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Goals: To estimate the accuracy of probe-based confocal laser endomicroscopy (pCLE) and narrow band imaging (NBI), individually and in combination, for classification of duodenal polyps., Background: Ex vivo pathologic diagnosis of duodenal polyps causes time delay, requiring separate procedures for diagnosis and therapy. It also involves small risk of pancreatitis in ampullary adenomas and can make subsequent endoscopic mucosal resection more difficult by "tacking down" mucosa. In vivo diagnosis with pCLE and NBI may avoid these complications and may guide immediate therapy., Study: During high-definition white light endoscopy, 1 endoscopist (M.B.W.) performed NBI and then, pCLE of duodenal sites. Matched tissue sampling or endoscopic mucosal resection was performed. Confocal videos were recorded, de-identified, and reviewed by same endoscopist, blinded to histopathology, 1 month later. Confocal features of dysplasia in Barrett esophagus were applied for detection of duodenal dysplasia., Results: Of 65 sites from 36 participants, 24 lesions showed dysplasia, whereas 41 polyps and control sites were nondysplastic on histopathology, used as standard reference. The accuracy, sensitivity, and specificity of pCLE were 83%, 92%, and 78%, whereas that of NBI were 80%, 83%, and 78%, respectively. In subset of 49 lesions with similar pCLE and NBI diagnosis, the accuracy, sensitivity, and specificity, improved significantly and was found to be 92%, 95%, and 90%, respectively., Conclusions: Our study suggests that pCLE has superior sensitivity as compared with NBI for detection of dysplasia in duodenal polyps. Combined accuracy of pCLE and NBI approaches that of ex vivo pathology, which may help in avoiding biopsy sampling.

Background and Study Aims: Probe-based confocal laser endomicroscopy (pCLE) is a new imaging modality that enables histological examination of gastrointestinal mucosa during endoscopic procedures. Most studies have evaluated offline interpretation of pCLE images. In clinical practice, real-time interpretation is necessary to assist decision-making during the procedure. The aim of this pilot study was to compare the accuracy of real-time pCLE diagnosis made during the procedure with that of blinded offline interpretation to provide accuracy estimates that will aid the planning of future studies., Patients and Methods: pCLE was performed in patients undergoing screening and surveillance colonoscopy. Once a polyp had been identified, one endoscopist analyzed pCLE images during the procedure and made a provisional "real-time" diagnosis. Saved video recordings were de-identified, randomized, and reviewed "offline" 1 month later by the same endoscopist, who was blinded to the original diagnoses., Results: Images from a total of 154 polyps were recorded (80 neoplastic, 74 non-neoplastic). The overall accuracy of real-time pCLE diagnosis (accuracy 79%, sensitivity 81%, specificity 76%) and offline pCLE diagnosis (83%, 88%, and 77%, respectively) for all 154 polyps were similar. Among polyps < 10 mm in size, the accuracy of real-time interpretation was significantly lower (accuracy 78%, sensitivity 71%, specificity 83%) than that of offline pCLE interpretation (81%, 86%, 78%, respectively). For polyps ≥ 10 mm, the accuracy of pCLE diagnosis in real-time was better (accuracy 85%, sensitivity 90%, specificity 75%) than offline pCLE diagnosis (81%, 97%, and 50%, respectively)., Conclusions: These results suggest that real-time and offline interpretations of pCLE images are moderately accurate. Real-time interpretation is slightly less accurate than offline diagnosis, but overall both are comparable. Additionally, there was contrasting accuracy between the two methods for small and large polyps., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Residual neoplasia after EMR of colorectal lesions is common. There is a critical need for imaging methods to accurately diagnose residual disease and to guide retreatment in real time., Objective: The aim was to estimate and compare the accuracy of virtual chromoendoscopy (VCE) and probe-based confocal laser endomicroscopy (pCLE) for detection of residual neoplastic tissue at the site of prior EMR., Design: Prospective, blind, pilot comparison of advanced endoscopic imaging (VCE and pCLE) by using matching histology as reference standard., Setting: Three tertiary-care referral hospitals., Patients: This study involved 92 participants who underwent follow-up colonoscopies for the evaluation of prior EMR sites within 1 year., Intervention: The EMR scars were assessed during follow-up high-resolution colonoscopy by using VCE (narrow-band imaging/Fujinon Intelligent Color Enhancement [FICE]), and pCLE. Confocal videos of EMR scars were interpreted in real time and were also stored and reviewed offline, blinded to histopathology and endoscopic appearance. Tissue confirmation by biopsies or polypectomy/repeat EMR was performed in all cases., Main Outcome Measurements: Sensitivity, specificity, and accuracy for VCE and pCLE alone and in combination against histopathology as the standard reference standard., Results: Among 129 EMR scars, residual neoplasia was confirmed by histology in 29 sites (22%). For VCE, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 72%, 77%, 49%, 91%, and 77%, respectively, and were 97%, 77%, 55%, 99%, and 81% for pCLE (P = .045 for sensitivity). When only EMR scars for which VCE and pCLE agreed on the diagnosis were analyzed (95/129 scars), the accuracy, sensitivity, specificity, PPV, and NPV of pCLE and VCE were 90%, 100%, 87%, 67%, and 100%, respectively., Limitations: Small sample size, lack of power, involvement of highly experienced pCLE experts., Conclusion: Confocal endomicroscopy significantly increases the sensitivity for detecting residual neoplasia after colorectal EMR compared with endoscopy alone. When confocal endomicroscopy is used in combination with VCE, the accuracy is extremely high, and sensitivity approaches that of histopathology. Together, they may reduce the need for histologic examination and allow a highly accurate on-table decision to treat again or not, thus avoiding unnecessary repeat procedures. (, Clinical Trial Registration Number: 00874263.)., (Copyright © 2012 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Objectives: Probe-based confocal laser endomicroscopy (pCLE) allows real-time in-vivo microscopic imaging of tissue. Narrow band imaging (NBI) can also classify colorectal lesions. Both systems may allow accurate optical diagnosis of small (6-9 mm) and diminutive (1-5 mm) polyps without histopathology. This study assesses the accuracy of pCLE and NBI for prediction of histology., Methods: Participants underwent high-definition colonoscopy. The surface pit pattern of all polyps (1-9 mm) was determined in vivo using NBI. Confocal videos were obtained after administration of IV fluorescein. Recorded videos were subsequently analyzed offline, blinded to endoscopic characteristics, and histopathology. Confocal images were classified as neoplastic and non-neoplastic according to the Miami classification system., Results: A total of 130 polyps (58 neoplastic, 72 non-neoplastic, mean size 4.6 mm) from 65 patients were assessed. Assuming histopathology as gold standard, pCLE had higher sensitivity than NBI (86% vs. 64%, P=0.008), with lower specificity (78% vs. 92%, p=0.027) and similar overall accuracy (82% vs. 79%, P=0.59). When 65 high-confidence cases were analyzed (polyps diagnosed identically with pCLE and NBI and with high-quality confocal videos), sensitivity and specificity were 94 and 97%., Conclusions: pCLE demonstrated higher sensitivity in predicting histology of small polyps compared with NBI, whereas NBI had higher specificity. When used in combination, the accuracy of pCLE and NBI was extremely high, approaching the accuracy of histopathology. Together, they may reduce the need for histological examination. However, further studies are warranted to evaluate the role of these techniques, especially in the population-based colon cancer screening.

