Computer-aided diagnosis improves characterization of Barrett's neoplasia by general endoscopists (with video).

BACKGROUND AND AIMS: Characterization of visible abnormalities in patients with Barrett's esophagus (BE) can be challenging, especially for inexperienced endoscopists. This results in suboptimal diagnostic accuracy and poor interobserver agreement. Computer-aided diagnosis (CADx) systems may assist endoscopists. We aimed to develop, validate, and benchmark a CADx system for BE neoplasia. METHODS: The CADx system received pretraining with ImageNet and then consecutive domain-specific pretraining with GastroNet, which includes 5 million endoscopic images. It was subsequently trained and internally validated using 1758 narrow-band imaging (NBI) images of early BE neoplasia (352 patients) and 1838 NBI images of nondysplastic BE (173 patients) from 8 international centers. CADx was tested prospectively on corresponding image and video test sets with 30 cases (20 patients) of BE neoplasia and 60 cases (31 patients) of nondysplastic BE. The test set was benchmarked by 44 general endoscopists in 2 phases (phase 1, no CADx assistance; phase 2, with CADx assistance). Ten international BE experts provided additional benchmark performance. RESULTS: Stand-alone sensitivity and specificity of the CADx system were 100% and 98% for images and 93% and 96% for videos, respectively. CADx outperformed general endoscopists without CADx assistance in terms of sensitivity (P = .04). Sensitivity and specificity of general endoscopists increased from 84% to 96% and 90% to 98% with CAD assistance (P < .001). CADx assistance increased endoscopists' confidence in characterization (P < .001). CADx performance was similar to that of the BE experts. CONCLUSIONS: CADx assistance significantly increased characterization performance of BE neoplasia by general endoscopists to the level of expert endoscopists. The use of this CADx system may thereby improve daily Barrett surveillance.

Incidence and Prediction of Unrelated Mortality After Successful Endoscopic Eradication Therapy for Barrett's Neoplasia.

BACKGROUND & AIMS: Follow-up (FU) strategies after endoscopic eradication therapy (EET) for Barrett's neoplasia do not consider the risk of mortality from causes other than esophageal adenocarcinoma (EAC). We aimed to evaluate this risk during long-term FU, and to assess whether the Charlson Comorbidity Index (CCI) can predict mortality. METHODS: We included all patients with successful EET from the nationwide Barrett registry in the Netherlands. Data were merged with National Statistics for accurate mortality data. We evaluated annual mortality rates (AMRs, per 1000 person-years) and standardized mortality ratio for other-cause mortality. Performance of the CCI was evaluated by discrimination and calibration. RESULTS: We included 1154 patients with a mean age of 64 years (±9). During median 59 months (p25-p75 37-91; total 6375 person-years), 154 patients (13%) died from other causes than EAC (AMR, 24.1; 95% CI, 20.5-28.2), most commonly non-EAC cancers (n = 58), cardiovascular (n = 31), or pulmonary diseases (n = 26). Four patients died from recurrent EAC (AMR, 0.5; 95% CI, 0.1-1.4). Compared with the general Dutch population, mortality was significantly increased for patients in the lowest 3 age quartiles (ie, age <71 years). Validation of CCI in our population showed good discrimination (Concordance statistic, 0.78; 95% CI, 0.72-0.84) and fair calibration. CONCLUSION: The other-cause mortality risk after successful EET was more than 40 times higher (48; 95% CI, 15-99) than the risk of EAC-related mortality. Our findings reveal that younger post-EET patients exhibit a significantly reduced life expectancy when compared with the general population. Furthermore, they emphasize the strong predictive ability of CCI for long-term mortality after EET. This straightforward scoring system can inform decisions regarding personalized FU, including appropriate cessation timing. (NL7039).

Graft dilatation and Barrett's esophagus in adults after gastric pull-up and jejunal interposition for long-gap esophageal atresia.

