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Precise optical diagnosis of colorectal polyps could improve the cost-effectiveness of colonoscopy and reduce polypectomy-related complications. However, it is difficult for community-based non-experts to obtain sufficient diagnostic performance. Artificial intelligence-based systems have been developed to analyze endoscopic images; they identify neoplasms with high accuracy and low interobserver variation. We performed a multi-center study to determine the diagnostic accuracy of EndoBRAIN, an artificial intelligence-based system that analyzes cell nuclei, crypt structure, and microvessels in endoscopic images, in identification of colon neoplasms. The EndoBRAIN system was initially trained using 69,142 endocytoscopic images, taken at 520-fold magnification, from patients with colorectal polyps who underwent endoscopy at 5 academic centers in Japan from October 2017 through March 2018. We performed a retrospective comparative analysis of the diagnostic performance of EndoBRAIN vs that of 30 endoscopists (20 trainees and 10 experts); the endoscopists assessed images from 100 cases produced via white-light microscopy, endocytoscopy with methylene blue staining, and endocytoscopy with narrow-band imaging. EndoBRAIN was used to assess endocytoscopic, but not white-light, images. The primary outcome was the accuracy of EndoBrain in distinguishing neoplasms from non-neoplasms, compared with that of endoscopists, using findings from pathology analysis as the reference standard. In analysis of stained endocytoscopic images, EndoBRAIN identified colon lesions with 96.9% sensitivity (95% CI, 95.8%–97.8%), 100% specificity (95% CI, 99.6%–100%), 98% accuracy (95% CI, 97.3%–98.6%), a 100% positive-predictive value (95% CI, 99.8%–100%), and a 94.6% negative-predictive (95% CI, 92.7%–96.1%); these values were all significantly greater than those of the endoscopy trainees and experts. In analysis of narrow-band images, EndoBRAIN distinguished neoplastic from non-neoplastic lesions with 96.9% sensitivity (95% CI, 95.8–97.8), 94.3% specificity (95% CI, 92.3–95.9), 96.0% accuracy (95% CI, 95.1–96.8), a 96.9% positive-predictive value, (95% CI, 95.8–97.8), and a 94.3% negative-predictive value (95% CI, 92.3–95.9); these values were all significantly higher than those of the endoscopy trainees, sensitivity and negative-predictive value were significantly higher but the other values are comparable to those of the experts. EndoBRAIN accurately differentiated neoplastic from non-neoplastic lesions in stained endocytoscopic images and endocytoscopic narrow-band images, when pathology findings were used as the standard. This technology has been authorized for clinical use by the Japanese regulatory agency and should be used in endoscopic evaluation of small polyps more widespread clinical settings. UMIN clinical trial no: UMIN000028843. [ABSTRACT FROM AUTHOR]

Background & Aims In patients with persistent symptoms after Heller myotomy (HM), treatment options include repeat HM, pneumatic dilation, or peroral endoscopic myotomy (POEM). We evaluated the efficacy and safety of POEM in patients with achalasia with prior HM vs without prior HM. Methods We conducted a retrospective cohort study of 180 patients with achalasia who underwent POEM at 13 tertiary centers worldwide, from December 2009 through September 2015. Patients were divided into 2 groups: those with prior HM (HM group, exposure; n = 90) and those without prior HM (non-HM group; n = 90). Clinical response was defined by a decrease in Eckardt scores to 3 or less. Adverse events were graded according to criteria set by the American Society for Gastrointestinal Endoscopy. Technical success, clinical success, and rates of adverse events were compared between groups. Patients were followed up for a median of 8.5 months. Results POEM was technically successful in 98% of patients in the HM group and in 100% of patients in the non-HM group ( P = .49). A significantly lower proportion of patients in the HM group had a clinical response to POEM (81%) than in the non-HM group (94%; P = .01). There were no significant differences in rates of adverse events between the groups (8% in the HM group vs 13% in the non-HM group; P = .23). Symptomatic reflux and reflux esophagitis after POEM were comparable between groups. Conclusions POEM is safe and effective for patients with achalasia who were not treated successfully by prior HM. Although the rate of clinical success in patients with prior HM is lower than in those without prior HM, the safety profile of POEM is comparable between groups. [ABSTRACT FROM AUTHOR]

It is now possible to perform microscopic imaging of living cells from both normal mucosa and malignant tissue in the gastrointestinal tract. Endocytoscopy is a catheter-type contact endoscope that has more than 1000-fold magnifying power and can pass through the working channel of the straight-view endoscope. In esophageal cells, the nucleus, cell body, and even the nucleolus were clearly distinguished with high-resolution images comparable with those of conventional cytology. This novel technology has the potential to provide histologic diagnoses during endoscopic examinations, similar to those obtained currently by conventional histology techniques. [Copyright &y& Elsevier]