Bowel Mucosa Research Articles

Gastrointestinal: Small bowel hemangioma with unusual endoscopic findings and complicated with obscure gastrointestinal bleeding.

A 68-year-old woman was referred to our hospital for evaluation of severe anemia. Although she had an upper endoscopy and colonoscopy that failed to show the cause of her anemia, there was a small amount of blood in the terminal ileum, which suggested small bowel bleeding. In our hospital, video capsule endoscopy identified a spherically raised lesion in the jejunum, with central erosion of the surface mucosa, which was similar in morphology to a submucosal tumor (Fig. 1a). Balloon-assisted enteroscopy revealed a dark reddish, elevated lesion in the jejunum, the surface of which was extensively peeled off and thickly covered by blood clots (Fig. 1b). Malignant tumors such as angiosarcoma, gastrointestinal stromal tumor, and malignant lymphoma were suspected. A definitive preoperative diagnosis was difficult because of the unusual endoscopic findings. The patient underwent laparoscopic small bowel resection. The lesion was 17 mm in diameter (Fig. 2a). Histological findings revealed that the elevated lesion consisted of exposed vascular components, surrounded by normal small bowel mucosa, and numerous dilatated vessels without atypia were observed from the lamina propria to the muscularis propria. These findings were consistent with cavernous hemangioma (Fig. 2b,c). After surgery, the anemia improved within 6 months. Hemangiomas occur rarely in the small bowel. Thirteen cases of small bowel hemangiomas, observed preoperatively by enteroscopy, have been reported in adults. To the best of our knowledge, a submucosal tumor-like hemangioma with exposed vascular components is extremely rare and has been described in only one case. It was hypothesized that this uncommon morphology was formed by collapse of the tumor due to external stimuli such as small bowel peristalsis and food residue. This case highlights the unusual endoscopic appearance of small bowel hemangioma as a rare cause of obscure gastrointestinal bleeding.

The Usefulness of Tissue Calprotectin in Pediatric Crohn’s Disease—A Pilot Study

Background: Fecal calprotectin (FCP) is a highly sensitive biomarker of intestinal inflammation widely used in diagnostics and monitoring of inflammatory bowel disease (IBD). Immunohistochemical assessment of calprotectin in the bowel mucosa is not a diagnostic standard. Therefore, the aim of this study was to evaluate tissue calprotectin (TCP) as a potential marker providing added insight for pediatric patients with Crohn’s disease (CD). Methods: Fecal and tissue calprotectin were measured in children with CD. The values were correlated with disease activity and histopathological changes of the patients’ endoscopic biopsies. Disease activity was assessed using the Pediatric Crohn’s Disease Activity Index (PCDAI); fecal calprotectin (FCP) was measured with the ELISA test. Immunohistochemical (IHC) staining for calprotectin antigen was performed on the biopsy samples from six bowel segments, and the number of TCP cells was counted per high power field (HPF). Non-parametric statistical tests were used for data analysis. Results: Fifty-seven children with CD with a median age of 10.5 (1–17) years (yrs) were examined for fecal and tissue calprotectin. The patients’ median PCDAI score was 10 (0–63.5), while median FCP was 535 (30–600) μg/g. We observed a correlation between disease activity (PCDAI) and FCP, TCP in inflammatory lesions and in crypts. There was no association either between FCP and TCP or between TCP in epithelium and PCDAI. Conclusion: It seems that IHC detection of calprotectin in bowel mucosa to assess disease behavior may be useful. FCP is a gold-standard biomarker in the diagnosis, monitoring and prognosis of IBD, and its levels correlated well with clinical activity in our study group.

Role of endoscopy in the diagnosis of coeliac disease: a narrative review.