BACKGROUND: Esophageal replacement (ER) with gastric pull-up (GPU) or jejunal interposition (JI) used to be the standard treatment for long-gap esophageal atresia (LGEA). Changes of the ER grafts on a macro- and microscopic level however, are unknown. AIM: To evaluate long-term clinical symptoms and anatomical and mucosal changes in adolescents and adults after ER for LGEA. METHODS: A cohort study was conducted including all LGEA patients ≥ 16 years who had undergone GPU or JI between 1985-2003 at two tertiary referral centers in the Netherlands. Patients underwent clinical assessment, contrast study and endoscopy with biopsy. Data was collected prospectively. Group differences between JI and GPU patients, and associations between different outcome measures were assessed using the Fisher's exact test for bivariate variables and the Mann-Whitney U-test for continuous variables. Differences with a P-value < 0.05 were considered statistically significant. RESULTS: Nine GPU patients and eleven JI patients were included. Median age at follow-up was 21.5 years and 24.4 years, respectively. Reflux was reported in six GPU patients (67%) vs four JI patients (36%) (P = 0.37). Dysphagia symptoms were reported in 64% of JI patients, compared to 22% of GPU patients (P = 0.09). Contrast studies showed dilatation of the jejunal graft in six patients (55%) and graft lengthening in four of these six patients. Endoscopy revealed columnar-lined esophagus in three GPU patients (33%) and intestinal metaplasia was histologically confirmed in two patients (22%). No association was found between reflux symptoms and macroscopic anomalies or intestinal metaplasia. Three GPU patients (33%) experienced severe feeding problems vs none in the JI group. The median body mass index of JI patients was 20.9 kg/m2 vs 19.5 kg/m2 in GPU patients (P = 0.08). CONCLUSION: The majority of GPU patients had reflux and intestinal metaplasia in 22%. The majority of JI patients had dysphagia and a dilated graft. Follow-up after ER for LGEA is essential.

Optical Biopsy of Dysplasia in Barrett's Oesophagus Assisted by Artificial Intelligence.

Optical biopsy in Barrett's oesophagus (BE) using endocytoscopy (EC) could optimize endoscopic screening. However, the identification of dysplasia is challenging due to the complex interpretation of the highly detailed images. Therefore, we assessed whether using artificial intelligence (AI) as second assessor could help gastroenterologists in interpreting endocytoscopic BE images. First, we prospectively videotaped 52 BE patients with EC. Then we trained and tested the AI pm distinct datasets drawn from 83,277 frames, developed an endocytoscopic BE classification system, and designed online training and testing modules. We invited two successive cohorts for these online modules: 10 endoscopists to validate the classification system and 12 gastroenterologists to evaluate AI as second assessor by providing six of them with the option to request AI assistance. Training the endoscopists in the classification system established an improved sensitivity of 90.0% (+32.67%, p < 0.001) and an accuracy of 77.67% (+13.0%, p = 0.020) compared with the baseline. However, these values deteriorated at follow-up (-16.67%, p < 0.001 and -8.0%, p = 0.009). Contrastingly, AI-assisted gastroenterologists maintained high sensitivity and accuracy at follow-up, subsequently outperforming the unassisted gastroenterologists (+20.0%, p = 0.025 and +12.22%, p = 0.05). Thus, best diagnostic scores for the identification of dysplasia emerged through human-machine collaboration between trained gastroenterologists with AI as the second assessor. Therefore, AI could support clinical implementation of optical biopsies through EC.

Towards a robust and compact deep learning system for primary detection of early Barrett's neoplasia: Initial image-based results of training on a multi-center retrospectively collected data set.

