Background Discriminating neoplastic from non-neoplastic polyps can significantly reduce the cost of colonoscopy. The American Society for Gastrointestinal Endoscopy (ASGE) recently set threshold ...levels for optical diagnostic accuracy to be acceptable for clinical use. Objective In this study, we compare a novel colonoscope capable of dual-focus imaging with standard colonoscopy with respect to the ASGE guidelines. Setting An academic medical center ambulatory surgical center. Patients and Interventions Patients at average risk were randomized to standard colonoscopy (Olympus CF-H180 and Exera II 180 colonoscopes, Olympus America, Center Valley, Pa) or dual-focus colonoscopy (Olympus CF-HQ190 and Exera III 190 colonoscopes, Olympus America). All polyps were given an optical diagnosis and compared with histology. Results A total of 600 patients were consented and 522 completed all aspects of the procedure. A total of 927 polyps were analyzed. Optical diagnostic accuracy was 79% (95% confidence interval, 74%-83%) for the 190 and 77% (95% confidence interval, 73%-81%) for the 180 colonoscope. Adenoma detection rates were also similar between the 2 groups (50% for the 190 vs 52% for the 180 colonoscope). For small distal rectosigmoid polyps with a high confidence diagnosis, the negative predictive value for adenoma was 96% (range 89%-99%) for the 180 in the narrow-band imaging (NBI) mode and 97% (range 88%-99%) for the 190 colonoscope in NBI mode. Agreement of surveillance intervals by using optical diagnosis was 94% to 95% for all modalities (180 and 190 colonoscopes, white light imaging, NBI). Limitations Our study evaluated the accuracy of the 180 and 190 colonoscopes at a center with already-established expertise in endoscopic imaging. Conclusions Both traditional and new dual-focus colonoscopes provide highly accurate optical polyp discrimination. There was no difference between the 2 systems in terms of discrimination or adenoma detection. Both systems are consistent with ASGE guidelines for optical diagnosis of selected colorectal polyps without histological confirmation.
Background Probe-based confocal laser endomicroscopy (pCLE) is an emerging tool for in vivo imaging of the GI tract that requires the endoscopist to interpret microscopic images. The learning curve ...for interpretation of pCLE images is unknown. Objective To examine the learning curve of correctly identifying benign and neoplastic colorectal lesions by using pCLE and to evaluate the learning curve of obtaining high-quality images. Design Prospective, double-blind review of pCLE images of 76 colorectal lesions by using corresponding polypectomies as the reference standard. A training set of 20 images with known histology was first reviewed to standardize image interpretation, followed by blinded review of 76 unknown images. Setting Eleven endoscopists from 3 different endoscopy centers evaluated the images obtained by 1 endoscopist using the high-definition confocal probe. Patients Patients undergoing screening and surveillance colonoscopies. Intervention Intravenous fluorescein pCLE imaging of colorectal lesions followed by polypectomies. Main Outcome Measurements Accuracy of image interpretation with constructing learning curve for pCLE image interpretation and acquisition. Results Of the 76 colorectal lesions, 51 (67%) were neoplastic and 25 (33%) were benign, based on histopathology. Accuracy for the overall group was 63% for lesions 1 to 20, 64% for lesions 21 to 40, 79% for lesions 41 to 60, and 86% for lesions 61 to 76. The ability to obtain high-quality images was stable over the 76 cases. Limitations Small sample size and use of offline video sequences. Conclusions Accurate interpretation of pCLE images for predicting neoplastic lesions can be learned rapidly by a wide range of GI specialists. Furthermore, the ability to acquire high-quality pCLE images is also quickly learned.
Complex neurologic phenotypes are inherently difficult to diagnose. Whole-exome sequencing (WES) is a new tool in the neurologist's diagnostic armamentarium. Whole-exome sequencing can be applied to ...investigate the "diagnostic odyssey" cases. These cases involve patients with rare diseases that likely have a genetic etiology but have failed to be diagnosed by clinical evaluation and targeted gene testing. We describe such a case, a 22-year-old man who had mild intellectual developmental disability and episodes of jerking ataxic movements that affected his whole body. He underwent numerous multidisciplinary and multicentric evaluations throughout his life that failed to establish a clear diagnosis. Following his visit to Mayo Clinic in Jacksonville, Florida, WES was applied for genetic determination of the unknown disorder in the proband and his biological parents and sister. Additional clinical evaluation, magnetic resonance neuroimaging, electromyography, and electroencephalography of the proband were performed to verify the phenotype after the WES results were available. To our knowledge, this is the first report of the application of WES to facilitate the diagnosis of episodic ataxia type 1. This case illustrates that WES supported by clinical data is a useful and time-saving tool in the evaluation of patients with rare and complex hereditary disorders.
To understand motivations, educational needs, and concerns of individuals contemplating whole-exome sequencing (WES) and determine what amount of genetic information might be obtained by sequencing a ...generally healthy cohort so as to more effectively counsel future patients.
From 2012 to 2014, 40 medically educated, generally healthy scientists at Mayo Clinic were invited to have WES conducted on a research basis; 26 agreed to be in a drawing from which 10 participants were selected. The study involved pre- and posttest genetic counseling and completion of 4 surveys related to the experience and outcomes. Whole-exome sequencing was conducted on DNA from blood from each person.
Most variants (76,305 per person; range, 74,505-77,387) were known benign allelic variants, variants in genes of unknown function, or variants of uncertain significance in genes of known function. The results of suspected pathogenic/pathogenic variants in Mendelian disorders and pharmacogenomic variants were disclosed. The mean number of suspected pathogenic/pathogenic variants was 2.2 per person (range, 1-4). Four pharmacogenomic genes were included for reporting; variants were found in 9 of 10 participants.
This study provides data that may be useful in establishing reality-based patient expectations, outlines specific points to cover during counseling, and increases confidence in the feasibility of providing adequate preparation and counseling for WES in generally healthy individuals.
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