Department of Equine and Small Animal Medicine Faculty of Veterinary Medicine Helsinki University Finland CHROMOENDOSCOPY Principles and indications Marcus Vinicius Candido DVM, MSc 9.5.2017 1
White light endoscopy (WLE) Limitations Low correlation of macroscopic findings with Histology (Craven et al. 2004, Day et al. 2008, Washabau et al 2010) Treatment response to diet or medication (Schreiner et al. 2008) Clinical outcome (Allenspach et al. 2007) 25.5.2017 2
WLE Limitations May not reveal focal changes Discrete discoloration Minor changes in texture Flat or depressed lesions Limited application for directed (targeted) biopsy Random / standard sampling when no obvious changes are seen 25.5.2017 3
White light endoscopy (WLE) Limitations Precursor lesions of gastrointestinal neoplasia might be overlooked (Coda & Thillainayagam 2014) Pathogenesis of gastric carcinoma in humans (Correa 1992) Examples in humans Barret s esophagus (Singh et al. 2013) Gastric carcinoma (Park & Kim 2015) Colorectal carcinoma (Rubin et al. 2007) 25.5.2017 4
Chromoendoscopy (CS) Outlines specific structures (Spillmann et al. 2014) Increases perception of mucosal detail Shows discrete changes 25.5.2017 5
Chromoendoscopy Principle Spraying the mucosa with color to enhance visualization Contrast enhancement Delineation of fine texture Specific staining 25.5.2017 6
Staining agents Absorbable (vital) stains Lugol (iodine) Glycogen (healthy squamous epithelium) Unstained inflamed / neoplastic tissue Methylene blue (MB) Absorptive intestinal epithelium (IM) Oxidative damage to DNA? Toluidine blue Mucopolysacharides (IM) Cresyl violet Crypts: patterns (Kudo et al. 2001) Cytoendoscopy (CFLEM) www.olympus-global.com 25.5.2017 7
Staining agents Non-absorbable stains Indigo carmine 0,2% Contrast enhancement Outlines superficial texture Reactive stains Acetic acid 1% Reversible -S S- acetylation Opacity Mucolysis Congestion Congo red + MB (double-staining) Phenol red + urea (map H. pylori) 25.5.2017 8
Esophagoscopy (human) Lugol High-grade dysplastic squamous epithelium Trivedi & Braden 2013 25.5.2017 9
Esophagoscopy (human) Acetic acid Horwhat, 2011 25.5.2017 10
Gastroscopic findings Belgian shepherd dogs Small polypoid change (2mm x 5mm) in antrum Histology: Severe chronic eosinophilic gastritis in antrum Mild to moderate findings in corpus Indigo carmine 0,2% 25.5.2017 11
Gastroscopic findings Belgian shepherd dogs Diffuse mucosal irregularity in distal gastric body Histology: Severe dysplasia and loss of mucosal neck cells in the glands Indigo carmine 0,2% 25.5.2017 12
Gastroscopic findings Belgian shepherd dogs Gross, diffuse mucosal irregularity in gastric body Histology: Chronic, diffuse neutrophilic gastritis with moderate, focal eosinophilic component Body (multifocal): severe edema, moderate eosinophilic infiltration, connective tissue surrounding glands Indigo carmine 0,2% 25.5.2017 13
Colonoscopy (human) Early detection of CRC in IBD / UC Identification of discrete changes and flat polyps Trivedi & Braden 2013 25.5.2017 14
Colonoscopy(human) Kudo pit pattern Cresyl violet 25.5.2017 15
Chromoendoscopy Preparation Excellent patient preparation is mandatory for enhanced mucosal visualization! Fasting Oral preparation solution Mucolytic (N-acetylcysteine) Antifoam (simethicone) Flushing + aspiration 25.5.2017 16
Chromoendoscopy Application Catheter 1-2cm out of endoscope tip Apply small amounts to avoid dye pooling Withdraw scope in spiral movements while spraying Stepwise spray and examine segments 25.5.2017 17
Curative endoscopic treatments Contrast enhancement Delineation of borders Endoscopic mucosal resection (EMR) Endoscopic submucosal dissection (ESD) Hazewinkel & Dekker 2011 Nonaka & Kita 2011 25.5.2017 18
Chromoendoscopy in dogs Summary Feasibility in small animal gastroenterology Easily performed, effective, cheap Diagnostic possibilities Detection of discrete mucosal changes Potential for increased diagnostic yield (targeted biopsy) Potential for demonstration of precursor lesions in GI cancer Therapeutic possibilities (diagnosis cure) Delimitation of borders Improved prognosis assessment Endoscopic removal of early precancerous lesions Endoscopic mucosal resection or submucosal dissection 25.5.2017 19
CS and NBI in dogs Acknowledgements University of Helsinki, Finland S. Kilpinen; T. Spillmann Small Animal Internal Medicine N. Airas; P. Syrjä Veterinary Pathology University of Liverpool, UK P.J. Noble Small Animal Gastroenterology Olympus Finland M. Lähdesmäki, A. Vallin Research Funds Brazil: National Counsel of Technological & Scientific Development (CNPq) Finland: DP-CVM, Finnish Foundation of Veterinary Research (SELS), Finnish Veterinary Foundation (ETTS), Dog Health Fund 20