INTRODUCTION: Endoscopic detection of early neoplasia in Barrett's esophagus is difficult. Computer Aided Detection (CADe) systems may assist in neoplasia detection. The aim of this study was to report the first steps in the development of a CADe system for Barrett's neoplasia and to evaluate its performance when compared with endoscopists. METHODS: This CADe system was developed by a consortium, consisting of the Amsterdam University Medical Center, Eindhoven University of Technology, and 15 international hospitals. After pretraining, the system was trained and validated using 1.713 neoplastic (564 patients) and 2.707 non-dysplastic Barrett's esophagus (NDBE; 665 patients) images. Neoplastic lesions were delineated by 14 experts. The performance of the CADe system was tested on three independent test sets. Test set 1 (50 neoplastic and 150 NDBE images) contained subtle neoplastic lesions representing challenging cases and was benchmarked by 52 general endoscopists. Test set 2 (50 neoplastic and 50 NDBE images) contained a heterogeneous case-mix of neoplastic lesions, representing distribution in clinical practice. Test set 3 (50 neoplastic and 150 NDBE images) contained prospectively collected imagery. The main outcome was correct classification of the images in terms of sensitivity. RESULTS: The sensitivity of the CADe system on test set 1 was 84%. For general endoscopists, sensitivity was 63%, corresponding to a neoplasia miss-rate of one-third of neoplastic lesions and a potential relative increase in neoplasia detection of 33% for CADe-assisted detection. The sensitivity of the CADe system on test sets 2 and 3 was 100% and 88%, respectively. The specificity of the CADe system varied for the three test sets between 64% and 66%. CONCLUSION: This study describes the first steps towards the establishment of an unprecedented data infrastructure for using machine learning to improve the endoscopic detection of Barrett's neoplasia. The CADe system detected neoplasia reliably and outperformed a large group of endoscopists in terms of sensitivity.

Clinical Relevance of Random Biopsies From the Esophagogastric Junction After Complete Eradication of Barrett's Esophagus is Low.

BACKGROUND & AIMS: Although random histological sampling from the esophagogastric junction (EGJ) after complete eradication of Barrett's esophagus (BE) is recommended, its clinical relevance is questionable. This study aimed to assess the incidence and long-term outcomes of findings from random EGJ biopsies in a nationwide cohort with long-term follow-up. METHODS: We included all patients with successful endoscopic eradication therapy (EET), defined as complete endoscopic eradication of all visible BE (CE-BE), for early BE neoplasia from the Dutch registry. Patients were treated and followed-up in 9 expert centers according to a joint protocol. Outcomes included the incidence of intestinal metaplasia (IM) at the EGJ (EGJ-IM) and the association between IM and visible (dysplastic) BE recurrence. RESULTS: A total of 1154 patients were included with a median follow-up of 43 months (interquartile range, 22-69 months). At the time of CE-BE, persisting EGJ-IM was found in 7% of patients (78/1154), which was reproduced during further follow-up in 46% of patients (42/78). No significant association existed between persisting EGJ-IM at CE-BE and recurrent non-dysplastic or dysplastic BE (hazard ratio [HR], 1.15; 95% confidence interval [CI], 0.63-2.13 and HR, 0.73; 95% CI, 0.17-3.06, respectively). Among patients with no EGJ-IM at the time of CE-BE (1043/1154; 90%), EGJ-IM recurred in 7% (72/1043) after a median of 21 months (interquartile range, 15-36 months), and was reproduced during further follow-up in 26% of patients (19/72). No association was found between recurrent EGJ-IM and non-dysplastic or dysplastic recurrence (HR, 1.18; 95% CI, 0.67-2.06 and HR, 0.27; 95% CI, 0.04-1.96, respectively). CONCLUSION: Because EGJ-IM was not associated with a higher risk for recurrent disease, we recommend to consider abandoning random EGJ sampling after successful EET, under the condition that care is provided in expert centers, and the esophagus, including the EGJ, is carefully inspected (Netherlands Trial Register, NL7309).

Dysplastic Recurrence After Successful Treatment for Early Barrett's Neoplasia: Development and Validation of a Prediction Model.

