Confocal Endomicroscope In-Vivo Three Dimensional Imaging And Esophageal Intraepithelial Neoplasia Diagnosis

Background and aimsLoss of surface maturation and cytonuclear atypia have been regarded as the pathological "golden standard" for the diagnosis of esophageal squamous cell intraepithelial neoplasia. However, there has been no satisfying confocal endomicroscopic method similar to such pathological approach to detect squamous surface maturation and screen for esophageal squamous cell intraepithelial neoplasia (ESIN). The aim of this study was to apply in-vivo three-dimensional confocal endomicroscopic imaging technique to investigate the characteristics of surface maturation of esophageal epithelium on plain confocal endomicroscopic images, and develop new confocal endomicroscopic criteria based on surface maturation.MethodsPart I:The in-vivo3D confocal imaging phase. Confocal endomicroscopic images were obtained at continuous depth on normal esophageal squamous epithelium, and then these image series were imported to Mimic10.0for three dimensional reconstruction. The ambient tissue of the reconstructed intrapapillary capillary loops (IPCLs) was set transparent to partially expose the reconstructed IPCL and demonstrate the stereo configuration of between IPCL and its surrounding esophageal epithelium. The novel surface maturation scoring (SMS) method for plane confocal images was developed based on the interpretation3D microstructure and surface maturation.Part Ⅱ:The clinical diagnostic phase. From May2008to April2010, consecutive outpatients with esophageal symptoms or due to screening endoscopy, or who were under surveillance of known intraepithelial neoplasia at Qilu Hospital underwent upper digestive tract confocal endomicroscopy after informed consents. White light endoscopy were firstly performed on all patients. Suspected lesions were examed by confocal endomicroscopy and biopsy samples were obtained for pathological examination. Confocal endomicroscopic images from all non-invasive lesions were randomly rearranged and blindly evaluated by two senior confocal endomicroscopists via SMS approach for the calculation of sensitivity, specificity, intra-and inter-observer agreement. Meanwhile, another senior investigator blindly evaluated these images via conventional IPCL and heterogeneous cell approach for diagnostic efficiency comparison.ResultsPhase I:We successfully obtained and interpreted the first in-vivo3D confocal image at human esophageal epithelium. Via the interpretation and analysis of the stero configuration between IPCL and plane confocal endomicroscopic images, four characteristics of surface maturation, the existence, gradient, polarity and compass effect around IPCL, were summarized. SMS was developed on the basis of these four characteristics.Phase II:A total of1214patient were screened and64of them was positive of non-invasive esophageal lesions. Histopathology showed21of the64lesions were ESIN, including9low grade intraepithelial neoplasia and12high grade ones. The other lesions include35inflammatory,7hyperplastic and1normal epithelium. Confocal images from these lesions were independently and blindly evaluated using SMS and previous methods. SMS=0had a diagnostic sensitivity of81.0%(95%CI:58.1-94.6%), a specificity of90.7%(95%CI:77.9-97.4%), a positive likelihood ratio of8.70, substantial inter-observer agreements (weighted κ value0.687,95%CI:0.530～0.844), and substantial intra-observer agreements (weighted κ value0.601, 95%CI:0.434-0.768). In comparison with conventional irregular IPCL morphology, SMS was superior in sensitivity (P<0.05) and (P<0.01) specificity. In comparison with heterogeneous cells, SMS was superior in sensitivity (P<0.05).Conclusions3D confocal endomicroscopic imaging provides unique insight into the stereo configuration of esophageal epithelium in human. The interpretation of stero-configuration at esophageal epithelium deepened our understanding of surface maturation, and led to improved diagnostic efficiency of esophageal epithelial squamous intraepithelial neoplasia via the newly developed SMS method. Surface maturation scoring is a novel and promising diagnostic method to distinguish neoplasia during ongoing endoscopy.SignificanceTo our knowledge, this is the first application of3D confocal imaging within human body using endomicroscope.3D endomicroscopic imaging is suited for studies of the organization of tumor microenvironment and angiogenesis within human hallow organs. Detailed3D information provided by endomicroscopic imaging may also support future non-invasive assessment of treatment effects during anti-angiogenic therapy in human. Endomicroscopic surface maturation scoring offers great promise for the early detection of esophageal squamous intraepithelial neoplasia, and this method has the potential to be generalized to many other squamous epithelium coating organs.