Patients With Esophageal Adenocarcinoma With Prior Gastroesophageal Reflux Disease Symptoms Are Similar to Those Without Gastroesophageal Reflux Disease: A Cross-Sectional Study

INTRODUCTION

A substantial proportion of patients with esophageal adenocarcinoma (EAC) do not report gastroesophageal reflux disease (GERD) symptoms. This study aimed to compare the risk factor profiles and cancer stage at presentation of patients with EAC with and without prior GERD.

METHODS

In this retrospective cross-sectional study, patients with EAC were divided into 2 cohorts: (i) EAC with prior GERD: patients who reported typical GERD symptoms (heartburn or regurgitation) ≥1 year before cancer diagnosis and (ii) EAC without prior GERD: patients who did not report prior GERD symptoms or reported symptoms within 1 year of their cancer diagnosis. Baseline demographics, risk factors, and cancer stage at presentation were compared between the 2 cohorts. In addition, the distribution of patients based on numbers of BE/EAC-associated risk factors (1, 2, 3, 4, and 5 or more) was examined in the symptomatic and asymptomatic cohorts.

RESULTS

Over 13 years, 388 patients with EAC with prior GERD and 245 patients with EAC without prior GERD were recruited. Both groups had similar baseline demographics and risk factors, but patients with EAC with prior GERD were more likely to have a history of BE. Asymptomatic patients had more advanced disease. Patients with 3 or more BE/EAC-related risk factors formed the largest proportion of patients in both the symptomatic and asymptomatic cohorts.

DISCUSSION

Patients with EAC with and without prior GERD symptoms are phenotypically similar, suggesting that BE screening efforts to prevent or detect early EAC should not be restricted to just those with GERD.

MULTICENTER, PROSPECTIVE TRIAL OF NON-ENDOSCOPIC BIOMARKER-DRIVEN DETECTION OF BARRETT'S ESOPHAGUS AND ESOPHAGEAL ADENOCARCINOMA

BACKGROUND

Preliminary data suggest that an encapsulated balloon (EsoCheckTM), coupled with a two methylated DNA biomarker panel (EsoGuardTM), detects Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) with high accuracy. The initial assay required sample freezing upon collection.

AIM

Assess a next-generation EsoCheck sampling device and EsoGuard assay in a much-enlarged multicenter study clinically enhanced by utilizing a CLIA-compliant assay and samples maintained at room temperature.

METHODS

Cases with nondysplastic BE (NDBE), dysplastic BE (indefinite=IND, low grade dysplasia = LGD, high grade dysplasia = HGD), EAC, junctional adenocarcinoma (JAC), plus endoscopy controls without esophageal intestinal metaplasia, were prospectively enrolled. Medical assistants at six institutions delivered the encapsulated balloon per orally, with inflation in the stomach. The inflated balloon sampled the distal 5 cm of the esophagus, then was deflated and retracted into the capsule, preventing sample contamination. EsoGuard bisulfite sequencing assayed levels of methylated Vimentin (mVIM) and methylated Cyclin A1 (mCCNA1).

RESULTS

A total of 243 evaluable patients - 88 cases (median age 68, 78% men, 92% white) and 155 controls (median age 57, 41% men, 88% white) - underwent adequate EsoCheck sampling. Mean procedural time was approximately 3 minutes. Cases included 31 NDBE, 16 IND/LGD, 23 HGD, and 18 EAC/JAC. Thirty-seven (53%) non-dysplastic and dysplastic BE cases were short segment BE (SSBE; < 3 cm). Overall sensitivity was 85% (95% CI= 0.78-0.93), and specificity was 85% (95% CI=0.79-0.90). Sensitivity for NDBE was 84%. EsoCheck/EsoGuard detected 100% of cancers (n=18).

CONCLUSION

EsoCheck/EsoGuard demonstrated high sensitivity and specificity in detecting BE and BE-related neoplasia.

The Bethesda ERCP Skills Assessment Tool (BESAT) can reliably differentiate endoscopists of different experience levels

Background and study aims The Bethesda ERCP Skill Assessment Tool (BESAT) is a video-based assessment tool of technical endoscopic retrograde cholangiopancreatography (ERCP) skill with previously established validity evidence. We aimed to assess the discriminative validity of the BESAT in differentiating ERCP skill levels. Methods Twelve experienced ERCP practitioners from tertiary academic centers were asked to blindly rate 43 ERCP videos using the BESAT. ERCP videos consisted of native biliary cannulation and sphincterotomy and were recorded from 10 unique endoscopists of various ERCP experience (from advanced endoscopy fellow to > 10 years of ERCP experience). Inter-rater reliability, discriminative validity, and internal structure validity were subsequently assessed. Results The BESAT was found to reliably differentiate between endoscopists of varying levels of ERCP experience with experienced ERCPists scoring higher than novice ERCPists in 11 of 13 (85%) instrument items. Inter-rater reliability for BESAT items ranged from good to excellent (intraclass correlation range: 0.86 to 0.93). Internal structure validity was assessed with item-total correlations ranging from 0.53 to 0.83. Conclusions Study findings demonstrate that the BESAT, a video-based ERCP skill assessment tool, has high inter-rater reliability and has discriminative validity in differentiating novice from expert ERCP skill. Further investigations are needed to determine the role of video-based assessment in improving trainee learning curves and patient outcomes.

EUS-guided coil injection therapy in the management of gastric varices: the first U.S. multicenter experience (with video)

BACKGROUND AND AIMS

Despite the significant morbidity associated with gastric variceal bleeding, there is a paucity of high-quality data regarding optimal management. EUS-guided coil injection therapy (EUS-COIL) has recently emerged as a promising endoscopic modality for the treatment of gastric varices (GV), particularly compared with traditional direct endoscopic glue injection. Although there are data on the feasibility and safety of EUS-COIL in the management of GV, these have been limited to select centers with particular expertise. The aim of this study was to report the first U.S. multicenter experience of EUS-COIL for the management of GV.

METHODS

This retrospective analysis included patients with bleeding GV or GV at risk of bleeding who underwent EUS-COIL at 10 U.S. tertiary care centers between 2018 and 2022. Baseline patient and procedure-related information was obtained. EUS-COIL entailed the injection of .018 inch or .035 inch hemostatic coils using a 22-gauge or 19-gauge FNA needle. Primary outcomes were technical success (defined as successful deployment of coil into varix under EUS guidance with diminution of Doppler flow), clinical success (defined as cessation of bleeding if present and/or absence of bleeding at 30 days' postintervention), and intraprocedural and postprocedural adverse events.