BACKGROUND & AIMS: The combination of endoscopic resection and radiofrequency ablation is the treatment of choice for eradication of Barrett's esophagus (BE) with dysplasia and/or early cancer. Currently, there are no evidence-based recommendations on how to survey patients after successful treatment, and most patients undergo frequent follow-up endoscopies. We aimed to develop and externally validate a prediction model for visible dysplastic recurrence, which can be used to personalize surveillance after treatment. METHODS: We collected data from the Dutch Barrett Expert Center Registry, a nationwide registry that captures outcomes from all patients with BE undergoing endoscopic treatment in the Netherlands in a centralized care setting. We used predictors related to demographics, severity of reflux, histologic status at baseline, and treatment characteristics. We built a Fine and Gray survival model with least absolute shrinkage and selection operator penalization to predict the incidence of visible dysplastic recurrence after initial successful treatment. The model was validated externally in patients with BE treated in Switzerland and Belgium. RESULTS: A total of 1154 patients with complete BE eradication were included for model building. During a mean endoscopic follow-up of 4 years, 38 patients developed recurrent disease (1.0%/person-year). The following characteristics were independently associated with recurrence (strongest to weakest predictor): a new visible lesion during treatment phase, higher number of endoscopic resection treatments, male sex, increasing BE length, high-grade dysplasia or cancer at baseline, and younger age. External validation showed a C-statistic of 0.91 (95% confidence interval, 0.86-0.94) with good calibration. CONCLUSIONS: This is the first externally validated model to predict visible dysplastic recurrence after successful endoscopic eradication treatment of BE with dysplasia or early cancer. On external validation, our model has good discrimination and calibration. This model can help clinicians and patients to determine a personalized follow-up strategy.

Analysis of metastases rates during follow-up after endoscopic resection of early "high-risk" esophageal adenocarcinoma.

BACKGROUND AND AIMS: After endoscopic resection (ER) of early esophageal adenocarcinoma (EAC), the optimal management of patients with high-risk histologic features for lymph node metastases (ie, submucosal invasion, poor differentiation grade, or lymphovascular invasion) remains unclear. We aimed to evaluate outcomes of endoscopic follow-up after ER for high-risk EAC. METHODS: For this retrospective cohort study, data were collected from all Dutch patients managed with endoscopic follow-up (endoscopy, EUS) after ER for high-risk EAC between 2008 and 2019. We distinguished 3 groups: intramucosal cancers with high-risk features, submucosal cancers with low-risk features, and submucosal cancers with high-risk features. The primary outcome was the annual risk for metastases during follow-up, stratified for baseline histology. RESULTS: One hundred twenty patients met the selection criteria. Median follow-up was 29 months (interquartile range, 15-48). Metastases were observed in 5 of 25 (annual risk, 6.9%; 95% confidence interval [CI], 3.0-15) high-risk intramucosal cancers, 1 of 55 (annual risk, .7%; 95% CI, 0-4.0) low-risk submucosal cancers, and 3 of 40 (annual risk, 3.0%; 95% CI, 0-7.0) high-risk submucosal cancers. CONCLUSIONS: Whereas the annual metastasis rate for high-risk submucosal EAC (3.0%) was somewhat lower than expected in comparison with previous reported percentages, the annual metastasis rate of 6.9% for high-risk intramucosal EAC is new and worrisome. This calls for further prospective studies and suggests that strict follow-up of this small subgroup is warranted until prospective data are available.

Development and External Validation of a Model to Predict Complex Treatment After Radiofrequency Ablation for Barrett's Esophagus With Early Neoplasia.