Coeliac disease (CD) is a common autoimmune disorder triggered by gluten consumption in genetically predisposed individuals. CD is characterised by chronic inflammation in the small bowel mucosa with an influx of lymphocytes, followed by crypt hyperplasia and villous atrophy. The gold standard test to diagnose CD is endoscopy with duodenal biopsies. However, variations in practice between endoscopists can lead to missed diagnoses. This review aims to discuss the role of endoscopy in the diagnosis of CD, highlighting the performance measures of endoscopy in CD and the advancement in endoscopic techniques for the optical diagnosis of villous atrophy. We searched PubMed and Google Scholar from their inception to December 2023 for relevant articles on the role of endoscopy in CD. Two authors reviewed these references, and relevant studies were included in the discussion section of this review. We provide an up-to-date assessment of the diagnostic accuracy of endoscopic markers of CD and the performance of enhanced endoscopic imaging to identify villous atrophy during endoscopy. We propose a set of benchmarks for endoscopy in CD and discuss the potential role of artificial intelligence (AI) in the endoscopic diagnosis of CD. Performing high-quality endoscopy and identifying strategies to reduce inter-endoscopist variations may reduce missed diagnoses. Adopting advanced endoscopic techniques and embracing new technologies such as AI could enhance diagnostic accuracy and improve patient care.

Rare Complications of Celiac Disease: Clinicopathologic Features

Celiac disease (CD) is an immune mediated disorder characterised by intolerance to glutens in certain grains like whet, barley, and rye. The exposure to gliadin protein component in the susceptible individuals leads to an inflammatory reaction damaging small bowel mucosa with progressive disappearance of intestinal villi. The damaged intestinal mucosa leads to malabsorption. The usual symptoms of celiac disease include diarrhea, steatorrhea, weight loss, fatigue, and abdominal pain. Diagnosis is based on clinical features, duodenal biopsy, elevated levels of anti-gliadin antibodies and response to gluten free diet. Contrary to common belief, celiac disease is a protein systemic disease rather than merely a pure digestive alteration. Celiac disease is closely associated with genes that code HLA -II antigens mainly of DQ2 and DQ8 classes, production of disease specific antibodies (i.e., endomysial antibodies), multiorgan involvement, comorbidity with other autoimmune diseases (shared autoimmunity), familial aggregation, and immune system dysregulation. The clinical presentation of celiac disease can be variable. In mild form, patients can be almost asymptomatic whereas in the most severe form, the patients are at increased risk of life-threatening complications. Celiac disease has a well-known association with other autoimmune diseases such as autoimmune liver diseases (autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis), diabetes mellitus, autoimmune thyroid diseases, skin diseases such as dermatitis herpetiformis, rheumatoid arthritis, systemic lupus erythematosus, Sjogren’s syndrome, psoriasis, sarcoidosis, immune thrombocytopenic purpura, and pancreatitis. In addition, celiac disease may be associated with rare but potentially serious complications such as, collagenous sprue, ulcerative jejunoileitis, refractory celiac disease (RCD), enteropathy associated T-cell lymphoma, small bowel adenocarcinoma (SBA), hyposplenism, and cavitating mesenteric lymph node syndrome (CMLNS). The present article describes clinicopathologic features of these rare but serious complications of celiac disease.

No-biopsy diagnostic approach to coeliac disease.

This brief review outlines contributions that Michael Marsh and others made to understanding the structure and function of the upper small bowel mucosa and the formation of abnormalities that occur in coeliac disease (CD). He introduced his classification of lesions 30 years ago that has been widely adopted. The development and use of serological tests to screen for and diagnose CD in children and adults without the need for a small bowel biopsy in a considerable proportion is also recognised and will gain traction.

Deciphering colorectal cancer genetics through multi-omic analysis of 100,204 cases and 154,587 controls of European and east Asian ancestries.

Colorectal cancer (CRC) is a leading cause of mortality worldwide. We conducted a genome-wide association study meta-analysis of 100,204 CRC cases and 154,587 controls of European and east Asian ancestry, identifying 205 independent risk associations, of which 50 were unreported. We performed integrative genomic, transcriptomic and methylomic analyses across large bowel mucosa and other tissues. Transcriptome- and methylome-wide association studies revealed an additional 53 risk associations. We identified 155 high-confidence effector genes functionally linked to CRC risk, many of which had no previously established role in CRC. These have multiple different functions and specifically indicate that variation in normal colorectal homeostasis, proliferation, cell adhesion, migration, immunity and microbial interactions determines CRC risk. Crosstissue analyses indicated that over a third of effector genes most probably act outside the colonic mucosa. Our findings provide insights into colorectal oncogenesis and highlight potential targets across tissues for new CRC treatment and chemoprevention strategies.

