A highly accurate method for monitoring histological recovery in patients with celiac disease on a gluten-free diet using an endoscopic approach that avoids the need for biopsy: a double-center study

Advances in Imaging of Inflammation, Fibrosis, and Cancer in the Gastrointestinal Tract

Gastrointestinal disease is prevalent and broad, manifesting itself in a variety of ways, including inflammation, fibrosis, infection, and cancer. However, historically, diagnostic technologies have exhibited limitations, especially with regard to diagnostic uncertainty. Despite development of newly emerging technologies such as optoacoustic imaging, many recent advancements have focused on improving upon pre-existing modalities such as ultrasound, computed tomography, magnetic resonance imaging, and endoscopy. These advancements include utilization of machine learning models, biomarkers, new technological applications such as diffusion weighted imaging, and new techniques such as transrectal ultrasound. This review discusses assessment of disease processes using imaging strategies for the detection and monitoring of inflammation, fibrosis, and cancer in the context of gastrointestinal disease. Specifically, we include ulcerative colitis, Crohn's disease, diverticulitis, celiac disease, graft vs. host disease, intestinal fibrosis, colorectal stricture, gastric cancer, and colorectal cancer. We address some of the most recent and promising advancements for improvement of gastrointestinal imaging, including unique discussions of such advancements with regard to imaging of fibrosis and differentiation between similar disease processes.

A Call for Research on the Prognostic Role of Follow-Up Histology in Celiac Disease: A Systematic Review

Background: Convincing evidence is lacking on the benefit of follow-up biopsy in celiac disease. Regardless, achieving mucosal recovery (MR) has remained a desirable goal of therapy. We aimed to conduct a systematic review to determine whether MR is a protective factor and persisting villous atrophy (PVA) has negative consequences on long-term outcomes of celiac disease.

Methods: Seven databases were searched for articles discussing celiac patients subjected to a gluten-free diet who had a follow-up biopsy, and clinical and laboratory characteristics were reported by follow-up histology (MR vs. PVA). Outcomes included clinical symptoms, mortality, malignant tumors, nutritional parameters, and metabolic bone disease. Comparative and descriptive studies were included. Since data proved to be ineligible for meta-analysis, the evidence was synthesized in a systematic review.

Results: Altogether, 31 studies were eligible for systematic review. Persisting symptoms were more frequently associated with PVA than with MR, although a lot of symptom-free patients had PVA and a lot of symptomatic patients achieved MR. PVA might be a risk factor of lymphomas, but mortality and the overall rate of malignant tumors seemed independent of follow-up histology. Patients with PVA tended to develop metabolic bone disease more often, although fracture risk remained similar in the groups except in hip fractures of which PVA was a risk factor. Reports on nutritional markers are only anecdotal.

Conclusions: The limited evidence calls for high-quality prospective cohort studies to be arranged to clarify the exact role of follow-up histology in celiac disease.

Statement on Best Practices in the Use of Pathology as a Diagnostic Tool for Celiac Disease: A Guide for Clinicians and Pathologists

Small intestinal biopsy interpretation has been the cornerstone for the diagnosis of celiac disease for over 50 years. Despite the existence of sensitive and specific serological tests, duodenal mucosal biopsies continue to be obtained in the vast majority of patients in whom a diagnosis of celiac disease is being considered. The accurate evaluation of these biopsies requires coordination and information sharing between the gastroenterologist, laboratory, and pathologist in order to optimize tissue sampling, preparation and interpretation. This document, a collaboration between the Rodger C. Haggitt Gastrointestinal Pathology Society and the North American Association for the Study of Celiac Disease, is intended to provide clinicians and pathologists with a summary of best practices in the use of endoscopy and biopsy for patients with suspected celiac disease. The authors present a comprehensive and critical appraisal of the literature with respect to the topics of endoscopic findings, best methods for the obtaining biopsies, completing the pathology form and pathologic assessment, including evaluating intraepithelial lymphocytes and villous architecture. A discussion of conditions with overlapping pathologic findings in duodenal mucosal biopsies is presented. In order to provide additional guidance for challenging situations, the authors include an appendix containing practical suggestions. This review may be utilized in interdisciplinary discussions to optimize care for patients with possible celiac disease.