BACKGROUND & AIMS: Endoscopic eradication therapy for Barrett's esophagus (BE)-related neoplasia is safe and leads to complete eradication in the majority of patients. However, a subgroup will experience a more complex treatment course with a risk for failure or disease progression. Early identification of these patients may improve patient counseling and treatment outcomes. We aimed to develop a prognostic model for a complex treatment course. METHODS: We collected data from a nationwide registry that captures outcomes for all patients undergoing endoscopic eradication therapy for early BE neoplasia. A complex treatment course was defined as neoplastic progression, treatment failure, or the need for endoscopic resection during the radiofrequency ablation treatment phase. We developed a prognostic model using logistic regression. We externally validated our model in an independent registry. RESULTS: A total of 1386 patients were included, of whom 78 (6%) had a complex treatment course. Our model identified patients with a BE length of 9 cm or longer with a visible lesion containing high-grade dysplasia/cancer, and patients with less than 50% squamous conversion after radiofrequency ablation were identified as high risk for a complex treatment. This applied to 8% of the study population and included 93% of all treatment failures and 76% of all patients with advanced neoplastic progression. The model appeared robust in multiple sensitivity analyses and performed well in external validation (area under the curve, 0.84). CONCLUSIONS: We developed a prognostic model that identified patients with a BE length of 9 cm or longer and high-grade dysplasia/esophageal adenocarcinoma and those with poor squamous regeneration as high risk for a complex treatment course. The good performance in external validation suggests that it may be used in clinical management (Netherlands Trial Register: NL7039).

Impact of expert center endoscopic assessment of confirmed low grade dysplasia in Barrett's esophagus diagnosed in community hospitals.

BACKGROUND : The optimal management for patients with low grade dysplasia (LGD) in Barrett's esophagus (BE) is unclear. According to the Dutch national guideline, all patients with LGD with histological confirmation of the diagnosis by an expert pathologist (i. e. "confirmed LGD"), are referred for a dedicated re-staging endoscopy at an expert center. We aimed to assess the diagnostic value of re-staging endoscopy by an expert endoscopist for patients with confirmed LGD. METHODS : This retrospective cohort study included all patients with flat BE diagnosed in a community hospital who had confirmed LGD and were referred to one of the nine Barrett Expert Centers (BECs) in the Netherlands. The primary outcome was the proportion of patients with prevalent high grade dysplasia (HGD) or cancer during re-staging in a BEC. RESULTS : Of the 248 patients with confirmed LGD, re-staging in the BEC revealed HGD or cancer in 23 % (57/248). In 79 % (45/57), HGD or cancer in a newly detected visible lesion was diagnosed. Of the remaining patients, re-staging in the BEC showed a second diagnosis of confirmed LGD in 68 % (168/248), while the remaining 9 % (23/248) had nondysplastic BE. CONCLUSION : One quarter of patients with apparent flat BE with confirmed LGD diagnosed in a community hospital had prevalent HGD or cancer after re-staging at an expert center. This endorses the advice to refer patients with confirmed LGD, including in the absence of visible lesions, to an expert center for re-staging endoscopy.

Long-term outcomes after endoscopic treatment for Barrett's neoplasia with radiofrequency ablation ± endoscopic resection: results from the national Dutch database in a 10-year period.

OBJECTIVE: Radiofrequency ablation (RFA)±endoscopic resection (ER) is the preferred treatment for early neoplasia in Barrett's oesophagus (BE). We aimed to report short-term and long-term outcomes for all 1384 patients treated in the Netherlands (NL) from 2008 to 2018, with uniform treatment and follow-up (FU) in a centralised setting. DESIGN: Endoscopic therapy for early BE neoplasia in NL is centralised in nine expert centres with specifically trained endoscopists and pathologists that adhere to a joint protocol. Prospectively collected data are registered in a uniform database. Patients with low/high-grade dysplasia or low-risk cancer, were treated by ER of visible lesions followed by trimonthly RFA sessions of any residual BE until complete eradication of BE (CE-BE). Patients with ER alone were not included. RESULTS: After ER (62% of cases; 43% low-risk cancers) and median 1 circumferential and 2 focal RFA (p25-p75 0-1; 1-2) per patient, CE-BE was achieved in 94% (1270/1348). Adverse events occurred in 21% (268/1386), most commonly oesophageal stenosis (15%), all were managed endoscopically. A total of 1154 patients with CE-BE were analysed for long-term outcomes. During median 43 months (22-69) and 4 endoscopies (1-5), 38 patients developed dysplastic recurrence (3%, annual recurrence risk 1%), all were detected as endoscopically visible abnormalities. Random biopsies from a normal appearing cardia showed intestinal metaplasia (IM) in 14% and neoplasia in 0%. A finding of IM in the cardia was reproduced during further FU in only 33%, none progressed to neoplasia. Frequent FU visits in the first year of FU were not associated with recurrence risk. CONCLUSION: In a setting of centralised care, RFA±ER is effective for eradication of Barrett's related neoplasia and has remarkably low rates of dysplastic recurrence. Our data support more lenient FU intervals, with emphasis on careful endoscopic inspection. Random biopsies from neosquamous epithelium and cardia are of questionable value. NETHERLANDS TRIAL REGISTER NUMBER: NL7039.