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., (Copyright © 2011. Published by Mosby, Inc.)

Background and Study Aims: A recently developed probe-based, confocal laser endomicroscopy (pCLE) system provides images of surface colonic epithelium in vivo during any endoscopy. Our objective was to assess interobserver agreement, sensitivity, specificity, and overall accuracy in the diagnosis of neoplasia using pCLE., Patients and Methods: 53 patients undergoing surveillance and screening colonoscopies were enrolled. A total of 75 lesions, were detected and all were inspected by pCLE prior to sampling or polypectomy. Intravenous fluorescein was used to optimize tissue contrast. Three pCLE users, blinded to histopathologic and endoscopic findings, reviewed the set of video sequences for crypt architecture, vessel architecture, and colorectal neoplasia diagnosis. Histopathologic diagnosis from the corresponding biopsies was the reference gold standard., Results: Of the 75 colorectal lesions, 50 were neoplastic and 25 non-neoplastic. Interobserver agreement was moderate to good for the classification of neoplasia (kappa 0.55, 78 % pairwise agreement), and moderate for vessel architecture (kappa 0.41, 67 % pairwise agreement) and crypt architecture (kappa 0.49, 69 % pairwise agreement). In distinguishing between neoplastic and non-neoplastic lesions, sensitivity, specificity, and accuracy were 76 %, 72 % and 75 %, respectively. When videos of good or excellent quality only were considered, interobserver agreement for classification of neoplasia was higher (kappa 0.83, 92 % pairwise agreement), as were sensitivity (88 %), specificity (89 %), and accuracy (88 %)., Conclusion: An international collaboration group had moderate to good interobserver agreement using a pCLE system to predict neoplasia, which is acceptable for this study., (Georg Thieme Verlag KG Stuttgart. New York.)

Background & Aims: Probe-based confocal laser endomicroscopy (pCLE) allows in vivo imaging of tissue at micron resolution. Virtual chromoendoscopy systems, such as Fujinon intelligent color enhancement and narrow band imaging, also have potential to differentiate neoplastic colorectal lesions. The accuracy of these systems in clinical practice is, however, unknown. Our primary aim was to compare sensitivity and specificity of pCLE to virtual chromoendoscopy for classification of colorectal polyps using histopathology as a gold standard. A secondary aim was to compare sensitivity and specificity of pCLE to virtual chromoendoscopy using a modified gold standard that assumed that all polyps >/=10 mm had malignant potential and were considered neoplastic or high risk., Methods: Patients underwent colonoscopy using high-resolution colonoscopes. The surface pit pattern was determined with NBI or FICE in all patients. Confocal images were recorded and subsequently analyzed offline, blinded to the endoscopic characteristics and histopathology. Each polyp was diagnosed as benign or neoplastic based on confocal features according to modified Mainz criteria., Results: A total of 119 polyps (81 neoplastic, 38 hyperplastic) from 75 patients was assessed. The pCLE had higher sensitivity compared to virtual chromoendoscopy when considering histopathology as gold standard (91% vs 77%; P = .010) and modified gold standard (88% vs 76%; P = .037). There was no statistically significant difference in specificity between pCLE and virtual chromoendoscopy when considering histopathology or modified gold standard., Conclusions: Confocal endomicroscopy demonstrated higher sensitivity with similar specificity in classification of colorectal polyps. These new methods may replace the need for ex vivo histological confirmation of small polyps, but further studies are warranted., (Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)