gastroesophageal reflux (GER) often is assumed to be causative for upper gastrointestinal and respiratory signs in dogs, no attempts have been made to verify this assumption.

Objectives

To monitor esophageal pH with the Bravo pH system in healthy dogs and client‐owned dogs displaying signs commonly attributed to GER.

Animals

Seven healthy and 22 client‐owned dogs.

Methods

After routine esophagogastroduodenoscopy, radiotelemetric pH capsules were placed in distal esophagus for continuous pH recording. Reflux was defined as single pH measurement <4. At discharge, owners were instructed to press individually predefined clinical sign‐buttons on the receiver whenever indicated. Results between groups were compared using Mann–Whitney U‐test.

Results

The median (range) number of refluxes in client‐owned and healthy dogs, respectively, was 17 (1–205) and 10 (1–65), the number of refluxes >5 minutes in duration was 1 (0–14), and 1 (0–4), duration of longest reflux (min) was 10 (0–65) and 8 (0–27), and fractional time pH <4 (%) was 0.76% (0.01–6.28), and 0.3% (0–3.1). No differences were found between groups. The median of 7 (1–35) clinical sign‐button pushes were recorded in 21 dogs. Median of 12.5% (2.8% [1/35]–50% [2/4]) reflux‐positive clinical sign‐button pushes was found in 10 dogs with reflux‐positive pushes. Five (22.7%) dogs had increased esophageal acid exposure, and mild esophagitis was noted in 1 dog.

Conclusion and Clinical Importance

Despite evidence of increased GER in some dogs, the clinical sign‐reflux association remained poor. Future investigation should focus on dogs with esophagitis.

Vascular contrast in narrow-band and white light imaging

Narrow-band imaging (NBI) is a spectrally selective reflectance imaging technique that is used clinically for enhancing visualization of superficial vasculature and has shown promise for applications such as early endoscopic detection of gastrointestinal neoplasia. We have studied the effect of vessel geometry and illumination wavelength on vascular contrast using idealized geometries in order to more quantitatively understand NBI and broadband or white light imaging of mucosal tissue. Simulations were performed using a three-dimensional, voxel-based Monte Carlo model incorporating discrete vessels. In all cases, either 415 or 540 nm illumination produced higher contrast than white light, yet white light did not always produce the lowest contrast. White light produced the lowest contrast for small vessels and intermediate contrast for large vessels (diameter≥100  μm) at deep regions (vessel depth≥200  μm). The results show that 415 nm illuminations provided superior contrast for smaller vessels at shallow depths while 540 nm provided superior contrast for larger vessels in deep regions. Besides 540 nm, our studies also indicate the potential of other wavelengths to achieve high contrast of large vessels at deep regions. Simulation results indicate the importance of three key mechanisms in determining spectral variations in contrast: intravascular hemoglobin (Hb) absorption in the vessel of interest, diffuse Hb absorption from collateral vasculature, and bulk tissue scattering. Measurements of NBI contrast in turbid phantoms incorporating 0.1-mm-diameter hemoglobin-filled capillary tubes indicated good agreement with modeling results. These results provide quantitative insights into light-tissue interactions and the effect of device and tissue properties on NBI performance.

Association of esophageal inflammation, obesity and gastroesophageal reflux disease: from FDG PET/CT perspective

OBJECTIVE

Gastroesophageal reflux disease (GERD) is associated with bothersome symptoms and neoplastic progression into Barrett's esophagus and esophageal adenocarcinoma. We aim to determine the correlation between GERD, esophageal inflammation and obesity with 18F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT).

METHODS

We studied 458 subjects who underwent a comprehensive health check-up, which included an upper gastrointestinal endoscopy, FDG PET/CT and complete anthropometric measures. GERD symptoms were evaluated with Reflux Disease Questionnaire. Endoscopically erosive esophagitis was scored using the Los Angeles classification system. Inflammatory activity, represented by standardized uptake values (SUVmax) of FDG at pre-determined locations of esophagus, stomach and duodenum, were compared. Association between erosive esophagitis, FDG activity and anthropometric evaluation, including body mass index (BMI), waist circumference, visceral and subcutaneous adipose tissue volumes were analyzed.