RESULTS

A total of 106 patients were included (mean age 60.4 ± 12.8 years; 41.5% female). The most common etiology of GV was cirrhosis (71.7%), with alcohol being the most common cause (43.4%). Overall, 71.7% presented with acute GV bleeding requiring intensive care unit stay and/or blood transfusion. The most common GV encountered were isolated GV type 1 (60.4%). A mean of 3.8 ± 3 coils were injected with a total mean length of 44.7 ± 46.1 cm. Adjunctive glue or absorbable gelatin sponge was injected in 82% of patients. Technical success and clinical success were 100% and 88.7%, respectively. Intraprocedural adverse events (pulmonary embolism and GV bleeding from FNA needle access) occurred in 2 patients (1.8%), and postprocedural adverse events occurred in 5 (4.7%), of which 3 were mild. Recurrent bleeding was observed in 15 patients (14.1%) at a mean of 32 days. Eighty percent of patients with recurrent bleeding were successfully re-treated with repeat EUS-COIL. No significant differences were observed in outcomes between high-volume (>15 cases) and low-volume (<7 cases) centers.

CONCLUSIONS

This U.S. multicenter experience on EUS-COIL for GV confirms high technical and clinical success with low adverse events. No significant differences were seen between high- and low-volume centers. Repeat EUS-COIL seems to be an effective rescue option for patients with recurrent bleeding GV. Further prospective studies should compare this modality versus other interventions commonly used for GV.

NON-ENDOSCOPIC ESOPHAGEAL SAMPLING DEVICE AND BIOMARKER PANEL FOR DETECTION OF BARRETT'S ESOPHAGUS (BE) AND ESOPHAGEAL ADENOCARCINOMA (EAC)

BACKGROUND

We previously reported an encapsulated balloon (EsoCheck TM , EC), which selectively samples the distal esophagus, that coupled with a two methylated DNA biomarker panel (EsoGuard TM , EG), detected Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC), with a sensitivity and specificity of 90.3% and 91.7%, respectively. This previous study utilized frozen EC samples.

AIM

To assess a next generation EC sampling device and EG assay that utilizes a room temperature sample preservative to enable office-based testing.

METHODS

Cases with nondysplastic (ND) and dysplastic (indefinite=IND, low grade dysplasia = LGD, high grade dysplasia = HGD) BE, EAC, junctional adenocarcinoma (JAC) and controls with no intestinal metaplasia (IM) were included. Nurses or physician assistants at six institutions, who were trained in EC administration, delivered the encapsulated balloon per orally and inflated it in the stomach. The inflated balloon was pulled back to sample 5 cm of the distal esophagus, then deflated and retracted into the EC capsule to prevent sample contamination from proximal esophagus. Nextgen EG sequencing assays performed on bisulfite-treated DNA extracted from EC samples determined levels of methylated Vimentin (mVIM) and methylated Cyclin A1 (mCCNA1) in a CLIA-certified laboratory, blinded to patients' phenotypes.

RESULTS

A total of 243 evaluable patients - 88 cases (median age 68 years, 78% men, 92% white) and 155 controls (median age 57 years, 41% men, 88% white) - underwent adequate EC sampling. Mean time for EC sampling was just over 3 minutes. The cases included 31 NDBE, 16 IND/LGD, 23 HGD, and 18 EAC/JAC. Thirty-seven (53%) of the non-dysplastic and dysplastic BE cases were short-segment BE (SSBE; < 3 cm). Overall sensitivity for detecting all cases was 85% (95% CI= 0.78-0.93) and specificity was 85% (95% CI=0.79-0.90). Sensitivity for NDBE was 84% (n=37). The EC/EG test detected 100% of cancers.

CONCLUSION

The next-generation EC/EG technology has been both successfully updated to incorporate a room temperature sample collection preservative and successfully implemented in a CLIA certified laboratory. When performed by trained personnel, EC/EG detects non-dysplastic BE, dysplastic BE, and cancer with high sensitivity and specificity, replicating the operating characteristics of the initial pilot study of this technology. Future applications utilizing EC/EG to screen broader populations at risk for developing cancer are proposed.

SIGNIFICANCE

This multi-center study demonstrates the successful performance of a commercially available clinically implementable non-endoscopic screening test for BE in the U.S., as recommended in the most recent ACG Guideline and AGA Clinical Update. It transitions and validates a prior academic laboratory-based study of frozen research samples over to a CLIA laboratory, one that also integrates a clinically practical room temperature method for sample acquisition and storage, enabling office-based screening.

Evidence-Based Cognitive Endoscopy Simulators: Do They Exist? A Systematic Search and Evaluation of Existing Platforms

BACKGROUND

The development of guidelines by gastroenterology societies increasingly stresses evidence-based endoscopic practice.

AIMS

We performed a systematic assessment to determine whether endoscopic video teaching platforms incorporate evidence-based educational strategies and methods in order to disseminate guideline-based endoscopic management strategies.

METHODS

Platforms with a video component were systematically identified using the Google search engine, Apple and Android application stores, and searching four major gastroenterology society websites and three known platforms, to identify all relevant platforms. Two video samples from each teaching platform were reviewed independently by two authors and assessed for use of a priori defined principles of evidence-based medicine, as determined by consensus agreement and for the use of simulation.

RESULTS

Fourteen platforms were included in the final analysis, and two videos from each were analyzed. One of the 14 platforms used simulation and incorporated evidence-based medicine principles consistently. Nine of the 14 platforms were not transparent in regard to citation. None of the platforms consistently cited the certainty of evidence or explained how evidence was selected.

CONCLUSIONS

Education of guideline-based endoscopic management strategies using principles of evidence-based medicine is under-utilized in endoscopic videos. In addition, the use of cognitive simulation is absent in this arena. There is a paucity of evidence-based cognitive endoscopy simulators designed for fellows that incorporate systematic evaluation, and efforts should be made to create this platform.

