Cresyl violet as a new contrast agent in probe‐based confocal laser endomicroscopy for in vivo diagnosis of gastric intestinal metaplasia

Abstract

Background and Aim Cresyl violet (CV) is a topical dye that allows simultaneous chromoendoscopy and in vivo confocal laser endomicroscopy in identification of neoplastic changes of the lower gastrointestinal tract without intravenous injection of fluorescein, but as yet no investigation has reported its application in the diagnosis of gastric intestinal metaplasia (GIM). This study aims to assess the feasibility as well as diagnosis accuracy of topical CV for in vivo diagnosis of GIM by using probe‐based confocal laser endomicroscopy (pCLE). Methods In this prospective, open‐label, feasibility study, 129 confocal videos from 22 patients with known GIM were analyzed and compared with corresponding histological images to establish the CV staining characteristics. In addition, 47 patients with known or suspected GIM were prospectively enrolled to evaluate the accuracy of this topical CV endomicroscopic imaging. Results Probe‐based confocal laser endomicroscopy with topical CV enabled clear visualization of the goblet cells, absorptive cells, and intestinal villi of GIM. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of pCLE diagnosis of GIM on a per‐location analysis was 93.01%, 91.95%, 93.51%, 86.96%, and 96.11%, respectively. The intraclass correlation coefficient for inter‐observer agreement and mean kappa value for intra‐observer agreement for the diagnosis of GIM was 0.82 and 0.87, respectively. Conclusions Topical CV enables real‐time chromoendoscopy in conjunction with pCLE examination of the stomach and warrants accurate diagnosis of GIM. It may be an acceptable and potentially alternative dye for confocal imaging in the future.

Visualization of the human enteric nervous system by confocal laser endomicroscopy in Hirschsprung's disease: An alternative to intraoperative histopathological diagnosis?

“…Another major limitation of a broader application of CLE in assessing the ENS in a clinical setting is the current lack of a fluorescent dye with a high affinity to neural tissues that is also approved for human use. Cresyl violet has been used empirically for chromoendoscopy and clinically as a fluorescent contrast agent in CLE for many years with no reports of adverse effects so far . However, the safety profile of the substance, including possible mutagenicity, needs to be carefully assessed for long‐term use.…”

“…Confocal laser endomicroscopy (CLE) allows real‐time, in vivo characterization of architectural and cellular details of tissue and is widely accepted as a tool for use in optical biopsies where it enables histological analysis not only of malignant tumors but also of benign diseases requiring pathological diagnosis, such as inflammatory bowel diseases, during a routine endoscopy without the need for actual tissue sampling. Our group demonstrated the technical feasibility of visualizing the ENS using CLE within a submucosal space created for the purpose after topical application of neural fluorescent molecular probes in animal models in vivo and in humans .…”

Visualization of the human enteric nervous system by probe confocal laser endomicroscopy: a first real-time observation of Hirschsprung’s disease and allied disorders

“…CV has been used widely in the histopathology lab for Nissl staining [ 7 ] or as a lysosomal marker [ 8 ]. Moreover, it has been used clinically for chromoendoscopies in Japan since the 1980’s and has an established safety profile [ 9 – 13 ]. CV has an emission and excitation wavelength of 630 and 585 nm, respectively [ 8 ], which the CLE device used in the present study can detect.…”

Visualization of the Human Enteric Nervous System by Probe Confocal Laser Endomicroscopy: A First Real Time Observation of Hirschsprung’s Disease and Allied Disorders.

“…CV has been used widely in the histopathology lab for Nissl staining 7 or as a lysosomal marker 8 . Moreover, it has been used clinically for chromoendoscopies in Japan since the 1980's and has an established safety pro le [9][10][11][12][13] . CV has an emission and excitation wavelength of 630 and 585 nm, respectively 8 , which the CLE device used in the present study can detect.…”