Citations

Abstract Background An oral formulation of methylene blue with colonic delivery (MB-MMX) has been developed to increase detection of colorectal polys during colonoscopy. Traditionally, there have been safety concerns regarding DNA damage when methylene blue is exposed to white light. The aim of this study was to evaluate DNA damage in colonic mucosa after MB-MMX chromoendoscopy. Methods This was an open-label phase II safety study to assess for genotoxicity on colorectal biopsies of patients undergoing two sequential colonoscopies before and after an oral dose of 200 mg MB-MMX added to their bowel prep. Analysis of a biomarker of double-stranded DNA breaks, γH2AX, was performed on biopsy specimens. Results Ten patients were included in the study. The mean expression of γH2AX ± 95 % confidence intervals of the 50 biopsies before and after MB-MMX administration were 0.58 ± 0.08 and 0.62 ± 0.09, respectively (P = 0.24). None of the analyzed samples showed excess positive γH2AX expression, confirming the absence of DNA damage on biopsies after methylene blue exposure. No deaths or serious adverse events occurred. Conclusions An oral dose of 200 mg of MB-MMX did not result in any detectable DNA damage.

Abstract Background Volumetric laser endomicroscopy (VLE) provides circumferential images 3 mm into the biliary and pancreatic ducts. We aimed to correlate VLE images with the normal and abnormal microstructure of these ducts. Methods: Samples from patients undergoing hepatic or pancreatic resection were evaluated. VLE images were collected using a low-profile VLE catheter inserted manually into the biliary and pancreatic ducts ex vivo. Histological correlation was assessed by two unblinded investigators. Results 25 patients (20 liver and 5 pancreatic samples) and 111 images were analyzed. VLE revealed three histological layers: epithelium, connective tissue, and parenchyma. It identified distinctive patterns for primary sclerosing cholangitis (PSC), pancreatic cysts, neuroendocrine tumor, and adenocarcinoma adjacent to the pancreatic duct or ampulla. VLE failed to identify dysplasia in a dominant stricture and inflammatory infiltrates in PSC. Reflectivity measurements of the liver parenchyma diagnosed liver cirrhosis with high sensitivity. Conclusions VLE can identify histological changes in the biliary and pancreatic ducts allowing real-time diagnosis. Further studies are needed to measure the accuracy of VLE in a larger sample and to validate our findings in vivo.

Pancreas cancer is a lethal cancer as the majority patients are diagnosed at an advanced incurable stage. Despite improvements in diagnostic modalities and management strategies, including surgery and chemotherapies, the outcome of pancreas cancer remains poor. Endoscopic ultrasound (EUS) is an important imaging tool for pancreas cancer. For decades, resected pancreas cancer and other cancer specimens have been used to identify tissue biomarkers or genomics for precision therapy; however, only 20% of patients undergo surgery, and thus, this framework is not useful for unresectable pancreas cancer. With advancements in needle technologies, tumor specimens can be obtained at the time of tissue diagnosis. Tumor tissue can be used for development of personalized cancer treatment, such as performing whole exome sequencing and global genomic profiling of pancreas cancer, development of tissue biomarkers, and targeted mutational assays for precise chemotherapy treatment. In this review, we discuss the recent advances in tissue acquisition of pancreas cancer.

Abstract Background and study aims Risk factors for colorectal adenoma recurrence after endoscopic mucosal resection (EMR) have been well documented. We assessed the efficacy of the newer 190 colonoscope versus the standard 180 colonoscope for complete resection of lateral spreading lesions. Patients and methods A single-center, retrospective study of patients who underwent EMR with Olympus 180 or 190 colonoscopes from January 1, 2010 to September 30, 2016. We included patients with lesions ≥ 20 mm and surveillance colonoscopy (SC1) after index EMR. A propensity score approach with inverse probability weighting was used to control for potential confounders. A secondary aim was to identify risk factors for recurrence and assess the applicability of the Sydney EMR recurrence tool (SERT) by grading each lesion of our cohort and analyzing associations with recurrence. Results Two hundred ninety-one lesions met inclusion criteria for the study. Odds ratio (OR) for recurrence with the 190 colonoscope was 1.06 (P = .85). Adenoma size (P = .02) and use of argon plasma coagulation (APC; P < .001) were risk factors for recurrence. Lesions with SERT scores > 0 had a higher recurrence risk during follow-up (32 % vs 21 %; OR 1.71; P = .05). Lesions with SERT scores = 0 reached a plateau for recurrence at 12 and 18 months in Kaplan-Meier curves. Conclusions The use of 190 colonoscopes did not measurably affect adenoma recurrence at SC1. Recurrence was associated with adenoma size, complementary APC for resection, and SERT scores > 0. Lesions with SERT scores = 0 that remain negative for recurrence at 18 months may return to routine surveillance.