Identifying and improving adherence to the gluten-free diet in people with coeliac disease

Coeliac disease (CD) is an autoimmune gastrointestinal disorder whereby the ingestion of gluten, a storage protein found in wheat, barley and rye, causes damage to intestinal mucosa with resultant malabsorption, increased risk of anaemia and osteoporosis. Worldwide estimates suggest 1% of the population have CD. With no cure, the only treatment is a gluten-free diet (GFD). Adhering to a GFD can be very challenging; it requires knowledge, motivation and modified behaviours. Assessing adherence to a GFD is methodologically challenging. This review aims to provide an overview of the literature reporting adherence to a GFD in people with CD and the methodological challenges encountered. From six studies it has been reported that rates of adherence to a GFD range between 45 and 90% in patients of different ethnicities with CD. GF dietary adherence can be influenced by age at diagnosis, coexisting depression, symptoms on ingestion of gluten, nutrition counselling, knowledge of GF foods, understanding of food labels, cost and availability of GF foods, receiving GF foods on prescription and membership of a coeliac society. To date only five intervention studies in adults with CD have been undertaken to improve GF dietary adherence. These have included dietary and psychological counselling, and the use of online training programmes, apps, text messages and telephonic clinics. Future interventions should include people of all ethnicities, consider patient convenience and the cost-effectiveness for the healthcare environment.

A comprehensive review on the utility of capsule endoscopy in coeliac disease: From computational analysis to the bedside

Small bowel capsule endoscopy (SBCE) can identify macroscopic changes of coeliac disease and assess the extent of disease in the small bowel beyond the duodenum. SBCE has a good sensitivity for the detection of coeliac disease in comparison to histology owing to several ideal features such as a high magnification. It also plays a useful role in detecting complications in patients with refractory coeliac disease. Several studies have been carried out on transforming images obtained from small bowel capsule endoscopy to enable the automated detection of features related to coeliac disease. This review discusses the current roles played by small bowel capsule endoscopy in coeliac disease. It identifies future potential roles of this technique and describes in great detail the role of computational analysis in the detection of coeliac disease and how it can be adapted to current available technology.

Capsule endoscopy for patients with coeliac disease

Coeliac disease is an autoimmune mediated condition in response to gluten. A combination of innate and adaptive immune responses results in villous shortening in the small bowel (SB) that can be morphologically picked up on capsule endoscopy. It is the only imaging modality that can provide mucosal views of the entire SB, while histology is generally limited to the proximal SB. Radiological modalities are not designed to pick up changes in villous morphology. Areas covered: In this review, we provide a comprehensive analysis on the justified use of small bowel capsule endoscopy (SBCE) in the assessment of patients with coeliac disease; compare SBCE to histology, serology, and symptomatology; and provide an overview on automated quantitative analysis for the detection of coeliac disease. We also provide insight into future work on SBCE in relation to coeliac disease. Expert commentary: SBCE has opened up new avenues for the diagnosis and monitoring of patients with coeliac disease. However, larger studies with new and established coeliac disease patients and with greater emphasis on morphological features on SBCE are required to better define the role of SBCE in the setting of coeliac disease.

Outcome measures in coeliac disease trials: the Tampere recommendations

OBJECTIVE

A gluten-free diet is the only treatment option of coeliac disease, but recently an increasing number of trials have begun to explore alternative treatment strategies. We aimed to review the literature on coeliac disease therapeutic trials and issue recommendations for outcome measures.

DESIGN

Based on a literature review of 10 062 references, we (17 researchers and 2 patient representatives from 10 countries) reviewed the use and suitability of both clinical and non-clinical outcome measures. We then made expert-based recommendations for use of these outcomes in coeliac disease trials and identified areas where research is needed.

RESULTS

We comment on the use of histology, serology, clinical outcome assessment (including patient-reported outcomes), quality of life and immunological tools including gluten immunogenic peptides for trials in coeliac disease.

CONCLUSION

Careful evaluation and reporting of outcome measures will increase transparency and comparability of coeliac disease therapeutic trials, and will benefit patients, healthcare and the pharmaceutical industry.

Disease activity indices in coeliac disease: systematic review and recommendations for clinical trials

OBJECTIVE

Although several pharmacological agents have emerged as potential adjunctive therapies to a gluten-free diet for coeliac disease, there is currently no widely accepted measure of disease activity used in clinical trials. We conducted a systematic review of coeliac disease activity indices to evaluate their operating properties and potential as outcome measures in registration trials.

DESIGN

MEDLINE, EMBASE and the Cochrane central library were searched from 1966 to 2015 for eligible studies in adult and/or paediatric patients with coeliac disease that included coeliac disease activity markers in their outcome measures. The operating characteristics of histological indices, patient-reported outcomes (PROs) and endoscopic indices were evaluated for content and construct validity, reliability, responsiveness and feasibility using guidelines proposed by the US Food and Drug Administration (FDA).

RESULTS

Of 19 123 citations, 286 studies were eligible, including 24 randomised-controlled trials. Three of five PROs identified met most key evaluative criteria but only the Celiac Disease Symptom Diary (CDSD) and the Celiac Disease Patient-Reported Outcome (CeD PRO) have been approved by the FDA. All histological and endoscopic scores identified lacked content validity. Quantitative morphometric histological analysis had better reliability and responsiveness compared with qualitative scales. Endoscopic indices were infrequently used, and only one index demonstrated responsiveness to effective therapy.

