Innovative Diagnostic Endoscopy in Inflammatory Bowel Diseases: From High-Definition to Molecular Endoscopy

Abstract

High-definition endoscopy is one essential step in the initial diagnosis of inflammatory bowel disease (IBD) characterizing the extent and severity of inflammation, as well as discriminating ulcerative colitis (UC) from Crohn's disease (CD). Following general recommendations and national guidelines, individual risk stratification should define the appropriate surveillance strategy, biopsy protocol and frequency of endoscopies. Beside high-definition videoendoscopy the application of dyes applied via a spraying catheter is of additional diagnostic value with a higher detection rate of intraepithelial neoplasia (IEN). Virtual chromoendoscopy techniques (NBI, FICE, I-scan, BLI) should not be recommended as a single surveillance strategy in IBD, although newer data suggest a higher comparability to dye-based chromoendoscopy than previously assumed. First results of oral methylene blue formulation are promising for improving the acceptance rate of classical chromoendoscopy. Confocal laser endomicroscopy (CLE) is still an experimental but highly innovative endoscopic procedure with the potential to contribute to the detection of dysplastic lesions. Molecular endoscopy in IBD has taken application of CLE to a higher level and allows topical application of labeled probes, mainly antibodies, against specific target structures expressed in the tissue to predict response or failure to biological therapies. First pre-clinical and in vivo data from label-free multiphoton microscopy (MPM) are now available to characterize mucosal and submucosal inflammation on endoscopy in more detail. These new techniques now have opened the door to individualized and highly specific molecular imaging in IBD in the future and pave the path to personalized medicine approaches. The quality of evidence was stated according to the Oxford Center of evidence-based medicine (March 2009). For this review a Medline search up to January 2021 was performed using the words “inflammatory bowel disease,” “ulcerative colitis,” “crohn's disease,” “chromoendoscopy,” “high-definition endoscopy,” “confocal laser endomicroscopy,” “confocal laser microscopy,” “molecular imaging,” “multiphoton microscopy.”

Colorectal Cancer in Ulcerative Colitis: Mechanisms, Surveillance and Chemoprevention

“…Still, it is difficult to accurately diagnose intraepithelial neoplasia (IN) in UC accurately because of lacking cellular resolution and subsurface imaging. Confocal laser endomicroscopy (CLE) and endocytoscopy (EC) are promising tools that enable the acquisition of microstructural objects (e.g., capillaries, villiform structure, crypt, goblet, or epithelial cells, nucleus and cytoplasm), representing that endoscopy will shift from macro to micro, and from surface to deep [ 141 ]. As early as 2007, several studies have indicated that CLE could increase the diagnostic yield of INs in UC patients [ 142 ], which was later reported in 2008 [ 143 ].…”

Inflammatory Bowel Disease and Colorectal Cancer

“…62 Endoscopic technology, artificial intelligence, and deep learning have the potential to revolutionize our surveillance further and some iterations of these are already in the clinical arena. 45,63 Funding None.…”

New endoscopic tools in inflammatory bowel disease

“…In IBD, CLE was used for structural and functional assessment of the intestinal epithelium, characterisation and classification of inflammatory activity and mucosal healing (MH) in active disease, dysplasia detection and molecular imaging for precision medicine. 3,34,35 The assessment of MH in IBD was a further application of CLE since it could accurately distinguish between patch/mild inflammation and MH.…”

“…In IBD, CLE was used for structural and functional assessment of the intestinal epithelium, characterisation and classification of inflammatory activity and mucosal healing (MH) in active disease, dysplasia detection and molecular imaging for precision medicine. 3 , 34 , 35 …”