Seven cases of upper gastrointestinal bleeding after cold biopsy

Convolutional neural network-based system for endocytoscopic diagnosis of early gastric cancer

Background

Endocytoscopy (ECS) aids early gastric cancer (EGC) diagnosis by visualization of cells. However, it is difficult for non-experts to accurately diagnose EGC using ECS. In this study, we developed and evaluated a convolutional neural network (CNN)-based system for ECS-aided EGC diagnosis.

Methods

We constructed a CNN based on a residual neural network with a training dataset comprising 906 images from 61 EGC cases and 717 images from 65 noncancerous gastric mucosa (NGM) cases. To evaluate diagnostic ability, we used an independent test dataset comprising 313 images from 39 EGC cases and 235 images from 33 NGM cases. The test dataset was further evaluated by three endoscopists, and their findings were compared with CNN-based results.

Results

The trained CNN required 7.0 s to analyze the test dataset. The area under the curve of the total ECS images was 0.93. The CNN produced 18 false positives from 7 NGM lesions and 74 false negatives from 28 EGC lesions. In the per-image analysis, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 83.2%, 76.4%, 92.3%, 93.0%, and 74.6%, respectively, with the CNN and 76.8%, 73.4%, 81.3%, 83.9%, and 69.6%, respectively, for the endoscopist-derived values. The CNN-based findings had significantly higher specificity than the findings determined by all endoscopists. In the per-lesion analysis, the accuracy, sensitivity, specificity, PPV, and NPV of the CNN-based findings were 86.1%, 82.1%, 90.9%, 91.4%, and 81.1%, respectively, and those of the results calculated by the endoscopists were 82.4%, 79.5%, 85.9%, 86.9%, and 78.0%, respectively.

Conclusions

Compared with three endoscopists, our CNN for ECS demonstrated higher specificity for EGC diagnosis. Using the CNN in ECS-based EGC diagnosis may improve the diagnostic performance of endoscopists.

The development and clinical application of microscopic endoscopy for in vivo optical biopsies: Endocytoscopy and confocal laser endomicroscopy

Endoscopies are crucial for detecting and diagnosing diseases in gastroenterology, pulmonology, urology, and other fields. To accurately diagnose diseases, sample biopsies are indispensable and are currently considered the gold standard. However, random 4-quadrant biopsies have sampling errors and time delays. To provide intraoperative real-time microscopic images of suspicious lesions, microscopic endoscopy for in vivo optical biopsy has been developed, including endocytoscopy and confocal laser endomicroscopy. This article reviews recent advances in technology and clinical applications, as well as their shortcomings and future directions.

Histologic Findings in Mucosa and Muscularis Propria Biopsied During Peroral Endoscopic Myotomy in Patients With Achalasia

Background

Peroral endoscopic myotomy (POEM) has been increasingly used to treat achalasia. Previous studies have reported high frequency of muscular eosinophilic infiltration in achalasia. Esophageal mucosal changes in achalasia have only been studied in esophagectomy specimens. Cardia mucosal changes in achalasia have not been reported previously. We aimed to further characterize the esophageal, gastric cardia, and muscularis propria changes in achalasia.

Methods

This was a pilot study. Patients with clinically and radiographically confirmed achalasia who underwent POEM were enrolled in the study. Mucosal biopsies were taken 1 cm proximal and 1 cm distal to the gastroesophageal junction, and muscularis propria biopsies were taken from the mid esophagus. Tissues were submitted for histological evaluation.

Results

Eighteen patients (10 male and eight female, mean age: 60.7 (standard deviation (SD): 13) years) were enrolled in this pilot study. Nine patients had type II achalasia, two type III, one type I, five esophageal gastric outlet obstruction, and one unspecific type achalasia. The mean duration of symptoms prior to POEM was 79 (range 1 - 480) months. All patients had a dilated esophagus on examination, but no endoscopic evidence of Barrett's esophagus. Esophageal, gastric cardia, and muscular biopsies were performed in 17, 13, and 17 patients, respectively. Basal hyperplasia, spongiosis, ballooning, and parakeratosis were seen in 92.3%, 100%, 100%, and 76.5% of cases, respectively. Intraepithelial lymphocytosis was seen in 70.5% of cases, and active esophagitis was seen in 23.5% of case. Six (35.3%) cases had few intraepithelial eosinophils, but none of them had > 15 eosinophils per high power field. Histologic findings in gastric cardia mucosa included carditis (69.2%), H. pylori gastritis (7.6%), and reactive gastropathy (15.4%). One case (7.6%) showed low-grade dysplasia arising from intestinal metaplasia in the cardia. Absence of ganglion cells in the muscular biopsies was noted in 88.2% of cases, and the remaining two showed rare residual ganglion cells with ganglionitis in one case (5.8%). Muscular atrophy and interstitial fibrosis were observed in 52.9% and 82.3% of the cases, respectively. Two cases (11.7%) had eosinophilic inflammation in the muscularis propria and one of them was accompanied by lymphocytic inflammation.