CONCLUSIONS

Current best evidence suggests that the CDSD and the CeD PRO are appropriate for use in the definition of primary end points in coeliac disease registration trials. Morphometric histology should be included as a key secondary or co-primary end point. Further work is needed to optimise end point configuration to inform efficient drug development.

Younger age at diagnosis predisposes to mucosal recovery in celiac disease on a gluten-free diet: A meta-analysis

Background and aims

Persistent intestinal damage is associated with higher complication rates in celiac disease. We aimed to assess the potential modifiers of mucosal recovery.

Materials and methods

We screened databases (PubMed, Embase, Cochrane Trials, and Web of Science) for papers on celiac disease. Papers discussing (1) celiac patients (2) follow-up biopsy and (3) mucosal recovery after commencement of a gluten-free diet were included. The primary outcome was to produce a comprehensive analysis of complete mucosal recovery (i.e., Marsh 0 on follow-up). We compared children’s recovery ratios to those of adults. Patients following a strict gluten-free dietary regimen were included in a subgroup. Summary point estimates, 95% confidence intervals (CIs), and 95% predictive intervals (PIs) were calculated. Heterogeneity was tested with I²-statistic. The PROSPERO registration number is CRD42016053482.

Results

The overall complete mucosal recovery ratio, calculated from 37 observational studies, was 0.36 (CI: 0.28–0.44, PI: -0.12–0.84; I²: 98.4%, p<0.01). Children showed higher complete mucosal recovery ratio than adults (p<0.01): 0.65 (CI: 0.44–0.85, PI: -0.10–1.39; I²: 96.5%, p<0.01) as opposed to 0.24 (CI: 0.15–0.33, PI: -0.19–1.08; I²: 96.3%, p<0.01). In the strict dietary adherence subgroup, complete mucosal recovery ratio was 0.47 (CI: 0.24–0.70, PI: -0.47–1.41; I²: 98.8%, p<0.001). On meta-regression, diagnostic villous atrophy (Marsh 3) ratio (-8.97, p<0.01) and male ratio (+6.04, p<0.01) proved to be a significant determinant of complete mucosal recovery, unlike duration of gluten-free diet (+0.01, p = 0.62). The correlation between complete mucosal recovery ratio and age on diagnosis is of borderline significance (-0.03, p = 0.05).

Conclusions

There is considerable heterogeneity across studies concerning complete mucosal recovery ratios achieved by a gluten-free diet in celiac disease. Several celiac patients fail to achieve complete mucosal recovery even if a strict dietary regimen is followed. Younger age on diagnosis, less severe initial histologic damage and male gender predispose for achieving mucosal recovery.

Tests for Serum Transglutaminase and Endomysial Antibodies Do Not Detect Most Patients With Celiac Disease and Persistent Villous Atrophy on Gluten-free Diets: a Meta-analysis

BACKGROUND & AIMS

Tests to measure serum endomysial antibodies (EMA) and antibodies to tissue transglutaminase (tTG) were developed to screen for celiac disease in patients consuming gluten. However, they are commonly used to monitor patients on a gluten-free diet (GFD). We conducted a meta-analysis to assess the sensitivity and specificity of tTG IgA and EMA IgA assays in identifying patients with celiac disease who have persistent villous atrophy despite a GFD.

METHODS

We searched PUBMED, EMBASE, BIOSIS, SCOPUS, clinicaltrials.gov, Science Citation Index, and Cochrane Library databases through November 2016. Inclusion criteria were studies of subjects with biopsy-confirmed celiac disease, follow-up biopsies, and measurement of serum antibodies on a GFD, biopsy performed on subjects regardless of symptoms, or antibody test results. Our analysis excluded subjects with refractory celiac disease, undergoing gluten challenge, or consuming a prescribed oats-containing GFD. Tests were considered to have positive or negative findings based on manufacturer cut-off values. Villous atrophy was defined as a Marsh 3 lesion or villous height:crypt depth ratio below 3.0. We constructed forest plots to determine the sensitivity and specificity of detection for individual studies. For the meta-analysis, a bivariate random effects model was used to jointly model sensitivity and specificity.

