J Gastrointestin Liver Dis, September 2017 Vol. 26 No 3: 291-297 1) Division of Gastroenterology and Hepatology, Department of Internal Medicine, Albert Einstein Medical Center, Philadelphia, PA; 2) Department of Internal Medicine, Albert Einstein Medical Center, Philadelphia, PA; 3) Department of Pathology, Baylor College of Medicine, Houston, Texas; 4) Division of Gastroenterology, Hepatology and Nutrition, University of Texas Health Science Center at Houston, Houston, Texas, USA Address for correspondence: Shashideep Singhal, MD Division of Gastroenterology, Hepatology and Nutrition, University of Texas Health Science Center at Houston, 6431 Fannin, MSB 4.234, Houston, Texas, USA 77030 sdsinghal@gmail.com Received: 20.05.2017 Accepted: 12.07.2017 Volumetric Laser Endomicroscopy for Barrett’s Esophagus – Looking at the Fine Print Deepanshu Jain 1 , Sanna Fatima 2 , Shilpa Jain 3 , Shashideep Singhal 4 INTRODUCTION Barrett’s esophagus (BE) is a premalignant condition characterized by intestinal metaplasia that replaces the normal squamous epithelium. Barrett’s esophagus develops in association with chronic gastroesophageal refux disease (GERD). Chronic GERD and BE are considered major risk factors for the development of esophageal adenocarcinoma (EAC) [1, 2]. Te true prevalence of BE is difcult to assess as most patients are asymptomatic and it is only detected on endoscopic evaluation. Te incidence of EAC REVIEW ABSTRACT Barrett’s esophagus (BE) is a premalignant condition. Te incidence of adenocarcinoma in BE has been reported to be between 0.1-3%. Dysplasia in BE is patchy and extensive biopsy sampling is labor intensive, low yield and does not eliminate the sampling error completely. Volumetric laser endomicroscopy (VLE) is expected to enable endoscopists to do targeted biopsy of dysplastic/cancerous lesions (not visible on white light endoscopy) among patients with BE. We reviewed 7 studies with a total of 62 subjects who had undergone VLE. Of 34 patients with available data, VLE correlated with histology in 17 subjects (50%). It missed the underlying diagnosis in one subject (2.9%). VLE led to inadvertent biopsy in 16 patients (47.1%), and led or would have led to upstaging of disease in 11 subjects (32.4%). In the entire cohort, the sensitivity, specifcity, positive predictive value and negative predictive value (NPV) of VLE for diagnosis of dysplasia, buried Barrett’s or intramucosal carcinoma was 92.3%, 23.8%, 42.9% and 83.3%, respectively. High sensitivity and NPV can potentially help space out the surveillance intervals. Low specifcity does lead to a high number of biopsies, which are likely less than non targeted biopsies. Volumetric laser endomicroscopy is a safe and sensitive test to identify mucosal lesions in patients with BE which are invisible under standard white light endoscopy. Key words: Volumetric laser endomicroscopy – Barrett’s esophagus – esophageal adenocarcinoma. Abbreviations: BE: Barrett’s Esophagus; BB: Buried Barrett’s; EAC: Esophageal adenocarcinoma; EDS: Evans Dysplasia Score; EMR: Endoscopic Mucosal Resection; GERD: Gastro-esophageal refux disease; HGD: High grade dysplasia; IMC: Intra-mucosal adenocarcinoma; LGD: Low grade dysplasia; NBI: Narrow Band Imaging; OCT-SI: Optical Coherence Tomography Scoring Index; RFA: Radiofrequency ablation; SGS: Sub-squamous glandular structures; VLE: Volumetric Laser Endomicroscopy; WLE: White Light Endoscopy. Available from: http://www.jgld.ro/wp/archive/y2017/n3/a14/ DOI: http://dx.doi.org/10.15403/jgld.2014.1121.263.jai in BE has been reported to be between 0.1-3% [3-6]. In recent decades, the incidence of EAC has been increasing despite current screening guidelines [7, 8]. Te primary strategy to prevent death from EAC has been to perform endoscopy in high-risk patients with GERD to detect BE and in patients with BE to perform surveillance endoscopies at regular interval to detect neoplasia [9]. Te current gold standard for surveillance in patients with BE is random 4-quadrant biopsy every 1-2 cm. If any irregularities such as nodules are noted, then endoscopic mucosal resection (EMR) is performed [10]. Dysplasia in BE is patchy in extent and severity and can be missed because of sampling error [11-14]. Extensive biopsy sampling is labor intensive, low yield and does not eliminate the sampling error completely. In addition, when dysplasia is detected, foci of invasive cancer may be missed [15-17]. Several advanced techniques have been proposed to enhance the identifcation of dysplastic areas in BE [18]. Advanced endoscopic imaging enables targeted biopsies and improves accuracy of endoscopic surveillance and may