RESULTS

Subjects with erosive esophagitis (n = 178, 38.9%) had significantly higher SUVmax at middle esophagus (2.69±0.74 vs. 2.41±0.57, P<.001) and esophagogastric junction (3.10±0.89 vs. 2.38±0.57, P<.001), marginally higher at upper esophageal sphincter (2.29±0.42 vs. 2.21±0.48, P = .062), but not in stomach or duodenum. The severity of erosive esophagitis correlated with SUVmax and subjects with Barrett's esophagus had the highest SUVmax at middle esophagus and esophagogastric junction. Heartburn positively correlated with higher SUVmax at middle oesophagus (r = .262, P = .003). Using multivariate regression analyses, age (P = .027), total cholesterol level (P = .003), alcohol drinking (P = .03), subcutaneous adipose tissue (P<.001), BMI (P<.001) and waist circumference (P<.001) were independently associated with higher SUVmax at respective esophageal locations.

CONCLUSIONS

Esophageal inflammation demonstrated by FDG PET/CT correlates with endoscopic findings and symptomatology of GERD. Obesity markers, both visceral and general, are independent determinants of esophageal inflammation.

Update on narrow band imaging in disorders of the upper gastrointestinal tract

With the ever-increasing concern regarding morbidity and mortality associated with diseases of the gastrointestinal tract, the importance of an effective and efficient diagnostic tool cannot be overstated. The standard of care currently is an examination using conventional white light endoscopy. This approach may occasionally overlook areas exhibiting a premalignant change. Numerous image-enhanced modalities have been recently introduced. Narrow band imaging (NBI) appears to be the most prominent of these and perhaps the most commonly used. Thepresent review will focus on some of the newer studies on NBI and its utility in the diagnosis of malignant, pre-malignant and chronic inflammatory conditions of the upper gastrointestinal tract.

High definition endoscopy and "narrow band imaging" in the diagnosis of gastroesophageal reflux disease

INTRODUCTION

The gastroesophageal reflux disease is a common condition in the western world but less than half of patients present endoscopic abnormalities, making a standard procedure unsuitable for diagnosis. High definition endoscopy coupled with narrow band imaging has shown potential for differentiation of lesions and possible biopsy, allowing early diagnosis and treatment.

METHODS

This review describes the principles of biotic and their influence in obtaining images with better definition of the vessels in the mucosa, through the narrow band imaging. Selected papers using it in patients with reflux disease and Barrett's esophagus are analyzed in several ways, highlighting the findings and limitations.

CONCLUSION

The meaning of the narrow band imaging in the endoscopic diagnosis of reflux disease will be defined by large scale studies, with different categories of patients, including assessment of symptoms and response to treatment.

Investigation of relationships among gastroesophageal reflux disease subtypes using narrow band imaging magnifying endoscopy

AIM: To investigate the relationships among subtypes of gastroesophageal reflux disease (GERD) using narrow band imaging (NBI) magnifying endoscopy.

METHODS: A reflux disease questionnaire was used to screen 120 patients representing the three subtypes of GERD (n = 40 for each subtypes): nonerosive reflux disease (NERD), reflux esophagitis (RE) and Barrett’s esophagus (BE). NBI magnifying endoscopic procedure was performed on the patients as well as on 40 healthy controls. The demographic and clinical characteristics, and NBI magnifying endoscopic features, were recorded and compared among the groups. Targeted biopsy and histopathological examination were conducted if there were any abnormalities. SPSS 18.0 software was used for all statistical analysis.

RESULTS: Compared with healthy controls, a significantly higher proportion of GERD patients had increased number of intrapapillary capillary loops (IPCLs) (78.3% vs 20%, P < 0.05), presence of microerosions (41.7% vs 0%, P < 0.05), and a non-round pit pattern below the squamocolumnar junction (88.3% vs 30%, P < 0.05). The maximum (228 ± 4.8 vs 144 ± 4.7, P < 0.05), minimum (171 ± 3.8 vs 103 ± 4.4, P < 0.05), and average (199 ± 3.9 vs 119 ± 3.9, P < 0.05) numbers of IPCLs/field were also significantly greater in GERD patients. However, comparison among groups of the three subtypes showed no significant differences or any linear trend, except that microerosions were present in 60% of the RE patients, but in only 35% and 30% of the NERD and BE patients, respectively (P < 0.05).

CONCLUSION: Patients with GERD, irrespective of subtype, have similar micro changes in the distal esophagus. The three forms of the disease are probably independent of each other.