RESULTS

Our search identified 5408 unique citations. Following review of abstracts, 442 articles were reviewed in detail. Only 26 studies (6 of tTG assays, 15 of EMA assays, and 5 of tTG and EMA assays) met our inclusion criteria. The most common reason studies were excluded from our analysis was inability to cross-tabulate histologic and serologic findings. The serum assays identified patients with persistent villous atrophy with high levels of specificity: 0.83 for the tTG IgA assay (95% CI, 0.79-0.87) and 0.91 for the EMA IgA assay (95% CI, 0.87-0.94). However, they detected villous atrophy with low levels of sensitivity: 0.50 for the tTG IgA assay (95% CI, 0.41-0.60) and 0.45 for the EMA IgA assay (95% CI, 0.34-0.57). The tests had similar levels of performance in pediatric and adult patients.

CONCLUSIONS

In a meta-analysis of patients with biopsy-confirmed celiac disease undergoing follow-up biopsy on a GFD, we found that tests for serum tTG IgA and EMA IgA levels had low sensitivity (below 50%) in detection of persistent villous atrophy. We need more-accurate non-invasive markers of mucosal damage in children and adults with celiac disease who are following a GFD.

Small bowel villous atrophy: celiac disease and beyond

Small bowel villous atrophy can represent a diagnostic challenge for gastroenterologists and pathologists. In Western countries small bowel atrophy and mild non-atrophic alterations are frequently caused by celiac disease. However, other pathology can mimic celiac disease microscopically, widening the differential diagnosis. The several novelties on this topic and the introduction of the device-assisted enteroscopy in the diagnostic flowchart make an update of the literature necessary. Areas covered: In this review, a description of the different clinical scenarios when facing with small bowel mucosal damage, particularly small bowel atrophy, is described. The published literature on this subject has been summarized and reviewed. Expert commentary: When an intestinal mucosal alteration is histologically demonstrated, the pathology report forms part of a more complex workup including serological data, clinical presentation and clinical history. A multidisciplinary team, including pathologists and enteroscopy-devoted endoscopists, is frequently required to manage patients with small bowel alterations, especially in cases of severe malabsorption syndrome.

Computer-aided texture analysis combined with experts' knowledge: Improving endoscopic celiac disease diagnosis

AIM: To further improve the endoscopic detection of intestinal mucosa alterations due to celiac disease (CD).

METHODS: We assessed a hybrid approach based on the integration of expert knowledge into the computer-based classification pipeline. A total of 2835 endoscopic images from the duodenum were recorded in 290 children using the modified immersion technique (MIT). These children underwent routine upper endoscopy for suspected CD or non-celiac upper abdominal symptoms between August 2008 and December 2014. Blinded to the clinical data and biopsy results, three medical experts visually classified each image as normal mucosa (Marsh-0) or villous atrophy (Marsh-3). The experts’ decisions were further integrated into state-of-the-art texture recognition systems. Using the biopsy results as the reference standard, the classification accuracies of this hybrid approach were compared to the experts’ diagnoses in 27 different settings.

RESULTS: Compared to the experts’ diagnoses, in 24 of 27 classification settings (consisting of three imaging modalities, three endoscopists and three classification approaches), the best overall classification accuracies were obtained with the new hybrid approach. In 17 of 24 classification settings, the improvements achieved with the hybrid approach were statistically significant (P < 0.05). Using the hybrid approach classification accuracies between 94% and 100% were obtained. Whereas the improvements are only moderate in the case of the most experienced expert, the results of the less experienced expert could be improved significantly in 17 out of 18 classification settings. Furthermore, the lowest classification accuracy, based on the combination of one database and one specific expert, could be improved from 80% to 95% (P < 0.001).

CONCLUSION: The overall classification performance of medical experts, especially less experienced experts, can be boosted significantly by integrating expert knowledge into computer-aided diagnosis systems.

High definition endoscopy with or without I-Scan increases the detection of celiac disease during routine endoscopy

BACKGROUND AND AIMS

Celiac disease remains underdiagnosed at endoscopy. We aimed to assess the utility of I-Scan (virtual chromo-endoscopy) to improve sensitivity of endoscopy to detect markers of villous atrophy in this condition.

METHODS

Patients from 2 UK hospitals were studied in 3 groups. Group 1: standard high definition, white light endoscopy (WLE); Group 2: WLE plus I-Scan; Group 3: non-high definition control group. The presence of endoscopic markers was recorded. At least 4 duodenal biopsies were taken from all patients. Serology was performed concurrently and observations were compared with histology.

RESULTS

758 patients (62% female, mean age 52) were recruited (Group 1: 230; Group 2: 228; Group 3: 300). 135 (17.8%) new diagnoses of coeliac disease were made (21 Group 1; 24 Group 2; 89 Group 3). The sensitivity for detection of endoscopic markers of villous atrophy was significantly higher in both Group 1 (85.7%, p=0.0004) and Group 2 (75%, p=0.005) compared to non-high definition controls (41.6%). There was no significant difference between high definition only and I-Scan groups (p=0.47). In non-high definition endoscopy a missed diagnosis was associated with lesser degrees of villous atrophy (p=0.019) and low tTG titre (p=0.007).