Impact of withdrawal time on adenoma detection rate: results from a prospective multicenter trial

BACKGROUND AND AIMS

Performing a high-quality colonoscopy is critical for optimizing the adenoma detection rate (ADR). Colonoscopy withdrawal time (a surrogate measure) of ≥6 minutes is recommended; however, a threshold of a high-quality withdrawal and its impact on ADR are not known.

METHODS

We examined withdrawal time (excluding polyp resection and bowel cleaning time) of subjects undergoing screening and/or surveillance colonoscopy in a prospective, multicenter, randomized controlled trial. We examined the relationship of withdrawal time in 1-minute increments on ADR and reported odds ratio (OR) with 95% confidence intervals. Linear regression analysis was performed to assess the maximal inspection time threshold that impacts the ADR.

RESULTS

A total of 1142 subjects (age, 62.3 ± 8.9 years; 80.5% men) underwent screening (45.9%) or surveillance (53.6%) colonoscopy. The screening group had a median withdrawal time of 9.0 minutes (interquartile range [IQR], 3.3) with an ADR of 49.6%, whereas the surveillance group had a median withdrawal time of 9.3 minutes (IQR, 4.3) with an ADR of 63.9%. ADR correspondingly increased for a withdrawal time of 6 minutes to 13 minutes, beyond which ADR did not increase (50.4% vs 76.6%, P < .01). For every 1-minute increase in withdrawal time, there was 6% higher odds of detecting an additional subject with an adenoma (OR, 1.06; 95% confidence interval, 1.02-1.10; P = .004).

CONCLUSIONS

Results from this multicenter, randomized controlled trial underscore the importance of a high-quality examination and efforts required to achieve this with an incremental yield in ADR based on withdrawal time. (Clinical trial registration number: NCT03952611.).

Meet EBE: The Development of an Evidence-Based Endoscopy Simulator

BACKGROUND AND AIMS

In the digital era of evidence-based medicine, there is a paucity of video endoscopy teaching platforms that use evidence-based medicine principles, or that allow for cognitive simulation of endoscopic management strategies. We created a guideline-based teaching platform for fellows that incorporates these features, and tested it.

METHODS

A pilot video module with embedded questions was drafted, and after incorporation of feedback from several attending gastroenterologists, an additional 2 modules were created. The embedded questions were designed to simulate cognitive management decisions as if the viewer were doing the endoscopy procedure in the video. A narrator explained the evidence behind the task being performed, and its certainty based on endoscopic guidelines. Quizzes and surveys were developed and administered to a sample of attendings and fellows who completed the video modules to test efficacy, usability, and likeability.

RESULTS

Three video modules, named evidence-based endoscopy (EBE), incorporating low fidelity simulation, and utilizing evidence-based medicine principles, were created. Eight fellows and 10 attendings completed the video modules and all quizzes and surveys. Mean test scores improved from before to after completing the video modules (56% to 92%; mean difference = -35%; 95% confidence interval, 27%-47%). Surveys indicated that the product was viewed favorably by participants, and that there is a strong desire for this type of educational product.

CONCLUSIONS

The EBE simulator is a unique, desirable, and effective educational platform based on evidence-based medicine principles that fills a gap in available tools for endoscopy education. Further studies are needed to assess whether EBE can aid in long-term knowledge retention and increase adherence to guideline recommendations.

AGA Clinical Practice Update on the Optimal Management of the Malignant Alimentary Tract Obstruction: Expert Review

BACKGROUND & AIMS

The purpose of this expert review is to describe the current methodologies available to manage malignant alimentary tract obstructions as well the evidence behind the various methods (including their efficacy and safety), indications, and appropriate timing of interventions.

METHODS

This is not a formal systematic review but is based on a review of the literature to provide best practice advice statements. No formal rating of the quality of evidence or strength of recommendation is carried out. BEST PRACTICE ADVICE 1: For all patients with alimentary tract obstruction, the decision about specific interventions should be made in a multidisciplinary setting including oncologists, surgeons, and endoscopists and take into account the characteristics of the obstruction, patient's expectations, prognosis, expected subsequent therapies, and functional status. BEST PRACTICE ADVICE 2: For patients who present with esophageal obstruction from esophageal cancer and who are potential candidates for resection or chemoradiation, clinicians should not routinely insert a self-expanding metal stent (SEMS) without multidisciplinary review because of high rates of stent migration, higher morbidity and mortality, and potentially lower R0 (microscopically negative margins) resection rates. BEST PRACTICE ADVICE 3: For patients who present with esophageal obstruction from esophageal cancer who are potential candidates for resection and who have concerns of malnutrition, clinicians may consider the use of enteral feeding tubes (via nasogastric or percutaneous route). Clinicians should be aware of the potential risk of abdominal wall tumor seeding as well as making subsequent gastric conduit formation difficult with percutaneous endoscopic gastrostomy placement. BEST PRACTICE ADVICE 4: For patients who present with esophageal obstruction from esophageal cancer who are not candidates for resection, clinicians should consider either SEMS insertion or brachytherapy as sole therapy or in combination. Clinicians should not consider the use of laser therapy or photodynamic therapy because of the lack of evidence of better outcomes and superior alternatives. BEST PRACTICE ADVICE 5: For patients with malignant esophageal obstruction who are undergoing SEMS placement, clinicians should use a fully covered or partially covered SEMS and not an uncovered SEMS, with consideration of a stent-anchoring/fixation method. BEST PRACTICE ADVICE 6: For patients with gastric outlet obstruction who have a life expectancy greater than 2 months, have good functional status, and who are surgically fit, surgical gastrojejunostomy should be considered. BEST PRACTICE ADVICE 7: For patients with gastric outlet obstruction who are undergoing surgical gastrojejunostomy, a laparoscopic approach is favored over an open approach because of lower blood loss and shorter hospital stay. BEST PRACTICE ADVICE 8: For patients with gastric outlet obstruction who are not candidates for gastrojejunostomy (surgical or endoscopic ultrasound-guided), clinicians should consider the insertion of an enteral stent. BEST PRACTICE ADVICE 9: Enteral stents should not be used in patients with multiple luminal obstructions or severely impaired gastric motility because of the limited benefit in these scenarios. Clinicians can consider placement of a venting gastrostomy in these patients. BEST PRACTICE ADVICE 10: Depending on the experience of the endoscopist, endoscopic ultrasound-guided gastrojejunostomy is an acceptable alternative to surgical gastrojejunostomy and enteral stent placement. Clinicians should be aware that there are currently no dedicated Food and Drug Administration-approved devices for endoscopic ultrasound-guided gastrojejunostomy. BEST PRACTICE ADVICE 11: For patients with malignant colonic obstruction who are candidates for resection, insertion of SEMS is a reasonable choice as a "bridge to surgery" to allow for one-stage, elective resection. BEST PRACTICE ADVICE 12: For patients with malignant colonic obstruction who are not candidates for resection, either SEMS placement or a diverting colostomy are reasonable choices depending on the patient's goals and functional status. BEST PRACTICE ADVICE 13: SEMS is a reasonable option for patients with proximal (or right-sided) malignant obstructions, both as a "bridge to surgery" and in the palliative setting. BEST PRACTICE ADVICE 14: SEMS placement is a reasonable alternative for patients with extracolonic malignancy who are not candidates for surgery, although their placement is more technically challenging, clinical success rates are more variable, and complications (including stent migration) are more frequent.