Safety and efficacy of capsule endoscopy for patients with newly diagnosed Crohn’s disease: A multicenter retrospective study

Crohn's disease (CD) is a chronic inflammatory disease that develops at a young age and frequently leads to intestinal resection. Capsule endoscopy (CE) can directly and non-invasively inspect the entire small bowel mucosa. We suspected that CE could be a good diagnostic tool for detecting CD in young patients. The aim of this study was to investigate the safety and efficacy of CE in patients with newly diagnosed CD and to evaluate the CE findings, especially in the upper small bowel of young patients. We retrospectively investigated 32 patients with newly diagnosed CD from 5 institutions. Patient characteristics, clinical course, and characteristics of CE findings were analyzed. The total small intestine observation rate was 93%, and the retention rate was 3% (1/32). No abnormality was identified by ileocolonoscopy in 46% (15/32), and transition of small bowel lesions (TSL) was found in 35% (12/34) of the patients. The frequency of longitudinal ulcers and cobblestones in the upper small intestine was significantly higher in younger patients (≤20 years). Moreover, positive findings in the upper small intestine were predominantly observed in younger patients (≤20 years). CE for patients with newly diagnosed CD was safe and useful, especially for the detection of upper small bowel lesions in young patients.

Novel lipid emulsion for total parenteral nutrition based on 18-carbon n–3 fatty acids elicits a superior immunometabolic phenotype in a murine model compared with standard lipid emulsions

While lipid emulsions in modern formulations for total parenteral nutrition (TPN) provide essential fatty acids and dense calories, they also promote inflammation and immunometabolic disruptions. We aimed to develop a novel lipid emulsion for TPN use with superior immunometabolic actions compared with available standard lipid emulsions. A novel lipid emulsion [Vegaven (VV)] containing 30% of 18-carbon n-3 fatty acids (α-linolenic acid and stearidonic acid) was developed for TPN (VV-TPN) and compared with TPN containing soybean oil-based lipid emulsion (IL-TPN) and fish-oil-based lipid emulsion (OV-TPN). In vivo studies were performed in instrumented male C57BL/6 mice subjected to 7-d TPN prior to analysis of cytokines, indices of whole-body and hepatic glucose metabolism, immune cells, lipid mediators, and mucosal bowel microbiome. IL-6 to IL-10 ratios were significantly lower in liver and skeletal muscle of VV-TPN mice when compared with IL-TPN or OV-TPN mice. VV-TPN and OV-TPN each increased hepatic insulin receptor abundance and resulted in similar HOMA-IR values, whereas only VV-TPN increased hepatic insulin receptor substrate 2 and maintained normal hepatic glycogen content, effects that were IL-10-dependent and mediated by glucokinase activation. The percentages of IFN-γ- and IL-17-expressing CD4+ T cells were increased in livers of VV-TPN mice, and liver macrophages exhibited primed phenotypes when compared with IL-TPN. This immunomodulation was associated with successful elimination of the microinvasive bacterium Akkermansia muciniphila from the bowel mucosa by VV-TPN as opposed to standard lipid emulsions. Assay of hepatic lipid mediators revealed a distinct profile with VV-TPN, including increases in 9(S)-hydroxy-octadecatrienoic acid. When co-administered with IL-TPN, hydroxy-octadecatrienoic acids mimicked the VV-TPN immunometabolic phenotype. We here report the unique anti-inflammatory, insulin-sensitizing, and immunity-enhancing properties of a newly developed lipid emulsion designed for TPN use based on 18-carbon n-3 fatty acids.

S1535 Common Variable Immunodeficiency-Like Enteropathy Associated With Rituximab B-Cell Depletion Therapy