Abstract Background and study aims Little is known about the learning curve for image interpretation in volumetric laser endomicroscopy (VLE) in Barrett’s esophagus (BE). The goal of this study was to calculate the learning curve, competence of image interpretation, sensitivity, specificity, and accuracy of VLE among novice users. Methods 31 novice users viewed 96 VLE images electronically at three academic institutions after a brief training session. There were 24 images of each histologic type: normal gastric cardia, normal esophageal squamous epithelium, non-neoplastic BE, and neoplastic BE. The users were asked to identify the correct tissue type and level of confidence. The cumulative summation (CUSUM) technique was used to construct a learning curve. Results 22 (71 %) of the physicians achieved VLE interpretation competency during their 96-slide review. Half of the physicians achieved competency at 65 images (95 % confidence interval [CI] 45 – 85). There was a statistically significant association between confidence in diagnosis and selecting the correct histologic tissue type (P < 0.001). The median accuracy for esophageal squamous epithelium, normal gastric cardia, non-neoplastic BE, and neoplastic BE was 96 % (95 %CI 95 % – 96 %), 95 % (95 %CI 94 % – 96 %), 90 % (95 %CI 88 % – 91 %), 96 % (95 %CI 95 % – 96 %). The overall accuracy was 95 % (95 %CI 93 % – 95 %). Conclusion The majority of novice users achieved competence in image interpretation of VLE for BE, using a pre-selected image set, with a favorable learning curve after a brief training session. An electronic review of VLE images, prior to real-time use of VLE, is encouraged.

Background Accurate staging of pancreatic cancer is essential for surgical planning and for identification of locally advanced and metastatic disease that is incurable by surgery. Advances in endoscopic sonography (EUS), computed tomography (CT), and positron emission tomography have improved the accuracy of staging and reduced the number of incomplete surgical resections. Tissue acquisition is necessary in nonsurgical cases when chemoradiotherapy is considered. The complex regional anatomy of the pancreas makes cytologic diagnosis of malignancy at this region difficult without exploratory surgery. Although CT-guided fine-needle aspiration (FNA) is used for this purpose, reports of an increased risk of peritoneal dissemination of cancer cells and a false-negative rate of nearly 20% make this a poor choice. The ability to position the EUS-transducer in direct proximity to the pancreas by means of the stomach and duodenum, combined with the use of FNA, increases the specificity of EUS in detecting pancreatic malignancies. Methods The current literature regarding the accuracy of EUS with FNA in the evaluation of pancreatic cancer is reviewed. Results EUS accuracy ranges from 78% to 94% for tumor staging and from 64% to 82% for nodal staging. EUS also enables FNA of lesions that are too small to be identified by CT or MRI or too well encased by surrounding vascular structures to safely allow percutaneous biopsy. The accuracy for detecting invasion into the superior mesenteric artery and vein is lower than that for detecting portal or splenic vein invasion, especially for large tumors. EUS permits delivery of localized therapy such as celiac plexus neurolysis for pain control and direct intra-lesional injection of antitumor therapy. Conclusions EUS in combination with FNA is a highly accurate method of preoperative staging of pancreatic cancer, especially those too small to be characterized by CT or MRI, and it has the ability to obtain cytological confirmation of pancreatic cancer.

Detection of early colorectal cancer is expected to rise in light of national colorectal cancer screening programs. This The present review article delineates current endoscopic risk assessments, differentiating invasive from non‐invasive neoplasia, for high likelihood of lymph node metastasis in early colorectal cancer, also termed high‐risk early colorectal cancer, and endoscopic and surgical resection methods from a Western hemisphere perspective.