CONCLUSIONS

High definition endoscopy with or without I-Scan increases the detection of celiac disease during routine endoscopy.

Survey on computer aided decision support for diagnosis of celiac disease

Celiac disease (CD) is a complex autoimmune disorder in genetically predisposed individuals of all age groups triggered by the ingestion of food containing gluten. A reliable diagnosis is of high interest in view of embarking on a strict gluten-free diet, which is the CD treatment modality of first choice. The gold standard for diagnosis of CD is currently based on a histological confirmation of serology, using biopsies performed during upper endoscopy. Computer aided decision support is an emerging option in medicine and endoscopy in particular. Such systems could potentially save costs and manpower while simultaneously increasing the safety of the procedure. Research focused on computer-assisted systems in the context of automated diagnosis of CD has started in 2008. Since then, over 40 publications on the topic have appeared. In this context, data from classical flexible endoscopy as well as wireless capsule endoscopy (WCE) and confocal laser endomicrosopy (CLE) has been used. In this survey paper, we try to give a comprehensive overview of the research focused on computer-assisted diagnosis of CD.

•

The state-of-the-art research in automated diagnosis of celiac disease is presented.

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A systematic review of methods and techniques used in this field is given.

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Specific issues and challenges in the field are identified and discussed.

Endoscopic tools for the diagnosis and evaluation of celiac disease

Celiac disease (CD) is an autoimmune disease of the small bowel induced by ingestion of wheat, rye and barley. Current guidelines indicate histological analysis on at least four duodenal biopsies as the only way to diagnose CD. These indications are based on the conception of the inability of standard endoscopy to make diagnosis of CD and/or to drive biopsy sampling. Over the last years, technology development of endoscopic devices has greatly ameliorated the accuracy of macroscopic evaluation of duodenal villous pattern, increasing the diagnostic power of endoscopy of CD. The aim of this paper is to review the new endoscopic tools and procedures proved to be useful in the diagnosis of CD, such as chromoendoscopy, Fujinon Intelligent Chromo Endoscopy, Narrow Band Imaging, Optical Coherence Tomography, Water-Immersion Technique, confocal laser endomicroscopy, high-resolution magnification endoscopy, capsule endoscopy and I-Scan technology.

Evaluation of different distortion correction methods and interpolation techniques for an automated classification of celiac disease

Due to the optics used in endoscopes, a typical degradation observed in endoscopic images are barrel-type distortions. In this work we investigate the impact of methods used to correct such distortions in images on the classification accuracy in the context of automated celiac disease classification. For this purpose we compare various different distortion correction methods and apply them to endoscopic images, which are subsequently classified. Since the interpolation used in such methods is also assumed to have an influence on the resulting classification accuracies, we also investigate different interpolation methods and their impact on the classification performance. In order to be able to make solid statements about the benefit of distortion correction we use various different feature extraction methods used to obtain features for the classification. Our experiments show that it is not possible to make a clear statement about the usefulness of distortion correction methods in the context of an automated diagnosis of celiac disease. This is mainly due to the fact that an eventual benefit of distortion correction highly depends on the feature extraction method used for the classification.

Scale invariant texture descriptors for classifying celiac disease

Scale invariant texture recognition methods are applied for the computer assisted diagnosis of celiac disease. In particular, emphasis is given to techniques enhancing the scale invariance of multi-scale and multi-orientation wavelet transforms and methods based on fractal analysis. After fine-tuning to specific properties of our celiac disease imagery database, which consists of endoscopic images of the duodenum, some scale invariant (and often even viewpoint invariant) methods provide classification results improving the current state of the art. However, not each of the investigated scale invariant methods is applicable successfully to our dataset. Therefore, the scale invariance of the employed approaches is explicitly assessed and it is found that many of the analyzed methods are not as scale invariant as they theoretically should be. Results imply that scale invariance is not a key-feature required for successful classification of our celiac disease dataset.

Difficult diagnosis of celiac disease: diagnostic accuracy and utility of chromo-zoom endoscopy

BACKGROUND

Chromo-zoom endoscopy has been demonstrated to be valuable in assessing the degree of intestinal villous atrophy in patients with suspected celiac disease.

OBJECTIVE

To evaluate the diagnostic accuracy of chromo-zoom endoscopy in patients with difficult diagnosis because of nonconcordant test results and/or the confounding of a gluten-free diet initiated before an appropriate diagnosis of celiac disease and to compare the findings to a recent reference standard, the in vitro gliadin challenge test.

DESIGN

Prospective, case-control study.

SETTING

Tertiary-care referral hospital.

