Evaluation of microvascular findings of deeply invasive colorectal cancer by endocytoscopy with narrow-band imaging

Abstract

Background and study aims: Magnifying narrow-band imaging (NBI) is useful for examination of colorectal lesions, and endocytoscopy (EC) allows diagnostic evaluation of structural atypia, nuclear atypia, and vascular structures of colorectal tumors. The aim of this study was to examine surface microvessels in deep invasive colorectal cancer using EC with a new NBI video processor system. Patients and methods: We retrospectively assessed 132 colorectal neoplastic lesions: 81 adenomas, 18 intramucosal cancers, 4 submucosal slightly invasive cancers, and 29 submucosal deep invasive cancers. Detailed vascular findings commonly seen in submucosal deep invasive carcinomas included > 2-fold vasodilatation seen in adenomas, abnormal tortuosity and branching, loss of the micro-network pattern, caliber change in > 2 places in a single blood vessel, and blood vessels not visible in a line because they appear like a string of beads (beaded sign). Results: Univariate analysis revealed 4 vascular findings that were strongly predictive of submucosal deep invasion: vasodilatation (odds ratio [OR] 9.31; 95 % confidence interval [CI] 3.57 – 24.30), loss of the micro-network pattern (OR 61.60; 95 % CI 17.87 – 212.29), caliber change (OR 35.7; 95 % CI 9.16 – 139.14), and the beaded sign (OR 45.90; 95 % CI 5.50 – 382.73). Conclusions: Detailed assessment of ultra-magnified microvessels could improve the diagnostic performance for submucosal deep invasive cancer. Study registration: UMIN-CTR000014033

Comparison of optical coherence tomography angiography and narrow-band imaging using a bimodal endoscope

“…26,27 OCT in combination with OCTA can in this situation provide a tool to distinguish between the different cancer stages by visualizing the LMM with its associated vasculature by OCTA while detecting the depth of the tumor with OCT. Several studies performed with NBI also in other organs stress the importance of visualizing the vasculature, as the structure is strongly altered in case of tumors due to the chaotic neovascular growth. 28 However, the contrast for deeper vasculature in the submucosa is critically reduced due to the stronger scattering and absorption at the short wavelengths of NBI and can only be accessed after peeling of superficial layers. 29 OCT and OCTA on the other hand operate at longer wavelengths and exhibit an efficient scattering suppression due to the combined confocal and coherence gating.…”

Ultra-magnifying narrow-band imaging for endoscopic diagnosis of gastric intestinal metaplasia: a pilot image analysis study

“…Some investigators have used contact ultra-magnifying NBI to diagnose diminutive colorectal polyps 20 , and invasive colorectal carcinoma 21 22 . However, in contact observation, NBI images are dark and coarse because the NBI light is dimmer than white light and the short wavelength light does not penetrate the mucosa well.…”

Endocytoscopy with NBI has the potential to correctly diagnose diminutive colorectal polyps that are difficult to diagnose using conventional NBI

“…A meshed capillary pattern is shown using magnifying NBI, whereas a MN pattern is shown using EC-NBI. The MN pattern is reportedly characteristic of adenomas [11,19]. We previously reported the endocytoscopic vascular (EC-V) pattern, which is classified as EC-V1 in hyperplastic polyps, EC-V2 in adenomas or intramucosal cancer, and EC-V3 in submucosal invasive cancer.…”