Incidence and outcomes of poor healing and poor squamous regeneration after radiofrequency ablation therapy for early Barrett's neoplasia.

BACKGROUND: Endoscopic eradication therapy with radiofrequency ablation (RFA) is effective in most patients with Barrett's esophagus (BE). However, some patients experience poor healing and/or poor squamous regeneration. We evaluated incidence and treatment outcomes of poor healing and poor squamous regeneration. METHODS: We included all patients treated with RFA for early BE neoplasia from a nationwide Dutch registry based on a joint treatment protocol. Poor healing (active inflammatory changes or visible ulcerations ≥ 3 months post-RFA), poor squamous regeneration (< 50 % squamous regeneration), and treatment success (complete eradication of BE [CE-BE]) were evaluated. RESULTS: 1386 patients (median BE C2M5) underwent RFA with baseline low grade dysplasia (27 %), high grade dysplasia (30 %), or early cancer (43 %). In 134 patients with poor healing (10 %), additional time and acid suppression resulted in complete esophageal healing, and 67/134 (50 %) had normal squamous regeneration with 97 % CE-BE. Overall, 74 patients had poor squamous regeneration (5 %). Compared with patients with normal regeneration, patients with poor squamous regeneration had a higher risk for treatment failure (64 % vs. 2 %, relative risk [RR] 27 [95 % confidence interval [CI] 18-40]) and progression to advanced disease (15 % vs. < 1 %, RR 30 [95 %CI 12-81]). Higher body mass index, longer BE segment, reflux esophagitis, and < 50 % squamous regeneration after baseline endoscopic resection were independently associated with poor squamous regeneration in multivariable logistic regression. CONCLUSIONS: In half of the patients with poor healing, additional time and acid suppression led to normal squamous regeneration and excellent treatment outcomes. In patients with poor squamous regeneration, however, the risk for treatment failure and progression to advanced disease was significantly increased.

C-Met targeted fluorescence molecular endoscopy in Barrett's esophagus patients and identification of outcome parameters for phase-I studies.

Fluorescence molecular endoscopy (FME) is an emerging technique in the field of gastroenterology that holds potential to improve diagnosis and guide therapy, by serving as a 'red-flag' endoscopic imaging technique. Here, we investigated the safety, feasibility and optimal method of administration of EMI-137, targeting c-Met, during FME in Barrett's Esophagus (BE) and report several outcome parameters for early phase FME studies. Methods: FME was performed in 15 Barrett's neoplasia patients. EMI-137 was administered to three cohorts of five patients: 0.13 mg/kg intravenously (IV); 0.09 mg/kg IV or topically at a dose of 200 µg/cm BE (n=1) or 100 µg/cm BE (n=4). Fluorescence was visualized in vivo, quantified in vivo using multi-diameter single-fiber reflectance, single-fiber fluorescence (MDSFR/SFF) spectroscopy and correlated to histopathology and immunohistochemistry. EMI-137 localization was assessed using fluorescence microscopy. Results: FME using different IV and topical doses of EMI-137 appeared to be safe and correctly identified 16/18 lesions, although modest target-to-background ratios were observed (median range of 1.12-1.50). C-Met overexpression varied between lesions, while physiological expression in the stomach-type epithelium was observed. Microscopically, EMI-137 accumulated around the neoplastic cell membranes. We identified several outcome parameters important for the validation of EMI-137 for FME: 1) the optimal administration route; 2) optimal dose and safety; 3) in vivo FME contrast; 4) quantification of intrinsic fluorescence; 5) ex vivo correlation of fluorescence, histopathology and target expression; and 6) microscopic tracer distribution. Conclusions: C-Met targeted FME using EMI-137 may not be the ideal combination to improve BE surveillance endoscopies, however the identified outcome parameters may serve as a valuable guidance for designing and performing future early phase clinical FME studies, independent of which fluorescent tracer is investigated.