Massively Parallel Sequencing of Esophageal Brushings Enables an Aneuploidy-Based Classification of Patients With Barrett's Esophagus

BACKGROUND & AIMS

Aneuploidy has been proposed as a tool to assess progression in patients with Barrett's esophagus (BE), but has heretofore required multiple biopsies. We assessed whether a single esophageal brushing that widely sampled the esophagus could be combined with massively parallel sequencing to characterize aneuploidy and identify patients with disease progression to dysplasia or cancer.

METHODS

Esophageal brushings were obtained from patients without BE, with non-dysplastic BE (NDBE), low-grade dysplasia (LGD), high-grade dysplasia (HGD), or adenocarcinoma (EAC). To assess aneuploidy, we used RealSeqS, a technique that uses a single primer pair to interrogate ∼350,000 genome-spanning regions and identify specific chromosome arm alterations. A classifier to distinguish NDBE from EAC was trained on results from 79 patients. An independent validation cohort of 268 subjects was used to test the classifier at distinguishing patients at successive phases of BE progression.

RESULTS

Aneuploidy progression was associated with gains of 1q, 12p, and 20q and losses on 9p and 17p. The entire chromosome 8q was often gained in NDBE, whereas focal gain of 8q24 was identified only when there was dysplasia. Among validation subjects, a classifier incorporating these features with a global measure of aneuploidy scored positive in 96% of EAC, 68% of HGD, but only 7% of NDBE.

CONCLUSIONS

RealSeqS analysis of esophageal brushings provides a practical and sensitive method to determine aneuploidy in BE patients. It identifies specific chromosome changes that occur early in NDBE and others that occur late and mark progression to dysplasia. The clinical implications of this approach can now be tested in prospective trials.

Identifying DNA methylation biomarkers for non-endoscopic detection of Barrett's esophagus

We report a biomarker-based non-endoscopic method for detecting Barrett's esophagus (BE) based on detecting methylated DNAs retrieved via a swallowable balloon-based esophageal sampling device. BE is the precursor of, and a major recognized risk factor for, developing esophageal adenocarcinoma. Endoscopy, the current standard for BE detection, is not cost-effective for population screening. We performed genome-wide screening to ascertain regions targeted for recurrent aberrant cytosine methylation in BE, identifying high-frequency methylation within the CCNA1 locus. We tested CCNA1 DNA methylation as a BE biomarker in cytology brushings of the distal esophagus from 173 individuals with or without BE. CCNA1 DNA methylation demonstrated an area under the curve of 0.95 for discriminating BE-related metaplasia and neoplasia cases versus normal individuals, performing identically to methylation of VIM DNA, an established BE biomarker. When combined, the resulting two biomarker panel was 95% sensitive and 91% specific. These results were replicated in an independent validation cohort of 149 individuals who were assayed using the same cutoff values for test positivity established in the training population. To progress toward non-endoscopic esophageal screening, we engineered a well-tolerated, swallowable, encapsulated balloon device able to selectively sample the distal esophagus within 5 min. In balloon samples from 86 individuals, tests of CCNA1 plus VIM DNA methylation detected BE metaplasia with 90.3% sensitivity and 91.7% specificity. Combining the balloon sampling device with molecular assays of CCNA1 plus VIM DNA methylation enables an efficient, well-tolerated, sensitive, and specific method of screening at-risk populations for BE.

A Prospective Multicenter Study Evaluating Learning Curves and Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography Among Advanced Endoscopy Trainees: The Rapid Assessment of Trainee Endoscopy Skills Study

BACKGROUND & AIMS

On the basis of the Next Accreditation System, trainee assessment should occur on a continuous basis with individualized feedback. We aimed to validate endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) learning curves among advanced endoscopy trainees (AETs) by using a large national sample of training programs and to develop a centralized database that allows assessment of performance in relation to peers.

METHODS

ASGE recognized training programs were invited to participate, and AETs were graded on ERCP and EUS exams by using a validated competency assessment tool that assesses technical and cognitive competence in a continuous fashion. Grading for each skill was done by using a 4-point scoring system, and a comprehensive data collection and reporting system was built to create learning curves by using cumulative sum analysis. Individual results and benchmarking to peers were shared with AETs and trainers quarterly.

RESULTS

Of the 62 programs invited, 20 programs and 22 AETs participated in this study. At the end of training, median number of EUS and ERCP performed/AET was 300 (range, 155-650) and 350 (125-500), respectively. Overall, 3786 exams were graded (EUS, 1137; ERCP-biliary, 2280; ERCP-pancreatic, 369). Learning curves for individual end points and overall technical/cognitive aspects in EUS and ERCP demonstrated substantial variability and were successfully shared with all programs. The majority of trainees achieved overall technical (EUS, 82%; ERCP, 60%) and cognitive (EUS, 76%; ERCP, 100%) competence at conclusion of training.

CONCLUSIONS

These results demonstrate the feasibility of establishing a centralized database to report individualized learning curves and confirm the substantial variability in time to achieve competence among AETs in EUS and ERCP. ClinicalTrials.gov: NCT02509416.

Linkage and related analyses of Barrett's esophagus and its associated adenocarcinomas

Background

Familial aggregation and segregation analysis studies have provided evidence of a genetic basis for esophageal adenocarcinoma (EAC) and its premalignant precursor, Barrett's esophagus (BE). We aim to demonstrate the utility of linkage analysis to identify the genomic regions that might contain the genetic variants that predispose individuals to this complex trait (BE and EAC).