Introduction: Rituximab (RTX), is a monoclonal antibody therapy directed at CD20 positive B lymphocytes, increasingly used in both malignant and autoimmune conditions. RTX therapy may result in hypogammaglobulinemia due to B cell depletion. The gastrointestinal side effects of the therapy are not well described. Here we report the clinical, endoscopic and histologic features of rituximab-associated enteropathy in a single center case series. Methods: Retrospective analysis of medical charts of patients with enteropathy presenting to a tertiary care university hospital between 2008 and 2021 were reviewed. Patients with enteropathy identified using diagnostic codes for: CVID, enteropathy, malabsorption, weight loss and diarrhea. Patients with rituximab use were further characterized. Clinical data, laboratory values, endoscopy and pathology reports were analyzed. Results: Ten patients with enteropathy associated with RTX therapy were identified without other competing etiology. Mean age was 64 years ± 17.4 and 5 (50%) patients were female. Lymphoma 8 (80%) was the most common indication for RTX therapy. Diarrhea and weight loss were the most common clinical presentation. The mean BMI on presentation was 18 kg/m2 with a mean total weight loss of 13.5 kg ± 8.9. Seven (70%) patients were defined as severely malnourished based on clinical criteria. Mean albumin was 3.3 g/dL (3.5-5) and pre-Albumin 16 g/dL (normal >21). Serum levels of IgA, IgM and IgG were below lower limit of normal. Endoscopic appearance of the duodenal mucosa was abnormal in 3/8 cases (37.5%) and 3/5 (60%) cases had decreased plasma cells in the lamina propria with villous atrophy (Figure 1). Seven patients (70%) had a pathologic diagnosis consistent with CVID enteropathy. All of the patients received IVIG therapy (100%) although only 2 had symptomatic improvement. Prednisone (n = 6), budesonide (n = 2), infliximab (n = 2) or vedolizumab (n = 1) did not lead to clinical improvement. Six (60%) required long term parenteral nutrition (PN). Conclusion: RTX is associated with a secondary CVID-like enteropathy with absent/decreased plasma cells in small bowel biopsies. Diarrhea with weight loss and severe malnutrition are common clinical features and patients often require parenteral nutrition. Treatment with IVIG and other immunosuppressive therapies rarely improves GI symptoms. RTX-associated enteropathy should be considered in patients presenting with diarrhea and/or weight loss and history of RTX use.Figure 1.: Small bowel mucosa showing a lack of lamina propria plasma cells (arrows).

S2075 Mixed Adeno-Neuroendocrine Carcinoma (MANEC) of Colon: Rare Differential Diagnosis for Iron Deficiency Anemia

Introduction: Colonic Mixed adenoneuroendocrine carcinoma (MANEC) is a rare but highly aggressive tumor. In English Literature only 10 cases or less have been reported of this neoplasm, with the prognosis still unfavorable. Mixed adenoneuroendocrine carcinomas, by definition, are comprised of at least 30% of both a neuroendocrine and an adenocarcinomatous component. Cases are typically diagnosed at advanced stages, and the age of presentation is younger than the average age of colorectal adenocarcinoma (∼60 years old). Metastasis can occur anywhere but usually seen in the liver, regional lymph nodes and rarely peritoneum. The tumor neuroendocrine markers and immunophenotype are essential for the diagnosis, for example chromogranin, synaptophysin, CDX-2, and CD56. Case Description/Methods: A 53-year-old women with a history of abdominal pain was diagnosed with NET via histopathology of the cecum. The patient was referred to us by her hematologist which he ordered CT/pelvis due to her new onset of iron deficiency anemia and CT scan showed irregular bowel wall thickening of proximal ascending colon with infiltration and nodularity of surrounding fat suspicious of colon neoplasm. The patient has diabetes mellitus and hypertension other than that she had no significant history of past illness. A colonoscopy and biopsy were performed that showed poorly differentiated carcinoma with ulceration in large bowel mucosa, morphologically, high grade poorly differentiated malignant neoplasm was noted with ulceration. Histopathology and Immunohistochemical studies show the tumor cells are positive for AE1/3, CK7, synptophysin, CDX-2, while negative for CK20, chromogranin, CD56. Ki-67 shows a high labeling index (−95%). The negative stain of tumor cells for MLH-1 and PMS2 can be associated with microsatellite instability related germ line mutation. The differential diagnosis includes poorly differentiated adenocarcinoma, mixed adenoneuroendocrine carcinoma and large cell endocrine carcinoma. A definitive classification depends on the total resection specimen (Figure 1). Discussion: Mixed adenoneuroendocrine carcinoma of the colon is a neoplasm consisting of 2 components coexisting simultaneously within a tumor. It is a very rare carcinoma that presents at a younger age than colorectal adenocarcinoma. Unfortunately, it is diagnosed usually at late stages when metastasis has occurred. If detected at early stages curative surgery can be the treatment. The prognosis Is poor due to late diagnosis and dual nature of the tumor.Figure 1.: Histology and Immunohistochemical studies.

