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BACKGROUND AND AIM Recently, the BLI Adenoma Serrated International Classification (BASIC) system was developed by European experts to differentiate colorectal polyps. Our aim was to validate the BASIC classification system among the US-based endoscopy experts. METHODS Participants utilized a web-based interactive learning system where the group was asked to characterize polyps using the BASIC criteria: polyp surface (presence of mucus, regular/irregular and [pseudo]depressed), pit appearance (featureless, round/non-round with/without dark spots; homogeneous/heterogeneous distribution with/without focal loss), and vessels (present/absent, lacy, peri-cryptal, irregular). The final testing consisted of reviewing BLI images/videos to determine whether the criteria accurately predicted the histology results. Confidence in adenoma identification (rated "1" to "5") and agreement in polyp (adenoma vs non-adenoma) identification and characterization per BASIC criteria were derived. Strength of interobserver agreement with kappa (k) value was reported for adenoma identification. RESULTS Ten endoscopy experts from the United States identified conventional adenoma (vs non-adenoma) with 94.4% accuracy, 95.0% sensitivity, 93.8% specificity, 93.8% positive predictive value, and 94.9% negative predictive value using BASIC criteria. Overall strength of interobserver agreement was high: kappa 0.89 (0.82-0.96). Agreement for the individual criteria was as follows: surface mucus (93.8%), regularity (65.6%), type of pit (40.6%), pit visibility (66.9%), pit distribution (57%), vessel visibility (73%), and being lacy (46%) and peri-cryptal (61%). The confidence in diagnosis was rated at high ≥4 in 67% of the cases. CONCLUSIONS A group of US-based endoscopy experts have validated a simple and easily reproducible BLI classification system to characterize colorectal polyps with >90% accuracy and a high level of interobserver agreement.

BACKGROUND AND AIM Volumetric laser endomicroscopy (VLE) is used to identify Barrett's esophagus (BE) dysplasia. Selection of a dysplastic region of interest (ROI) can be challenging due to feature variability across a large amount of data. The degree of agreement among VLE users in selecting a ROI has not been studied. METHODS High-definition videos that divided a VLE scan from 18 patients with biopsy-proven BE dysplasia into 1-cm segments were reviewed using a four-quadrant grid superimposed for systematic interpretation. VLE scans were selected based on image quality and appropriate visualization of BE epithelium. Four experienced VLE users rated each quadrant as dysplastic or non-dysplastic. For quadrants rated as dysplastic, reviewers selected a single timeframe with representative features. A high-degree of agreement among reviewers was defined as ≥75% agreement on the quadrant diagnosis and ≥50% agreement on selected timeframe (±2 s). RESULTS Thirty-one videos, each 32 s in length, comprising 124 quadrants were reviewed. There was high-agreement among reviewers in 99 (80%) quadrants, of which 68 (69%) were rated as dysplastic. Compared with quadrants rated as non-dysplastic, ROIs of quadrants rated as dysplastic contained a higher number of epithelial glands (12.7 vs 1.2, P

Volumetric laser endomicroscopy (VLE) is used to identify Barrett's esophagus (BE) dysplasia. Selection of a dysplastic region of interest (ROI) can be challenging due to feature variability across a large amount of data. The degree of agreement among VLE users in selecting a ROI has not been studied.High-definition videos that divided a VLE scan from 18 patients with biopsy-proven BE dysplasia into 1-cm segments were reviewed using a four-quadrant grid superimposed for systematic interpretation. VLE scans were selected based on image quality and appropriate visualization of BE epithelium. Four experienced VLE users rated each quadrant as dysplastic or non-dysplastic. For quadrants rated as dysplastic, reviewers selected a single timeframe with representative features. A high-degree of agreement among reviewers was defined as ≥75% agreement on the quadrant diagnosis and ≥50% agreement on selected timeframe (±2 s).Thirty-one videos, each 32 s in length, comprising 124 quadrants were reviewed. There was high-agreement among reviewers in 99 (80%) quadrants, of which 68 (69%) were rated as dysplastic. Compared with quadrants rated as non-dysplastic, ROIs of quadrants rated as dysplastic contained a higher number of epithelial glands (12.7 vs 1.2, P 0.001) with atypical architecture (54 vs 1, P 0.001). A statistically significant difference was observed between the signal intensity profiles of quadrants rated as dysplastic and quadrants rated as non-dysplastic (P = 0.004).This study highlights that experienced VLE users can identify ROIs with high-degree of agreement. Selected ROIs contained VLE features associated with BE dysplasia.

Background and Aims Positron emission tomography with computed tomography (PET/CT) has been used to detect metastasis in the diagnosis of esophageal adenocarcinoma (EAC). However, the utility of PET/CT to assess primary tumor for endoscopic resectability and prognosis in early EAC remains unclear. We conducted a retrospective study to determine the association of PET/CT findings with histopathological tumor invasion depth and survival outcomes. Methods EAC patients who underwent PET/CT followed by endoscopic mucosal resection (EMR) were included. Pathology on EMR and survival outcomes from a prospectively maintained database was retrieved. Two radiologists independently reviewed the PET/CT using the following parameters: detection of malignancy, fluorodeoxyglucose (FDG) uptake intensity, FDG focality, FDG eccentricity, esophageal thickness, maximal standard uptake value (SUVmax), and SUVmax ratio (lesion/liver). Results There were 72 eligible patients: 42 (58.3%) had T1a lesions, and 30 (41.7%) had ≥ T1b. Only SUVmax ratio was associated with tumor invasion depth (odds ratio = 2.77, 95% confidence interval 1.26–7.73, P = 0.0075). Using a cut-off of 1.48, the sensitivity and specificity of SUVmax ratio for identification of T1a lesions were 43.3% and 80.9%, respectively. Adjusting the SUVmax ratio to 2.14, 16.7% (5/30) of ≥ T1b patients were identified without any false-positive cases. Multivariate analysis showed SUVmax ratio, Charlson comorbidity index, and esophagectomy were independent predictors for survival. Conclusions SUVmax ratio (lesion/liver) is more accurate in predicting endoscopic resectability and mortality for EAC than other PET/CT parameters and appears promising as a useful adjunct to the current diagnostic work-up.