Methods

We genotyped 144 individuals in 42 multiplex pedigrees chosen from 1000 singly ascertained BE/EAC pedigrees, and performed both model‐based and model‐free linkage analyses, using S.A.G.E. and other software. Segregation models were fitted, from the data on both the 42 pedigrees and the 1000 pedigrees, to determine parameters for performing model‐based linkage analysis. Model‐based and model‐free linkage analyses were conducted in two sets of pedigrees: the 42 pedigrees and a subset of 18 pedigrees with female affected members that are expected to be more genetically homogeneous. Genome‐wide associations were also tested in these families.

Results

Linkage analyses on the 42 pedigrees identified several regions consistently suggestive of linkage by different linkage analysis methods on chromosomes 2q31, 12q23, and 4p14. A linkage on 15q26 is the only consistent linkage region identified in the 18 female‐affected pedigrees, in which the linkage signal is higher than in the 42 pedigrees. Other tentative linkage signals are also reported.

Conclusion

Our linkage study of BE/EAC pedigrees identified linkage regions on chromosomes 2, 4, 12, and 15, with some reported associations located within our linkage peaks. Our linkage results can help prioritize association tests to delineate the genetic determinants underlying susceptibility to BE and EAC.

Predicting Barrett's Esophagus in Families: An Esophagus Translational Research Network (BETRNet) Model Fitting Clinical Data to a Familial Paradigm

BACKGROUND

Barrett's esophagus is often asymptomatic and only a small portion of Barrett's esophagus patients are currently diagnosed and under surveillance. Therefore, it is important to develop risk prediction models to identify high-risk individuals with Barrett's esophagus. Familial aggregation of Barrett's esophagus and esophageal adenocarcinoma, and the increased risk of esophageal adenocarcinoma for individuals with a family history, raise the necessity of including genetic factors in the prediction model. Methods to determine risk prediction models using both risk covariates and ascertained family data are not well developed.

METHODS

We developed a Barrett's Esophagus Translational Research Network (BETRNet) risk prediction model from 787 singly ascertained Barrett's esophagus pedigrees and 92 multiplex Barrett's esophagus pedigrees, fitting a multivariate logistic model that incorporates family history and clinical risk factors. The eight risk factors, age, sex, education level, parental status, smoking, heartburn frequency, regurgitation frequency, and use of acid suppressant, were included in the model. The prediction accuracy was evaluated on the training dataset and an independent validation dataset of 643 multiplex Barrett's esophagus pedigrees.

RESULTS

Our results indicate family information helps to predict Barrett's esophagus risk, and predicting in families improves both prediction calibration and discrimination accuracy.

CONCLUSIONS

Our model can predict Barrett's esophagus risk for anyone with family members known to have, or not have, had Barrett's esophagus. It can predict risk for unrelated individuals without knowing any relatives' information.

IMPACT

Our prediction model will shed light on effectively identifying high-risk individuals for Barrett's esophagus screening and surveillance, consequently allowing intervention at an early stage, and reducing mortality from esophageal adenocarcinoma. Cancer Epidemiol Biomarkers Prev; 25(5); 727-35. ©2016 AACR.

Prevalence and clinical significance of pancreatic cysts associated with cysts in other organs

BACKGROUND AND AIM

Von Hippel-Lindau disease is associated with serous cysts in the pancreas and kidneys. In this study we determined the prevalence of pancreatic cysts occurring concurrently with other abdominal cysts and tested the hypothesis that these patients might represent a forme fruste of Von Hippel-Lindau disease and be more likely to be serous cysts.

METHODS

A retrospective chart review of patients undergoing endoscopic ultrasound of pancreatic cysts.

RESULTS

A total of 156 patients were included in the study. Eighty-five patients (54.8%) had cyst(s) in the pancreas and at least one other intra-abdominal cyst. These cysts included 24 (27.9%) serous cysts, 30 (34.9%), mucinous cysts, 6 (7%) adenocarcinoma and 25 (29.4%) unknowns. Seventy-one patients (45.2%) had isolated pancreatic cysts. These included 17 (23.9%) serous cysts, 28 (39.5%) mucinous cysts, 4 (5.6%) adenocarcinoma and 22 (31%) unknowns. The odds of serous cysts with concurrent extra-pancreatic and pancreatic cysts compared to odds of serous cysts with pancreatic cysts alone were 1.3 (95% CI: 0.6-2.9).

CONCLUSIONS

Pancreatic cysts are associated with cysts in other abdominal organs in 54.8% patients. The prevalence of serous cysts was not higher amongst individuals with multiple organ cysts compared to those with only pancreatic cysts.

Feasibility of radiofrequency ablation for the treatment of chronic radiation proctitis

BACKGROUND

Chronic radiation proctitis can be difficult to manage. Radiofrequency ablation has recently been shown to be effective in the management of gastric antral vascular ectasia and Barrett's esophagus, but its utility in the treatment of chronic radiation proctitis is undetermined.

METHOD

A 77-year-old man with extensive chronic radiation proctitis had continued bleeding despite argon plasma coagulation. The HALO(90) radiofrequency system (BARRX Medical, Sunnyvale, CA) was used for treatment regions of proctitis at an energy density of 12 J/cm(2).

RESULTS

At monthly intervals, over 3 months, radiofrequency ablation was performed with a mean of 7 regions ablated at a time. The mean treatment time was 29 minutes. There was no significant bleeding after the first treatment session. The patient was symptom free at 6 months follow-up with minimal evidence of residual mucosal abnormalities.

CONCLUSIONS

Radiofrequency ablation appears feasible for treatment of refractory chronic radiation proctitis, with further studies required.

Ultrathin esophagoscopy in screening for Barrett's esophagus at a Veterans Administration Hospital: easy access does not lead to referrals

OBJECTIVE

Unsedated, ultrathin esophagoscopy has been shown to be tolerable, safe, and accurate. Survey data have suggested that accessibility of unsedated esophagoscopy would increase referrals for Barrett's esophagus (BE) screening. Our purpose was to evaluate primary-care physician referrals for BE screening when unsedated esophagoscopy is made available.