PATIENTS

Patients without celiac disease (negative control group, n = 9), patients with celiac disease (positive control group, n = 41), and patients with difficult diagnosis (n = 27).

INTERVENTION

Chromo-endoscopy with indigo carmine and endoscopic zoom-magnification were performed. Duodenal fragments were collected for the in vitro gliadin challenge test. The area under the receiver operating characteristic curve (ROC) was used for statistical analyses on accuracy.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy of chromo-zoom endoscopy for detection of mucosal abnormalities in patients with difficult diagnosis.

RESULTS

Chromo-zoom endoscopy had a high accuracy for celiac disease diagnosis in analyses on negative controls and positive controls (area under roc = 0.99). In the difficult diagnosis group, the accuracy of chromo-zoom endoscopy was lower (area under roc = 0.83), but it increased after exclusion of patients with celiac disease on gluten-free diet (area under roc = 0.88).

LIMITATIONS

There was a 4% failure rate in the ability to cultivate biopsies. Also, the study was done at an academic medical center.

CONCLUSION

Chromo-zoom endoscopy has high accuracy for cases of difficult diagnosis of celiac disease but only in untreated patients with celiac disease.

Enteroscopy: Advances in diagnostic imaging

Routine endoscopic imaging of the small bowel is performed with videoendoscopic white light technology. However, currently there are many new methods that improve our visual acuity when evaluating the small bowel mucosa. These methods are collectively called "advanced endoscopic imaging". These imaging methods include high-definition white light endoscopy, standard and dye-less or "virtual" chromoendoscopy, magnification endoscopy and confocal laser endomicroscopy. Regardless of the method used to image the small bowel the endosocopist needs to pay attention to detail and focus on three essential aspects: a) the shape of the lesion, b) the superficial mucosal detail (i.e. "pit pattern") and c) the submucosal vascular pattern. This review describes advances in the endoscopic imaging methods to study the small bowel.

Automated Marsh-like classification of celiac disease in children using local texture operators

Automated classification of duodenal texture patches with histological ground truth in case of pediatric celiac disease is proposed. The classical focus of classification in this context is a two-class problem: mucosa affected by celiac disease and unaffected duodenal tissue. We extend this focus and apply classification according to a modified Marsh scheme into four classes. In addition to other techniques used previously for classification of endoscopic imagery, we apply local binary pattern (LBP) operators and propose two new operator types, one of which adapts to the different properties of wavelet transform subbands. The achieved results are promising in that operators based on LBP turn out to achieve better results compared to many other texture classification techniques as used in earlier work. Specifically, the proposed wavelet-based LBP scheme achieved the best overall accuracy of all feature extraction techniques considered in the two-class case and was among the best in the four-class scheme. Results also show that a classification into four classes is feasible in principle however when compared to the two-class case we note that there is still room for improvement due to various reasons discussed.

Water-immersion sigmoidoscopy to treat acute GI bleeding in the perioperative period after surgical colorectal anastomosis

BACKGROUND

The occurrence of lower acute GI bleeding in the early perioperative period after colorectal anastomosis represents a life-threatening condition. The early treatment includes surgery or endoscopy, the latter being subject to complications associated with air insufflation and associated perforation.

OBJECTIVE

To study the feasibility, efficacy, and safety of early perioperative water-immersion endoscopy to treat the source of bleeding in patients having undergone colorectal anastomosis.

DESIGN

To prospectively study patients with active lower GI bleeding early after colorectal anastomosis and subject them to therapeutic water-immersion endoscopy instead of surgery.

SETTING

University referral center for digestive surgery and endoscopy.

PATIENTS

This study involved 2 patients presenting with active lower GI bleeding within 4 days after colorectal surgery.

INTERVENTION

Instead of air insufflation during endoscopy, an underwater investigation was performed in each patient after colonic water immersion.

MAIN OUTCOME MEASUREMENTS

Efficacy of therapeutic endoscopy.

RESULTS

Water-immersion endoscopy in each case allowed us to identify the location of the anastomosis and the source of active bleeding. It allowed us to safely place clips on the active vessels and stop the bleeding.

LIMITATIONS

Number of patients included, no comparison between conventional endoscopy and water-immersion endoscopy.

CONCLUSION

Diagnostic as well as therapeutic water-immersion colonoscopy is safe in patients presenting with active lower GI bleeding in the early perioperative period after colorectal anastomosis.

Endocytoscopy for the detection of microstructural features in adult patients with celiac sprue: a prospective, blinded endocytoscopy-conventional histology correlation study

BACKGROUND

Endocytoscopy (EC) is a novel technique that allows magnified live inspection of the intestinal mucosa.

OBJECTIVE

To evaluate EC for the detection of key pathological findings in patients with celiac sprue.