Conclusions

Muscular biopsies in our study revealed loss of ganglion cells, supporting the view that achalasia is a primary esophageal disease with ganglion cell depletion. Squamous mucosa in achalasia showed changes mimicking reflux and lymphocytic esophagitis. Cardia mucosa in achalasia patients often were inflamed and uncommonly showed intestinal metaplasia and glandular dysplasia.

Economic value of narrow-band imaging versus white light endoscopy for the diagnosis and surveillance of Barrett's esophagus: Cost-consequence model

Barrett’s esophagus (BE) is an abnormality arising from gastroesophageal reflux disease that can progressively evolve into a sequence of dysplasia and adenocarcinoma. Progression of Barrett’s esophagus into dysplasia is monitored with endoscopic surveillance. The current surveillance standard requests random biopsies plus targeted biopsies of suspicious lesions under white-light endoscopy, known as the Seattle protocol. Recently, published evidence has shown that narrow-band imaging (NBI) can guide targeted biopsies to identify dysplasia and reduce the need for random biopsies. We aimed to assess the health economic implications of adopting NBI-guided targeted biopsy vs. the Seattle protocol from a National Health Service England perspective. A decision tree model was developed to undertake a cost-consequence analysis. The model estimated total costs (i.e. staff and overheads; histopathology; adverse events; capital equipment) and clinical implications of monitoring a cohort of patients with known/suspected BE, on an annual basis. In the simulation, BE patients (N = 161,657 at Year 1; estimated annual increase: +20%) entered the model every year and underwent esophageal endoscopy. After 7 years, the adoption of NBI with targeted biopsies resulted in cost reduction of £458.0 mln vs. HD-WLE with random biopsies (overall costs: £1,966.2 mln and £2,424.2 mln, respectively). The incremental investment on capital equipment to upgrade hospitals with NBI (+£68.3 mln) was offset by savings due to the reduction of histological examinations (-£505.2 mln). Reduction of biopsies also determined savings for avoided adverse events (-£21.1 mln). In the base-case analysis, the two techniques had the same accuracy (number of correctly identified cases: 1.934 mln), but NBI was safer than HD-WLE. Budget impact analysis and cost-effectiveness analyses confirmed the findings of the cost-consequence analysis. In conclusion, NBI-guided targeted biopsies was a cost-saving strategy for NHS England, compared to current practice for detection of dysplasia in patients with BE, whilst maintaining at least comparable health outcomes for patients.

Value of routine duodenal mucosal biopsies in the evaluation of anemia in a large Australian referral centre

Background and Aim

Small bowel mucosal biopsies (SBBx) are routinely performed to investigate unexplained anemia; however, previous studies have demonstrated a low yield in diagnosing celiac disease. Our aim was to determine the yield of routine SBBx in a large cohort of patients who underwent gastroscopy for the investigation of anemia.

Methods

Data from consecutive patients who underwent gastroscopy for the investigation of anemia in a tertiary hospital, from January 2008–December 2011, were prospectively collected. Measured outcomes were the prevalence of celiac disease, the yield of duodenal biopsies, and the correlation between celiac serology and diagnosis.

Results

Over 4 years, 987 patients (385 M:602 F; 48.27 ± 15.89 years) underwent endoscopy for anemia, of which 534 (54.1%) had proven iron deficiency anemia (IDA). Abnormal SBBx consistent with celiac disease were found in 2% (22/987), with a higher prevalence in females (3.2%, n = 19 vs 0.8%, n = 3 in males) and in those with IDA (3.6%, n = 19 vs 0.7%, n = 3 in non‐IDA). Macroscopic endoscopic abnormalities were present in 86% (19/22) of patients with celiac disease. Of the 178 patients who had celiac serology, tissue transglutaminase antibody had the highest sensitivity (80%) and specificity (99%). Combined serology had a sensitivity of 85.7%.

Conclusion

Only 2% of patients with unexplained anemia had abnormal SBBx consistent with celiac disease and even fewer patients in non‐IDA. Given the availability and high sensitivity of celiac serology and macroscopic changes on endoscopy, SBBx should not be routine during endoscopy but should be limited to those with positive celiac serology, abnormal endoscopic appearance, or females with IDA.