Histopathological assessment of the microscopic activity in inflammatory bowel diseases: What are we looking for?

Advances in diagnostics of inflammatory bowel diseases (IBD) and improved treatment strategies allowed the establishment of new therapeutic endpoints. Currently, it is desirable not only to cease clinical symptoms, but mainly to achieve endoscopic remission, a macroscopic normalization of the bowel mucosa. However, up to one-third of IBD patients in remission exhibit persisting microscopic activity of the disease. The evidence suggests a better predictive value of histology for the development of clinical complications such as clinical relapse, surgical intervention, need for therapy escalation, or development of colorectal cancer. The proper assessment of microscopic inflammatory activity thus became an important part of the overall histopathological evaluation of colonic biopsies and many histopathological scoring indices have been established. Nonetheless, a majority of them have not been validated and no scoring index became a part of the routine bioptic practice. This review summarizes a predictive value of microscopic disease activity assessment for the subsequent clinical course of IBD, describes the most commonly used scoring indices for Crohn's disease and ulcerative colitis, and comments on current limitations and unresolved issues.

Effects of Dietary Supplementation with Glutamine on the Immunity and Intestinal Barrier Gene Expression in Broiler Chickens Infected with Salmonella Enteritidis.

Simple SummarySalmonella Enteritidis, a Gram-negative bacterium, is ingested into the gut of animals, especially young chicks. Glutamine (Gln), a nonessential amino acid, is an important energy source and active free radical-scavenging compound for enterocyte and lymphocyte cells. In this study, we found that Gln might alleviate the intestinal inflammatory response and increase the intestinal immune barrier function in broilers challenged with Salmonella Enteritidis. During the experimental period, supplementation with Gln improved growth performance, increased serum immunoglobulin concentrations and intestinal mucosa Bcl-2 mRNA expression levels, and decreased the lysozyme (LZM, only serum) and nitric oxide (NO) activities in serum and the intestinal mucosa, along with the intestinal mucosa barrier gene mRNA expression levels. These findings provide useful information regarding the intestinal immune barrier function of broilers.The effects of glutamine (Gln) on immunity and intestinal barrier gene expression levels in broilers challenged with Salmonella Enteritidis were evaluated. A total of 400 1-day-old broilers were randomly assigned to four groups, 10 repetition treatments per group with 10 broiler chickens for a 21-day feeding trial. The groups were the normal control group (CON, no infected group, fed with a basal diet); the S. Enteritidis-infected control group (SCC, infected with 2.0 × 104 CFU/mL of S. Enteritidis, fed a basal diet); and the Gln 1 and 2 groups, who were challenged with S. Enteritidis and fed a basal diet plus Gln at 0.5% and 1.0%, respectively. The results show that S. Enteritidis had adverse effects on the average daily feed intake, average daily gain, and the feed conversion ratio of infected broilers compared with those of CON broilers on d 7 (p < 0.05); decreased serum immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) concentrations, and intestinal mucosa Bcl-2 mRNA expression levels (p < 0.05); increased the Lysozyme (LZM, only serum), NO, inducible NO synthase (iNOS) (except at 4 d), and total nitric oxide synthase (TNOS) (except at 4 d) activities in serum and the intestinal mucosa; and increased intestinal mucosa polymeric immunoglobulin receptor (pIgR) (except at 21 d), Avian beta-defensin 5 (AvBD5), AvBD14, Bax, and Bak mRNA expression levels during the experimental period (p < 0.05). Supplementation with Gln improved growth performance; increased serum IgA, IgG, and IgM concentrations and intestinal mucosa Bcl-2 mRNA expression levels (p < 0.05); decreased the LZM (only serum), NO, iNOS (except at 4 d), and TNOS (except at 4 d) activities in serum and the intestinal mucosa; and decreased intestinal mucosa pIgR (except at 21 d), AvBD5, AvBD14, Bax, and Bak mRNA expression levels during the experimental period (p < 0.05). These results suggest that Gln might lessen the inflammatory reaction of the small intestine and enlarge the small bowel mucosa immune and barrier function in broiler chickens challenged with S. Enteritidis.