The Optimal Imaging Window for Dysplastic Colorectal Polyp Detection Using c-Met-Targeted Fluorescence Molecular Endoscopy.

Fluorescence molecular endoscopy (FME) is an emerging technique that has the potential to improve the 22% colorectal polyp detection miss-rate. We determined the optimal dose-to-imaging interval and safety of FME using EMI-137, a c-Met-targeted fluorescent peptide, in a population at high risk for colorectal cancer. Methods: We performed in vivo FME and quantification of fluorescence by multidiameter single-fiber reflectance/single-fiber fluorescence spectroscopy in 15 patients with a dysplastic colorectal adenoma. EMI-137 was intravenously administered (0.13 mg/kg) at a 1-, 2- or 3-h dose-to-imaging interval (n = 3 patients per cohort). Two cohorts were expanded to 6 patients on the basis of target-to-background ratios. Fluorescence was correlated to histopathology and c-Met expression. EMI-137 binding specificity was assessed by fluorescence microscopy and in vitro experiments. Results: FME using EMI-137 appeared to be safe and well tolerated. All dose-to-imaging intervals showed significantly higher fluorescence in the colorectal lesions than in surrounding tissue, with a target-to-background ratio of 1.53, 1.66, and 1.74 for the 1-, 2-, and 3-h cohorts, respectively, and a mean intrinsic fluorescence of 0.035 vs. 0.023 mm-1 (P < 0.0003), 0.034 vs. 0.021 mm-1 (P < 0.0001), and 0.033 vs. 0.019 mm-1 (P < 0.0001), respectively. Fluorescence correlated with histopathology on a macroscopic and microscopic level, with significant c-Met overexpression in dysplastic mucosa. In vitro, a dose-dependent specific binding was confirmed. Conclusion: FME using EMI-137 appeared to be safe and feasible within a 1- to 3-h dose-to-imaging interval. No clinically significant differences were observed among the cohorts, although a 1-h dose-to-imaging interval was preferred from a clinical perspective. Future studies will investigate EMI-137 for improved colorectal polyp detection during screening colonoscopies.

Completion rate of small bowel capsule endoscopy is higher after erythromycin compared to domperidone.

BACKGROUND: In up to 30 percent of small bowel capsule endoscopy procedures, the capsule does not reach the cecum within recording time. A prolonged gastric transit time has been recognized as a risk factor for incomplete capsule endoscopy. The aim of this study was to analyze if a single dose of orally administered erythromycin prior to capsule endoscopy results in a higher completion rate compared to orally administered domperidone. METHODS: Single centre, non-concurrent prospective cohort study, 649 capsule endoscopy procedures were included. Cecal completion rates, gastric and small bowel transit times and diagnostic yield were analyzed. RESULTS: 239 patients received erythromycin, 410 patients received domperidone. The cecal completion rate was 86% after erythromycin versus 80% after domperidone (p = 0.03). After excluding known risk factors for incomplete capsule endoscopy such as hospitalization and previous abdominal surgery, erythromycin still resulted in an increased completion rate (p = 0.04). Median gastric transit time was lower after erythromycin compared to domperidone (13 min versus 22 min, p < 0.001). Median small bowel transit times were similar in both groups (236 min versus 248 min, p = 0.21). CONCLUSIONS: In this study, the largest to date on this subject, the cecal completion rate was higher with erythromycin than with domperidone, but there was no difference in the diagnostic yield.

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

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

Diagnostic yield of small bowel capsule endoscopy depends on the small bowel transit time.