METHODS

We studied primary-care referrals for unsedated esophagoscopy in a VA internal medicine clinic. Patients over age 45 with chronic heartburn for >5 yr or >3 times weekly and who had no previous EGD were eligible for screening with unsedated esophagoscopy. All primary providers received a 15-min education session on screening. Baseline referral rate was determined retrospectively. Longitudinal data were then collected during three phases of the study: (a) primary provider-initiated referrals, (b) primary provider-initiated referrals with weekly reminders from investigators, and (c) investigator recruitment.

RESULTS

Baseline referral rate averaged 0.5 patients per month. Availability of unsedated esophagoscopy and an education session increased the rate of referral to 0.66 patients per month. Weekly reminders to primary physicians further increased the rate to 1.33 referrals per month. Investigator recruitment produced a rate of 2.67 referrals per month. Of the 77 patients offered screening, 25 (32%) declined. Of the 52 patients screened, three (5.8%) were diagnosed with BE.

CONCLUSIONS

Accessibility of unsedated esophagoscopy itself does not lead to a large increase in the number of primary care referrals for BE screening. Factors that prevent primary care physicians from referring patients for screening need to be identified and effective interventions to change referral patterns need to be implemented for unsedated screening programs to be successful.

Natural orifice transluminal endoscopic surgery (NOTES) as a diagnostic tool in the intensive care unit

BACKGROUND

Autopsy studies confirm that many intensive care unit (ICU) patients die from unrecognized sources of abdominal sepsis or ischemia. Computed tomography (CT) scans can be of limited use for these diagnoses and difficult to obtain in critically ill patients who require significant support for transport. Bedside laparoscopy has been described but still is cumbersome to perform. Bedside flexible endoscopy as a diagnostic tool or for placement of gastrostomy tubes is a standard ICU procedure. Natural orifice transluminal endoscopic surgery (NOTES) can provide access to the peritoneal cavity as a bedside procedure and may decrease the number of patients with unrecognized intra-abdominal catastrophic events.

METHODS

Pigs were anesthetized and peritoneal access with the flexible endoscope was obtained using a guidewire, needle knife cautery, and balloon dilatation. The transgastric endoscope was used to explore all quadrants of the abdominal cavity. The small bowel was visualized to complete the exploration. The transgastric access location was then managed with the use of a gastrostomy tube. The animals were euthanized and analyzed.

RESULTS

Eight pigs were studied and complete abdominal exploration, including diaphragm visualization, was possible in all cases. Endoscopy-guided biopsies were performed, adhesions lysed, and the gallbladder successfully drained percutaneously. The small bowel was run successfully with percutaneous needlescopic suture graspers.

CONCLUSIONS

These animal studies support the concept that NOTES, with management of the gastric opening with a gastrostomy tube, may be another approach for finding unrecognized sources of abdominal sepsis or mesenteric ischemia in difficult ICU patients. These encouraging results warrant a prospective human trial to assess safety and efficacy.

A reliable method for monitoring intraabdominal pressure during natural orifice translumenal endoscopic surgery

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) provides surgical access to the peritoneal cavity without skin incisions. The NOTES procedure requires pneumoperitoneum for visualization and manipulation of abdominal organs, similar to laparoscopy. Accurate measurement of the pneumoperitoneum pressure is essential to avoid potentially deleterious effects of intraabdominal compartment syndrome. A reliable method for monitoring pneumoperitoneum pressures during NOTES has not been identified. This study evaluated several methods of monitoring intraabdominal pressures with a standard gastroscope during NOTES.

METHODS

Four female pigs (25 kg) were sedated, and a single-channel gastroscope was passed transgastrically into the peritoneal cavity. Pneumoperitoneum was achieved via a pressure insufflator through a percutaneous, intraperitoneal 14-gauge catheter. Three other pressures were recorded via separate catheters. First, a 14-gauge percutaneous catheter passed intraperitoneally measured true intraabdominal pressure. Second, a 14-gauge tube attached to the endoscope was used to measure endoscope tip pressure. The third pressure transducer was connected directly to the accessory channel of the endoscope. The abdomen was insufflated to a range of pressures (10-30 mmHg), and simultaneous pressures were recorded from all three pressure sensors.

RESULTS

Pressure correlation curves were developed for all animals across all intraperitoneal pressures (mean error, -4.25 to -1 mmHg). Endoscope tip pressures correlated with biopsy channel pressures (R2 = 0.99). Biopsy channel and endoscope tip pressures fit a least-squares linear model to predict actual intraabdominal pressure (R = 0.99 for both). Both scope tip and biopsy channel port pressures were strongly correlative with true intraabdominal pressures (R2 = 0.98 and R2 = 0.99, respectively).

CONCLUSION

This study demonstrates that monitoring pressure through an endoscope is reliable and predictive of true intraabdominal pressure. Gastroscope pressure monitoring is a useful adjunct to NOTES. Future NOTES procedures should incorporate continuous intraabdominal pressure monitoring to avoid the potentially deleterious effects of pneumoperitoneum during NOTES. This can be achieved by the integration of pressure-monitoring capabilities into gastroscopes.

A primer on natural orifice transluminal endoscopic surgery: building a new paradigm

Access to the abdominal cavity is required for diagnostic and therapeutic endeavors for a variety of medical and surgical diseases. Historically, abdominal access has required a formal laparotomy to provide adequate exposure. Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery that eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. During NOTES, commercially available flexible video endoscopes are used to create a controlled transvisceral incision via natural orifice access to enter the peritoneal cavity. Common incision-related complications such as wound infections, incisional hernias, postoperative pain, aesthetic disdain, and adhesions could be minimized or eliminated by NOTES. NOTES has evolved from more than 2 centuries of technological innovations and continued growth in the field of surgical endoscopy. Innovative surgical endoscopists have slowly developed means to surpass the constraints of the gastrointestinal lumen by using a flexible endoscope. The future of surgical endoscopy may be the shared entity of NOTES, which further integrates endoscopy, gastroenterology, and minimally invasive and general surgery. Although the promise of NOTES is electrifying to surgeons and endoscopists, several key issues need to be characterized prior to the incorporation of NOTES into routine practice. This article reviews the status, contemporary body of literature, limitations, and potential future implications accompanying the development of NOTES.