Obscure Gastrointestinal Bleeding and Capsule Endoscopy: A Win-Win Situation or Not?

Obscure gastrointestinal bleeding (OGIB) refers to bleeding of uncertain origin that persists or recurs after negative workup using any of the radiologic evaluation modalities. It can be divided into two types based on whether clinically evident bleeding is present, namely, obscure overt and obscure occult bleeding. As the visualization of the bowel mucosa is challenging, capsule endoscopy (CE) is the ideal go-to procedure as the process is wireless, ingestible, small, disposable, and, most importantly, non-invasive. This review article has compiled various studies to shed light on the guidelines for using CE, its structure and procedure, patient preferences, diagnostic yield, cost-effectiveness, and the future. The goal of this review is to show the influence of CE on OGIB on the aspects mentioned earlier.

Bacterial overgrowth and lactose intolerance: how to best assess.

To provide an up-to-date review on the clinical assessment of two important gastrointestinal problems with overlapping symptomatology but diverse cause and testing methods. Small intestinal bacterial overgrowth (SIBO) is characterized by the presence of excess bacteria in the small intestine associated with bloating, distention, gas, and diarrhea. Lactose intolerance is caused by lactase enzyme deficiency in the small bowel mucosa leading to lactose malabsorption and symptoms of bloating, gas, and diarrhea. SIBO is assessed by hydrogen/methane breath test using glucose as a substrate and/or small bowel aspirate and culture but these tests have shortcomings. Consequently, several new diagnostic techniques, including novel capsule technologies and other approaches are being evaluated. Lactose intolerance can be assessed by hydrogen/methane breath test using lactose as a substrate, or small bowel mucosal lactase assay, genetic testing and lactose tolerance test, although the efficacy and practicality of these diagnostic modalities are not equal. In clinical practice, gas, bloating, distention, pain, and diarrhea are common gastrointestinal symptoms that often remain unexplained when routine gastrointestinal endoscopy, imaging, and stool tests are negative. These patients should be evaluated for SIBO and/or food intolerances including lactose intolerance.

Mitochondrial Side Effects of Surgical Prophylactic Antibiotics Ceftriaxone and Rifaximin Lead to Bowel Mucosal Damage.

Despite their clinical effectiveness, a growing body of evidence has shown that many classes of antibiotics lead to mitochondrial dysfunction. Ceftriaxone and Rifaximin are first choice perioperative antibiotics in gastrointestinal surgery targeting fundamental processes of intestinal bacteria; however, may also have negative consequences for the host cells. In this study, we investigated their direct effect on mitochondrial functions in vitro, together with their impact on ileum, colon and liver tissue. Additionally, their impact on the gastrointestinal microbiome was studied in vivo, in a rat model. Rifaximin significantly impaired the oxidative phosphorylation capacity (OxPhos) and leak respiration in the ileal mucosa, in line with increased oxidative tissue damage and histological changes following treatment. Ceftriaxone prophylaxis led to similar changes in the colon mucosa. The composition and diversity of bacterial communities differed extensively in response to antibiotic pre-treatment. However, the relative abundances of the toxin producing species were not increased. We have confirmed the harmful effects of prophylactic doses of Rifaximin and Ceftriaxone on the intestinal mucosa and that these effects were related to the mitochondrial dysfunction. These experiments raise awareness of mitochondrial side effects of these antibiotics that may be of clinical importance when evaluating their adverse effects on bowel mucosa.