AIM: To investigate whether the small bowel transit time (SBTT) influences the diagnostic yield of capsule endoscopy (CE). METHODS: Six hundred and ninety-one consecutive CE procedures collected in a database were analyzed. SBTT and CE findings were recorded. A running mean for the SBTT was calculated and correlated to the diagnostic yield with a Spearman's correlation test. Subgroup analyses were performed for the various indications for the procedure. RESULTS: There was a positive correlation between the diagnostic yield and SBTT (Spearman's rho 0.58, P < 0.01). Positive correlations between diagnostic yield and SBTT were found for the indication obscure gastrointestinal bleeding (r = 0.54, P < 0.01), for polyposis and carcinoid combined (r = 0.56, P < 0.01) and for the other indications (r = 0.90, P <0.01), but not for suspected Crohn's disease (r = -0.40). CONCLUSION: The diagnostic yield in small bowel capsule endoscopy is positively correlated with the small bowel transit time. This is true for all indications except for suspected Crohn's disease.

Risk factors for incomplete small-bowel capsule endoscopy.

BACKGROUND: In 20% to 30% of capsule endoscopy (CE) procedures, the capsule does not reach the cecum within recording time, with incomplete imaging of the small bowel, which limits the value of CE. OBJECTIVE: To identify possible risk factors for incomplete small-bowel CE examinations. DESIGN: Data from consecutive CE procedures performed between September 2003 and August 2007 were analyzed. All patients had received the same preparation before the CE procedure, including the administration of a prokinetic agent. SETTING: Single-center retrospective study. PATIENTS: A total of 291 CE studies. MAIN OUTCOME MEASUREMENTS: Data were collected regarding patient demographics and potential risk factors. Cecal incompletion rates were calculated. Risk factors were analyzed by using a binary regression analysis. RESULTS: CE was incomplete in 55 cases (19%). The gastric transit time was significantly longer in patients with incomplete CE procedures than in patients with complete CE procedures (median 45 minutes vs 21 minutes, P= .005). Previous small-bowel surgery, hospitalization, moderate or poor bowel cleansing, and a gastric transit time longer than 45 minutes were identified as independent risk factors for incomplete CE procedures. LIMITATION: A retrospective study design. CONCLUSIONS: The identification of several risk factors for incomplete CE procedures allows for selectively targeting these factors in future procedures to reduce the risk of incomplete CE examinations.

Can we reduce capsule endoscopy reading times?

BACKGROUND: Analyzing small-bowel capsule endoscopy (CE) images is time consuming. OBJECTIVE: To determine the effect of reducing the number of images on reading time and interpretation of CE procedures. DESIGN: Two techniques aimed at reducing the number of images to be viewed were studied. The number of images was reduced by removing every second image (study A) or by the Quickview mode (study B). In both studies, one endoscopist viewed the images in the conventional way, whereas another endoscopist viewed the reduced number of images. SETTING: A single-center prospective study. PATIENTS: Two hundred CE procedures, 100 consecutive procedures for each study. MAIN OUTCOME MEASUREMENTS: Reading times for small-bowel images were recorded. Kappa (kappa) values were used to calculate interobserver agreement between viewing techniques. Diagnostic miss rates were calculated. RESULTS: Median procedure reading times were significantly reduced by viewing half the number of images (10.2 minutes) or using the Quickview technique (4.4 minutes) compared with conventional viewing (17.0 minutes). Interobserver agreement was excellent (kappa = 0.91) in study A and good (kappa = 0.74) in study B. The diagnostic miss rate was 2% when half the number of images were viewed and 8% when the Quickview technique was used. Agreement between both techniques and conventional viewing was best when the indication for the procedure was suspected inflammatory bowel disease. LIMITATION: Lack of a criterion standard. CONCLUSIONS: Techniques that reduce the number of images examined in CE are time saving but are associated with considerable diagnostic miss rates. Such techniques may only be considered if inflammatory bowel disease is suspected.