Diaphragm pacing with natural orifice transluminal endoscopic surgery: potential for difficult-to-wean intensive care unit patients

BACKGROUND

Up to 50% of the patients in the intensive care unit (ICU) require mechanical ventilation, with 20% requiring the use of a ventilator for more than 7 days. More than 40% of this time is spent weaning the patient from mechanical ventilation. Failure to wean from mechanical ventilation can in part be attributable to rapid onset of diaphragm atrophy, barotrauma, posterior lobe atelectasis, and impaired hemodynamics, which are normally improved by maintaining a more natural negative chest pressure. The authors have previously shown that laparoscopic implantation of a diaphragm pacing system benefits selected patients. They now propose that an acute ventilator assist with interventional neurostimulation of the diaphragm in the ICU is feasible and could facilitate the weaning of ICU patients from mechanical ventilation. Natural orifice transluminal endoscopic surgery (NOTES) has the potential to expand the benefits of the diaphragm pacing system to this acute patient population by allowing it to be performed at the bedside similarly to insertion of the common gastrostomy tube. This study evaluates the feasibility of this approach in a porcine model.

METHODS

Pigs were anesthetized, and peritoneal access with the flexible endoscope was obtained using a guidewire, needle knife cautery, and balloon dilation. The diaphragm was mapped using a novel endoscopic electrostimulation catheter to locate the motor point (where stimulation provides complete contraction of the diaphragm). An intramuscular electrode then was placed at the motor point with a percutaneous needle. The gastrotomy was managed with a gastrostomy tube.

RESULTS

Four pigs were studied, and the endoscopic mapping instrument was able to map the diaphragm to identify the motor point. In one animal, a percutaneous electrode was placed into the motor point under transgastric endoscopic visualization, and the diaphragm could be paced in conjunction with mechanical ventilation.

CONCLUSIONS

These animal studies demonstrate the feasibility of transgastric mapping of the diaphragm and implantation of a percutaneous electrode for therapeutic diaphragmatic stimulation.

Gastroesophageal reflux symptoms in patients with adenocarcinoma of the esophagus or cardia

BACKGROUND

The efficacy of endoscopic screening for chronic gastroesophageal reflux symptoms of heartburn and regurgitation in adult subjects depends on the sensitivity of this strategy for detecting Barrett esophagus in subjects before the development of adenocarcinoma of the esophagus or cardia. The aim of the current study was to determine what proportion of patients with cancer of the esophagus or cardia would have been candidates for a screening endoscopy before their cancer diagnosis based on the presence and duration of preceding reflux symptoms.

METHODS

All patients with adenocarcinoma of the esophagus, adenocarcinoma of the cardia, or long-segment Barrett esophagus presenting for endoscopy at 4 tertiary care and 2 Veterans Affairs (VA) hospitals were given a previously validated questionnaire to determine their recall of common gastroesophageal reflux symptoms.

RESULTS

The study population of 375 subjects consisted primarily of 294 (78%) white men. Only 67 of 110 patients (61%) with adenocarcinoma of the esophagus and 8 of 21 patients (38%) with adenocarcinoma of the cardia recalled symptoms of heartburn or regurgitation being present for >5 years before their diagnosis of cancer. Only 40 of 110 patients (36%) with adenocarcinoma of the esophagus and 5 of 21 patients (24%) with adenocarcinoma of the cardia recalled weekly symptoms being present for >5 years before their cancer diagnosis. Of the 244 patients with Barrett esophagus, 170 (70%) recalled heartburn or regurgitation for >5 years and 89 patients (37%) recalled weekly symptoms for >5 years.

CONCLUSIONS

Current practice, which uses a screening strategy of performing endoscopy in patients with >5 years of heartburn or regurgitation, can detect Barrett epithelium in only a limited proportion of those patients at risk for developing adenocarcinoma of the esophagus or adenocarcinoma of the cardia.

Primary care physician attitudes toward endoscopic screening for GERD symptoms and unsedated esophagoscopy

BACKGROUND

Current guidelines recommend consideration of screening patients with chronic GERD for Barrett's esophagus (BE). Unsedated esophagoscopy (UE) is a less costly alternative to standard EGD for identifying BE. The aim of this study was to determine the indications for EGD referral, the barriers to screening, and the interest in performing UE.

METHODS

A one-page survey was mailed to a random sample of 500 family practitioners and 500 internists. This sample was obtained from the American Academy of Family Physicians and American Society of Internal Medicine (500 from each organization).

RESULTS

The overall response rate was 54%. The majority (78%) refer more than 50% of their GERD patients for EGD; however, 34% also refer more than 10% of their patients for barium studies. Primary care physicians cited alarm symptoms, refractory symptoms, and chronicity and severity of symptoms as the major indications for referral for EGD. Gender, age, obesity, and tobacco use were cited less frequently. Cost of endoscopy, poor patient acceptance, and lack of evidence were the most common reasons cited for not referring for EGD. A majority of respondents (62%) indicated that the availability of UE would increase referral for the procedure, and 52% would be willing to perform UE in their office.

CONCLUSIONS

Severe, refractory, and chronic symptoms are the primary reasons for endoscopic referral from primary care physicians who manage patients with GERD. Other risk factors for BE, such as gender and age, do not appear to be important determinants for endoscopic referral. Further evaluation of UE as a mechanism to increase screening for BE in primary care patients is merited.

Identification of Barrett's esophagus in relatives by endoscopic screening

AIM

Familial aggregation of Barrett's esophagus and its associated cancers has been termed familial Barrett's esophagus (FBE). The aim of the study was to determine whether endoscopic screening would identify Barrett's esophagus (BE) in relatives of probands with BE or esophageal adenocarcinoma (EAC).

METHODS

All living first-degree relatives of patients with long segment BE or EAC presenting to the endoscopy suite of two academic hospitals were sent validated questionnaires inquiring about gastroesophageal reflux symptoms and prior endoscopic evaluation. First-degree relatives of affected probands or affected relatives who reported no prior upper endoscopy were offered screening unsedated esophagoscopy. Relatives with chronic gastroesophageal reflux symptoms were also offered an alternative of conventional sedated upper endoscopy. The yield of screening endoscopy was measured. Screening endoscopy findings were then compared between family members of known FBE patients and those with "isolated" disease.

