Echoendoscopic characterization of the human colon

Abstract

Purpose: To characterize colon and rectum walls, pericolic and perirectal spaces, using endoscopic ultrasonography miniprobes.Methods: Sixty individuals (50% males), aged 18-80, were included. Using 12 and 20 MHz endoscopic ultrasonography miniprobes, all different colon segments (ascending, transverse, descending, sigmoid) and rectum were evaluated according to the number and thickness of the different layers in intestinal wall, to the presence and (largest) diameter of vessels in the submucosa and of peri-intestinal nodes.Results: The 20 MHz miniprobe identified a higher number of layers than the 12 MHz miniprobe, with medians of 7 and 5 respectively (p < 0.001). The rectal wall (p = 0.001), its muscularis propria (p < 0.001) and mucosa (p = 0.01) were significantly thicker than the different segments of the colon, which had no significant differences between them. Patients aged 41-60 presented thicker colonic wall and muscularis propria in descending (p = 0.001 and p = 0.004) and rectum (p=0.01 and p=0.01). Submucosal vessels were identified in 30% of individuals in descending and rectum, and in 12% in ascending. Adenopathies were observed in 9% of the colon segments and 5% in rectum.Conclusions: A higher frequency enabled the identification of a higher number of layers. Rectal wall is thicker than the one from all the segments of the colon and there are no differences between these, namely in the ascending colon. Moreover, periintestinal adenopathies were rarely identified but present in asymptomatic individuals. All together, these results describe for the first time features which are relevant during staging and therapeutic management of colonic lesions.

Tissue biomolecular and microstructure profiles in optical colorectal cancer delineation

“…Individual thicknesses of the tissue layers may have a wide range of thicknesses. According to Castro-Poças et al, mucosa layers can vary from 0.3 to 1.2 mm, submucosa can vary between 0.2 and 1.8 mm and muscularis propria can vary from 0.3 to 2.4 mm [100]. This variance may contribute to the heterogeneity of the biochemical and microstructural parameters obtained in the present study (table 2).…”

“…Even though it is possible to quantify the probed depth, specifying which tissue layers are being probed in the colorectal wall still remains a challenge. A typical thickness of the total wall is about 2 mm, which may also be changed by a number of factors [100]. Individual thicknesses of the tissue layers may have a wide range of thicknesses.…”

A Multilayer Monte Carlo Model for the Investigation of Optical Path and Penetration Depth at Different Perfusion States of the Colon

“…A multilayer colonic tissue model, consisting of four layers, was used as illustrated in Fig 1, where the mucosa is the inner most layer of the colon which progresses towards the outer surface known as the serosa. The optical properties and thickness for the colonic layers were found in the literature (Table I) [10], [11], [12], [13]. A homogenous mixture of mucosa and blood was assumed to model a perfused colonic tissue, where the volume fraction of blood, V , was characterized by the combination of absorption and scattering coefficients of oxyhemoglobin (HbO) and deoxyhemoglobin (Hb).…”

A new open door for endososcopic ultrasound (EUS); the colon

“…The study by Castro-Poças FM et al (11), published in this issue of The Spanish Journal of Gastroenterology is of real interest, since it provides with important information regarding the characteristics of the colon wall. Authors define the morphology, based on the EUS evaluation of the layers of the colon wall, at different sites, and by using different types of probes and miniprobes.…”

“…This limitation is clearly related to the lack of information regarding the possibility of performing a EUS of the colon, and to the lack of knowledge about the characteristics of the colon wall. First step to clarify this option has been provided by Castro-Poças FM et al (11).…”