Sa1946 COLORECTAL ENDOCYTOSCOPY BASED MICROVESSELS OBSERVATION IS USEFUL FOR PREDICTING PATHOLOGICAL DIAGNOSIS

Abstract

Till now, narrowband imaging could make it possible to analyze the surface microvessels of colorectal lesions for differentiating neoplasms from non-neoplasms and for predicting the histropathological diagnosis. Endocytoscopy (EC) is the next generation of ultramagnification endoscopy that allow visualization of the glandular structure and cellular atypia. EC has visualized living tumor cells in vivo and obtained an ultra-magnification pathological image simply by applying the scope to the target mucosa during an endoscopic examination. However, in order to visualize cell nuclei, dye staining (i.e. methyleneblue) is always required. Since dye staining complicate the procedure, new observation method without use of dye has been strongly desired. On the other hands, EC with NBI (ECNBI) allows ultra-magnified microvessel observation without using any dye solution. The aim of this study was to validate the evidence whether the observation of surface microvessels using ECNBI was useful in predicting the histopathology of colorectal lesions. The study included 438 patients who underwent complete colonoscopy and endoscopic or surgical treatment between April 2006 and June 2015. A total of 576 lesions (45 Non neoplastic polyps, 304 adenomas, 71 intramucosal cancer, 21 slightly invasive submucosal cancer (SMs) and 135 massively invasive submucosal cancer. ) were retrospectively evaluated. We used the Kudo classification for the degree of submucosal invasion and classified cancers accordingly(1). SMs cancer without vessel permeation does not metastasize. In contrast, SMm lesions show a substantial proportion (∼10%) of lymph node metastasis. We named the ultra-magnified microvessel findings as endocytoscopic vascular (ECV) pattern and classified into the following 3 groups: EC-V1, the surface microvessels were very fine obscure; EC-V2, the surface microvessels were more clearly seen and showed a regular vessel network, and their caliber and arrangement were uniform; and EC-V3, the surface microvessels were thick, and their caliber and arrangement were non-homogeneous. The sensitivity, specificity and accuracy of EC-V1 for diagnosis of hyperplastic polyp were 88.9%, 98.5% and 97.7%, respectively. As regards the sensitivity, specificity and accuracy of EC-V3 for diagnosis of SMm were 82.2%, 97.7% and 93.8%, respectively Endocytoscopic vascular pattern was useful for predicting the histopathology of colorectal lesions.