DESIGN

A total of 166 EC recordings were prospectively acquired. Matched videos, images, and biopsy specimens were obtained by duodenal argon beamer labeling of the respective sites.

SETTING

Academic tertiary referral center.

PATIENTS

Forty patients (mean age 51.5 years, 70% women) with established (n = 32) or suspected (n = 8) celiac disease (CD).

INTERVENTIONS

A validated scoring system (Marsh classification) was used to assess disease activity. EC criteria were independently evaluated by 2 gastroenterologists and 1 pathologist.

MAIN OUTCOME MEASUREMENTS

The primary endpoint was to examine EC correlation with conventional CD histology.

RESULTS

Of 166 duodenal biopsy sites, 23% were classified as Marsh III (moderate to severe), 10% as Marsh I (mild), and 67% as Marsh 0 (normal). Using the 450x magnification, we found that identification of crypts was diagnostic for celiac pathology. Four criteria were significant predictors of Marsh III pathology when adjusted by multivariate analysis: low number of villi per visual field (<3; odds ratio [OR] 9.1; 95% CI, 1.3-62.0), confluence of villi (OR 37.1; 95% CI, 1.3-1021.2), irregular epithelial lining (OR 10.9; 95% CI, 2.5-46.7), and inability to delineate loop capillaries (OR 14.9; 95% CI, 3.3-67.0). None was a good predictor of Marsh I pathology.

LIMITATIONS

Single-center experience. No prospective validation of the criteria in an independent patient population.

CONCLUSIONS

EC at 450x magnification accurately identifies mucosal histopathology of advanced CD, but not early morphological changes.

Water-immersion technique during standard upper endoscopy may be useful to drive the biopsy sampling of duodenal mucosa in children with celiac disease

OBJECTIVE

To evaluate the accuracy of the water-immersion technique during upper endoscopy in recognizing the duodenal villous pattern in a series of children who were undergoing endoscopy to obtain duodenal biopsy for histological analysis.

MATERIALS AND METHODS

The water-immersion technique was performed in 19 children. Endoscopic findings were compared with histology. Results were assessed on per biopsy analysis and per patient analysis, taking into account the worst endoscopic finding in each patient and correlating it with the worst histological diagnosis.

RESULTS

Per biopsy analysis: A total of 57 biopsy specimens were obtained and assessed. The endoscopic duodenal investigation correctly identified 53 areas (93%), which corresponded to histology, giving it an accuracy rate of 93%. Per patient analysis: The worst histology of the duodenal bulb was predicted by endoscopy in 18 of the 19 enrolled patients (95%), whereas the worst histopathological lesion of the second portion of the duodenum was recognized in 100% of cases. On the whole, therefore, the endoscopist suggested a diagnosis of celiac disease in 11 patients, with both positive and negative predictive values of 100%.

CONCLUSIONS

The water-immersion technique during upper endoscopy is highly accurate in recognizing the duodenal villous pattern in subjects who need a duodenal investigation. Our findings encourage a cost-saving and patient-retaining approach to the diagnosis of celiac disease by driving biopsy and reducing the number of duodenal samplings.

Automated classification of duodenal imagery in celiac disease using evolved Fourier feature vectors

Feature extraction techniques based on selection of highly discriminant Fourier filters have been developed for an automated classification of magnifying endoscope images with respect to pit patterns of colon lesions. These are applied to duodenal imagery for diagnosis of celiac disease. Features are extracted from the Fourier domain by selecting the most discriminant features using an evolutionary algorithm. Subsequent classification is performed with various standard algorithms (KNN, SVM, Bayes classifier) and combination of several Fourier filters and classifiers which is called multiclassifier. The obtained results are promising, due to a high specificity for the detection of mucosal damage typical of untreated celiac disease.

The water immersion technique is easy to learn for routine use during EGD for duodenal villous evaluation: a single-center 2-year experience

GOALS

We investigated the learning parameters of the immersion technique for the assessment of marked villous atrophy (MVA), during routine esophagogastroduodenoscopy (EGD).

BACKGROUND

The immersion technique offers a proven possibility of enhancing the sensitivity of endoscopy in detecting duodenal villous atrophy patterns.

STUDY

Nine endoscopists with at least 2 years of experience, who had previously been trained to perform the immersion technique, searched for duodenal villi during routine EGD. In a 2-year study, duodenal villi were evaluated underwater duodenoscopy in 432 patients from whom duodenal biopsies had been, for various reasons, obtained. The endoscopic findings were compared with the histology. The learning parameters of the water immersion technique and the accuracy in detecting subjects with MVA were observed.