Visual gaze patterns in trainee endoscopists – a novel assessment tool

Background Colonoscopy proficiency is significantly influenced by skills achieved during training. Although assessment scores exist, they do not evaluate the impact of visual search strategies and their use is time and labour intensive. Eye-tracking has shown significant differences in visual gaze patterns (VGPs) between expert endoscopists with varying polyp detection rates, so may provide a means of automated assessment and guidance for trainees. This study aimed to assess the feasibility of eye-tracking as a novel assessment method for trainee endoscopists. Methods Eye-tracking glasses were used to record 26 colonoscopies from 12 endoscopy trainees who were assessed with directly observed procedural scores (DOPS), devised by the Joint Advisory Group (JAG) on GI endoscopy, and a visual analogue score of overall competence. A ‘total weighted procedure score’ (TWPS) was calculated from 1 to 20. Primary outcomes of fixation duration (FixD) and fixation frequency (FixF) were analysed according to areas of interest (AOIs) with the bowel surface and lumen represented by three concentric rings. Correlation was assessed using Pearson’s coefficient. Significance was set at p<.050. Results Trainees displayed a significant positive correlation between TWPS and FixD (R = 0.943, p<.0001) and FixF (R = 0.936, p<.0001) in the anatomical bowel mucosa peripheries. Conversely, they had significant negative correlations between TWPS and the anatomical bowel lumen (FixD: R= −0.546, p=.004; FixF: R= −0.568, p=.002). Conclusions Higher objective performance scores were associated with VGPs focussing on bowel mucosa. This is consistent with prior analysis showing peripheral VGPs correspond with higher polyp detection rates. Analysis of VGPs, therefore, has potential for training and assessment in colonoscopy.

Automated detection of celiac disease using Machine Learning Algorithms

Celiac disease is a disorder of the immune system that mainly affects the small intestine but can also affect the skeletal system. The diagnosis relies on histological assessment of duodenal biopsies acquired by upper digestive endoscopy. Immunological tests involve collecting a blood sample to detect if the antibodies have been produced in the body. Endoscopy is invasive and histology is time-consuming. In recent years there have been various algorithms that use artificial intelligence (AI) and neural convolutions (CNN, Convolutional Neural Network) to process images from capsule endoscopy, a non-invasive endoscopy approach, that provides magnified, high qualitative images of the small bowel mucosa, to quickly establish a diagnosis. The proposed innovative approach do not use complex learning algorithms, instead it find some artefacts in the endoscopies using kernels and use classified machine learning algorithms. Each used artefacts have a psychical meaning: atrophies of the mucosa with a visible submucosal vascular pattern; the presence of cracks (depressions) that have an appearance similar to that of dry land; reduction or complete loss of folds in the duodenum; the presence of a submerged appearance at the Kerckring folds and a low number of villi. The results obtained for video capsule endoscopy images processing reveal an accuracy of 94.1% and F1 score of 94%, which is competitive with other complex algorithms. The main goal of the present research was to demonstrate that computer-aided diagnosis of celiac disease is possible even without the use of very complex algorithms, which require expensive hardware and a lot of processing time. The use of the proposed automated images processing acquired noninvasively by capsule endoscopy would be assistive in detecting the subtle presence of villous atrophy not evident by visual inspection. It may also be useful to assess the degree of improvement of celiac. Patients on a gluten-free diet, the main treatment method for stopping the autoimmune process and improving the state of the small intestinal villi. The novelty of the work is that the algorithm uses two modified filters to properly analyse the intestine wall texture. It is proved that using the right filters, the proper diagnostic can be obtained by image processing, without the use of a complicated machine learning algorithm.

DOP57 Development and validation of a convolutional neural network for the automatic detection of enteric ulcers and erosions in capsule endoscopy: A multicentric study

Abstract Background Capsule endoscopy (CE) is the gold-standard for the evaluation of the enteric mucosa in patients with suspected or known inflammatory bowel disease, particularly Crohn’s disease. Ulcers and erosions of the small bowel are common findings and their identification in CE is paramount for an accurate disease stratification. Several artificial intelligence (AI) algorithms have been developed to aid endoscopists to detect lesions in different endoscopic modalities. With this project we intend to develop and test an AI algorithm for the automatic identification of ulcers and erosions in the small bowel mucosa. Methods A total of 2565 CE exams from two different centers (1483 from São João University Hospital and 1082 from ManopH Gastroenterology Clinic) were used to develop the Convolutional Neural Network (CNN). 55320 frames of the enteric mucosa were obtained, 18396 containing enteric ulcers and erosions, and 36924 containing normal mucosa. 90% of the frames were used to develop the training dataset and 10% were used to test the network. The patients included on the training dataset were excluded from the testing dataset. This patient split brings the technology performance closer to that of a real-life setting. The output provided by the CNN was compared to the classification provided by a consensus of experts. Results Our model was able to automatically detect ulcers and erosions in the enteric mucosa with an accuracy of 93.2%, sensitivity of 90.4% and a specificity of 93.9%. The mean processing time for the validation dataset was 29 seconds (approximately 306 frames/second). An example of the output obtained after the network application can be seen in Figure 1. Conclusion The authors developed a CNN for the automatic identification of enteric ulcers and erosions in CE videos and tested it in AI naïve patients. This represents an evolution in the technology readiness level into a real-life clinical setting, that will surely improve the diagnostic yield of CE exams, which will ultimately translate into better patient care.