Background and Aims: Aberrant right subclavian artery (ARSA) is the most common congenital anomaly of the aortic arch occurring in 0.4–2.0% of the general population. Instead of arising from the brachiocephalic artery, the ARSA arises as the last branch from the aortic arch. The aim of this study was to determine the prevalence of ARSA in patients undergoing upper endoscopic ultrasound (EUS) and to describe the EUS characteristics of ARSA. Methods: A retrospective review was conducted of 7513 upper EUS exams performed from 1 July 2000 to 1 February 2005. Results: In total, 27 (0.36%, 95% CI 0.22–0.50%) of 7513 patients undergoing upper EUS were found to have an ARSA (10 male, 17 female; mean age 58 years, range 23–81 years). Of the 27 patients, 16 had only radial EUS, 10 had radial and linear EUS, and one had only linear EUS. In all 26 patients who underwent radial imaging, a well-defined, anechoic tubular structure was seen originating from the aortic arch and passing between the esophagus and spine. In all 11 patients undergoing linear imaging, the abnormal anatomy was detected and the vascular nature confirmed by Doppler. In one patient, both radial and linear imaging identified unsuspected aneurismal dilatation of the ARSA; a rare condition referred to as Kommerell’s diverticulum (KD). None of the other 26 patients had symptoms to suggest an ARSA. Of the 14 patients who had computed tomography (CT) prior to EUS, only four were initially reported to have ARSA. However, later review of the CT scans verified an ARSA in all 14 patients. Of the two patients who underwent a barium swallow, only one had findings suggestive of ARSA. Conclusions: This report highlights the utility of both radial and linear EUS imaging in identifying previously unsuspected ARSA and associated anomalies. This report also suggests the need for careful review of the CT in patients suspected of having ARSA due to the frequent failure of radiologists to identify, or report, this anomaly when particular focus is not given.

Positron emission tomography with computed tomography (PET/CT) has been used to detect metastasis in the diagnosis of esophageal adenocarcinoma (EAC). However, the utility of PET/CT to assess primary tumor for endoscopic resectability and prognosis in early EAC remains unclear. We conducted a retrospective study to determine the association of PET/CT findings with histopathological tumor invasion depth and survival outcomes.EAC patients who underwent PET/CT followed by endoscopic mucosal resection (EMR) were included. Pathology on EMR and survival outcomes from a prospectively maintained database was retrieved. Two radiologists independently reviewed the PET/CT using the following parameters: detection of malignancy, fluorodeoxyglucose (FDG) uptake intensity, FDG focality, FDG eccentricity, esophageal thickness, maximal standard uptake value (SUVmax), and SUVmax ratio (lesion/liver).There were 72 eligible patients: 42 (58.3%) had T1a lesions, and 30 (41.7%) had ≥ T1b. Only SUVmax ratio was associated with tumor invasion depth (odds ratio=2.77, 95% confidence interval 1.26-7.73, P=0.0075). Using a cut-off of 1.48, the sensitivity and specificity of SUVmax ratio for identification of T1a lesions were 43.3% and 80.9%, respectively. Adjusting the SUVmax ratio to 2.14, 16.7% (5/30) of ≥ T1b patients were identified without any false-positive cases. Multivariate analysis showed SUVmax ratio, Charlson comorbidity index, and esophagectomy were independent predictors for survival.SUVmax ratio (lesion/liver) is more accurate in predicting endoscopic resectability and mortality for EAC than other PET/CT parameters and appears promising as a useful adjunct to the current diagnostic work-up.

Background: Photodynamic therapy (PDT) has demonstrated promise in the palliative treatment of advanced cholangiocarcinoma. The aim of this pilot study was to assess the outcome in patients with non-resectable cholangiocarcinoma following endoscopic application of PDT directly into the biliary tract. Methods: In patients with advanced cholangiocarcinoma, endoscopic retrograde cholangiopancreatography (ERCP) was performed to define the proximal and distal extent of intraductal tumor. Sodium porfimer was administered intravenously to all patients. Forty-eight hours later, a commercially available cylindrical diffusing laser fiber (1–2.5 cm in length, OptiGuide) designed for esophageal use was advanced across the biliary strictures. Laser light was applied at a power of 400 mW/cm fiber for a total energy of 180 J/cm2 using an argon-pumped tunable dye laser. Patients received endoscopic PDT every 3 months provided they maintained a favorable performance status. Plastic biliary stents were replaced immediately following light application and were maintained in all patients. Results: Using a preloaded catheter, adequate positioning of the laser fiber was achieved in all patients. Eight patients with advanced cholangiocarcinoma received a total of 19 PDT treatments, range 1–5 treatments/patient. All eight patients were followed until death; mean follow-up was 9.8 months. Median survival from the date of the first PDT treatment was 276 days, which compares favorably with published series that have reported median survival times between 45 and 127 days for patients with bismuth type III and IV tumors treated with stenting alone. Conclusions: Endoscopic application of PDT demonstrates promise in prolonging survival in patients with advanced cholangiocarcinoma. Additional randomized clinical trials using commercially available fibers are needed to fully evaluate both the optimum frequency and treatment interval of endoscopic PDT in the management of advanced cholangiocarcinoma.