RESULTS

A total of 28 (6.5%) patients with MVA were identified during endoscopy by the trained endoscopists. All these patients were diagnosed as being celiac patients. The sensitivity, specificity, and accuracy (positive and negative predictive values) of the immersion technique in detecting MVA patterns, irrespective of the endoscopist who performed the examination, were always 100%.

CONCLUSIONS

The underwater evaluation of the duodenum can be efficiently and regularly performed during routine EGD by endoscopists with 2 years of experience, after a specific, brief training period. This procedure is simple, feasible, and can accurately detect MVA patterns.

Emerging technologies in upper gastrointestinal endoscopy and celiac disease

Despite advances in our knowledge of celiac disease, the most current and authoritative recommendations conclude that diagnosis requires at least four biopsy specimens to be taken from the duodenal area. These recommendations are based on the perception that classic endoscopic markers are not adequate to target biopsy sampling to sites of villous damage in the duodenum. In the past few years, newly developed procedures and technologies have improved endoscopic recognition of the duodenum. These advances make possible the real-time recognition of the duodenal villous pattern during an upper endoscopy procedure, and thereby have the potential to optimize diagnostic accuracy. It is, therefore, reasonable to hypothesize that upper endoscopy might have a more incisive role in the diagnosis of celiac disease than merely providing a means of obtaining biopsy specimens for histological analysis. This Review highlights the new technologies in the field of upper endoscopy that could be helpful for the diagnosis of celiac disease, including the water-immersion technique, chromoendoscopy, high-resolution magnification endoscopy, optimal band imaging, optical coherence tomography and confocal endomicroscopy.

[Small intestine capsule endoscopy in the diagnostics of coeliac disease]

Coeliac disease is an autoimmune enteropathy precipitated by the gluten content of cereals. It had for long been considered a childhood condition as clinical symptoms manifested when gluten was introduced into the diet. The introduction of specific serological markers changed our understanding of the epidemiology and semiology of the syndrome. The main difficulty of the diagnostics arises from the fact that over 50% of patients with gluten-sensitive enteropathy show atypical symptoms, while coeliac-disease patients with extra-gastrointestinal manifestations show no gastrointestinal symptoms at all. Diagnostics of coeliac disease is currently based on the detection of specific antibodies and the histological assessment of the duodenum. Macroscopic signs of villous atrophy (reduction in the number or loss of Kerking's folds, vascular pattern visible through the mucosa, "mosaic or micronodular" pattern, "scalloped" folds) are clearly visible in untreated patients. Capsule endoscopy, contrary to conventional endoscopic approaches, enables non-invasive, pain-free investigation of the entire small intestine. Duodenal mucosa is visualised at an 8:1 magnification during the investigation, enabling the assessment of villous atrophy by an experienced investigator. Based on preliminary experience, standard upper tract endoscopy and capsule endoscopy appear to exhibit equal levels of sensitivity and specificity for coeliac disease. The advantage of CE versus upper tract endoscopy lies in the complete assessibility of the small intestine, thus also enabling the assessment of the spread and severity of the disease. The disadvantage associated with the approach is the lack of histological biopsy samples. CE is recommendable as a first line approach for patients with proven coeliac disease when alarm conditions appear.

Optimal band imaging system: a new tool for enhancing the duodenal villous pattern in celiac disease

BACKGROUND

The optimal band imaging (OBI) system is a new technology that can select better spectral images decomposed from ordinary endoscopic images. This technology, first introduced as "FUJI Intelligent Color Enhancement," enhances the contrast of the mucosal surface without the use of dyes.

OBJECTIVE

This study aimed to evaluate the potential of OBI for predicting the duodenal villous morphologic characteristics in patients with suspected celiac disease.

DESIGN

This study was designed as an open, prospective, single-center trial. Duodenoscopy was performed with a high-resolution magnification view, in association with OBI spectral processing. Duodenal villous patterns were evaluated and classified as normal, partially atrophic, or markedly atrophic. The endoscopic results were then compared with the histologic diagnosis.

SETTING

Endoscopy unit at the A. Gemelli University Hospital of Rome, Italy.

PATIENTS

Sixty-one patients undergoing upper endoscopy for clinical history of malabsorption or serologic suspicion for celiac disease were included in the study.

RESULTS

From OBI sets using red, green, and blue wavelength combinations that ranged from 400 to 580 nm, the endoscopist was able to find marked villous atrophy of the duodenum in 16 subjects, partial villous atrophy in 9 subjects, and normal villi in the remaining 36 subjects. The sensitivity, specificity, and positive and negative predictive values of the OBI-based duodenoscopy were 100% accurate in the evaluation of villous patterns.

CONCLUSIONS

High-resolution magnification endoscopy with OBI allows clear visualization of the duodenal villous pattern. The OBI system may play a potential role in optimizing the diagnostic accuracy of endoscopy in celiac disease.