Automated detection of ulcers and erosions in capsule endoscopy images using a convolutional neural network

Capsule endoscopy (CE) is an important tool in the management of patients with known or suspected inflammatory bowel disease. Ulcers and erosions of the enteric mucosa are prevalent findings in these patients. They frequently occur together, and their identification in CE is crucial for an accurate evaluation of disease severity. Nevertheless, reviewing CE images is a time-consuming task, and the risk of overlooking lesions is significant.Over the last decade, artificial intelligence (AI) has emerged as a means for overcoming these pitfalls. Of all AI methods, convolutional neural networks (CNN), due to their complex multilayer architecture present the best results in medical image analysis, particularly capsule endoscopy. Therefore, we aimed to develop a CNN for the automatic identification of ulcers and erosions in the small bowel mucosa. A total of 1483 CE exams (PillCam SB3®) performed at a single center between 2015 and 2020 were analysed. From these exams, a total of 6130 frames of the enteric mucosa were obtained, 4233 containing enteric ulcers and erosions, and the remaining containing normal mucosa or other findings. Ulcers and erosions were stratified according to Saurin's classification for bleeding potential: P1E-erosions with intermediate bleeding risk; P1U-ulcers with intermediate bleeding risk; P2U-ulcers with high bleeding risk. For automatic identification of these lesions, these images were inserted into a CNN model with transfer learning. The pool of images was divided for constitution of training and validation datasets, comprising 80% and 20% of the total number of images, respectively. The output provided by the CNN was compared to the classification provided by a consensus of specialists. After optimizing the neural architecture of the algorithm, our model was able to automatically detect and distinguish ulcers and erosions (any bleeding potential) in the small intestine mucosa with an accuracy of 95.6%, sensitivity of 90.8%, and a specificity of 97.1%. We believe that our study lays the foundation for the development and application of effective AI tools to CE. These techniques should improve diagnostic accuracy and reading efficiency. Schematic representation of the workflow and summary of the results.

Non-invasive laparoscopic detection of small tumors of the digestive tract using inductive sensors of proximity

The precise location of gastric and colorectal tumors is of paramount importance for the oncological surgeon as it dictates the limits of resection and the extent of lymphadenectomy. However, this task proves sometimes to be very challenging, especially in the laparoscopic setting when the tumors are small, have a soft texture, and do not invade the serosa. In this view, our research team has developed a new instrument adapted to minimally-invasive surgery, and manipulated solely by the operating surgeon which has the potential to locate precisely tumors of the digestive tract. It consists of an inductive proximity sensor and an electronic block encapsulated into an autoclavable stainless-steel cage that works in tandem with an endoscopic hemostatic clip whose structure was modified to increase detectability. By scanning the serosal side of the colon or stomach, the instrument is capable to accurately pinpoint the location of the clip placed previously during diagnostic endoscopy on the normal bowel mucosa, adjacent to the tumor. In the current in-vivo experiments performed on large animals, the modified clips were transported without difficulties to the point of interest and attached to the mucosa of the bowel. Using a laparoscopic approach, the detection rate of this system reached 65% when the sensor scanned the bowel at a speed of 0.3 cm/s, and applying slight pressure on the serosa. This value increased to 95% when the sensor was guided directly on the point of clip attachment. The detection rate dropped sharply when the scanning speed exceeded 1 cm/s and when the sensor-clip distance exceeded the cut-off value of 3 mm. In conclusion, the proposed detection system demonstrated its potential to offer a swift and convenient solution for the digestive laparoscopic surgeons, however its detection range still needs to be improved to render it useful for the clinical setting.