RESULTS

One hundred and ninety-eight relatives from 69 families, 23 known FBE probands and 46 probands with apparently "isolated" disease, were enrolled. Forty relatives (29 FBE relatives and 11 relatives of probands with "isolated" disease) reported prior upper endoscopy. Screening upper endoscopies performed on 62 (25 FBE and 37 "isolated" disease relatives) of the remaining 158 relatives identified Barrett's epithelium in 13 (21%). Compared to probands with apparently "isolated" disease, Barrett's epithelium (EAC, BE, or SSBE) was identified significantly more often in siblings and offspring of FBE probands, p</= 0.05. Endoscopic screening of relatives of FBE probands identified a multigeneration multiplex FBE pedigree consistent with an autosomally dominant inherited trait. Endoscopic screening of relatives of probands with reported "isolated" diseased did not identify any new FBE pedigrees.

CONCLUSIONS

Endoscopy identified EAC, long-segment BE, and short-segment BE in a substantial proportion of first-degree relatives of affected members of FBE families. A familial susceptibility to develop Barrett's epithelium appears to be present in a subset of patients with BE and EAC.

Prospective evaluation of 4-mm diameter endoscopes for esophagoscopy in sedated and unsedated patients

BACKGROUND

Unsedated esophagoscopy with small-diameter endoscopes is generally well tolerated but of limited sensitivity for the diagnosis of esophageal mucosal disease. This study evaluated the sensitivity of esophagoscopy performed with new 4-mm diameter prototype battery-powered and video endoscopes. Patient tolerance for an unsedated examination with the 4-mm endoscopes was assessed and the performance characteristics of the battery-powered and video 4-mm endoscopes were compared.

METHODS

Patients referred for EGD were recruited to undergo an additional examination with a 4-mm endoscope. A prototype 60-cm long, 4-mm diameter battery-powered fiberoptic esophagoscope was used in the first 24 patients and a prototype 60-cm long, 4-mm diameter video esophagoscope in the next 27 patients. Examiners who were unaware of patient history and procedure indications recorded esophageal findings, ease of intubation, optical quality (5-point visual scale), and time for examination of the esophagus and then recorded esophageal findings after the standard EGD.

RESULTS

The sensitivity, specificity, and accuracy for identification of Barrett's esophagus was 100%; overall sensitivity, accuracy, and specificity for detecting esophageal lesions were, respectively, 91%, 98%, and 99%. Patient tolerance (assessed by symptom scores for choking, pain, and discomfort) and acceptability of unsedated esophagoscopy with the 4-mm diameter instruments were significantly better than in a historical group of patients examined with a 3-mm diameter endoscope. The optical quality of video endoscope was rated as superior to that of battery-powered endoscope, and esophageal examination was performed significantly quicker with the video versus the battery-powered endoscope (68 vs. 137 seconds; p = 0.001).

CONCLUSIONS

Unsedated esophagoscopy with 4-mm diameter endoscopes may be an alternative to EGD for screening for Barrett's esophagus. Given the current state of endoscopic technology, a minimum diameter of 4 mm is required for satisfactory esophageal imaging.

Familial aggregation of Barrett's oesophagus, oesophageal adenocarcinoma, and oesophagogastric junctional adenocarcinoma in Caucasian adults

BACKGROUND

Although familial clusters of Barrett's oesophagus and oesophageal adenocarcinoma have been reported, a familial predisposition to these diseases has not been systematically investigated.

AIMS

To determine whether Barrett's oesophagus and oesophageal (or oesophagogastric junctional) adenocarcinoma aggregate in families.

PATIENTS AND METHODS

A structured questionnaire eliciting details on reflux symptoms, exposure history, and family history was given to Caucasian case (n=58) subjects with Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma, and to Caucasian control (n=106) subjects with symptomatic gastro-oesophageal reflux disease without Barrett's oesophagus. Reported diagnoses of family members were confirmed by review of medical records.

RESULTS

The presence of a positive family history (that is, first or second degree relative with Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma) was significantly higher among case subjects compared with controls (24% v 5%; p<0.005). Case subjects were more likely to be older (p<0.001) and male (74% v 43% male; p<0.0005) compared with control subjects. In a multivariate logistic regression analysis, family history was independently associated with the presence of Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma (odds ratio 12.23, 95% confidence interval 3.34-44.76) after adjusting for age, sex, and the presence of obesity 10 or more years prior to study enrollment.

CONCLUSIONS

Individuals with Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma are more likely to have a positive family history of Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma than individuals without Barrett's oesophagus, oesophageal adenocarcinoma, or oesophagogastric junctional adenocarcinoma. A positive family history should be considered when making decisions about screening endoscopy in patients with symptoms of gastro-oesophageal reflux.

Accuracy of a narrow-diameter battery-powered endoscope in sedated and unsedated patients

BACKGROUND

Esophagoscopy with a portable battery-powered endoscope could provide a safe, inexpensive, and minimally invasive way to screen for Barrett's esophagus or esophageal varices. The use of such an instrument in an unsedated fashion has not been previously evaluated.

METHODS

Patients referred for an EGD were recruited to undergo an additional examination with the battery-powered endoscope before EGD. In phase 1, (n = 42) patients received conscious sedation before the battery-powered endoscopic examination. In phase 2, (n = 56) patients were not sedated and were given the option of a peroral (n = 43) or transnasal (n = 13) endoscopy. Examiners were blinded to patient history and procedure indications. Esophageal findings, ease of intubation, optical quality, and patient comfort for the battery-powered endoscope and standard EGD were recorded by the endoscopist.

RESULTS

Ninety-eight patients (60 men, 38 women, mean age 53 years) were recruited. The sensitivity for detecting Barrett's esophagus, esophageal tumors, and esophageal varices was 54.5%, 66.7%, and 80%, respectively. Ease of intubation and patient comfort as perceived by the endoscopist were not significantly different between the battery-powered endoscope and EGD. Optical quality was ranked as less than 4 (on a 5-point scale with 5 = standard EGD and 1 = poor) in 42% of battery-powered endoscopic examinations. There were no complications.

CONCLUSION

The accuracy of esophageal examination with a 3.1-mm endoscope is substantially inferior to standard EGD. Thus, the battery-powered endoscope would not be useful for screening patients for Barrett's esophagus or varices unless improvements in optical quality and visualization are made.