Probe-based Confocal Laser Endomicroscopy For In Vivo Detection Of Microcirculatory Dynamics In Ulcerative Colitis

Background&Objective:Ulcerative colitis(UC) is increasing in both incidence and prevalence in recent years. UC is characterized by a relapsing and remitting course. The diagnosis of UC is based on a combination of clinical, endoscopic and histological features and the exclusion of an infectious etiology. Its pathophysiology is not clear, and the previous studies have focused on the history observation of epithelial cells and immune cells. Some studies indicate that UC has a higher risk of thrombosis, what’s more, human intestinal microvessels from chronically inflamed IBD show microvascular endothelial dysfunction, characterized by loss of NO-dependent dilation, which suggests that the microcirculatory dynamics may be abnormal in UC. The probe-based confocal laser endomicroscopy (pCLE) combines the superiority of endoscopy and histology and obtains dynamic images of mucosa and submucosa, so we can observe the changes of microcirculatory dynamics in vivo. But the detection of microcirculatory dynamics in vivo is still unknown. The aim of this article is to detect the changes of microcirculatory dynamics in vivo by pCLE and discuss the correlation between microcirculatory dynamics and inflammatory state, and provide clinical theoretical basis for pathophysiological research of UC.Method:42patients with UC (experimental group) and39patients without any abnormal findings in high definition endoscopic examination (control group) were enrolled in this study from March2013to March2014. All examinations were performed by one of four experienced gastroenterologists at CLE. All patients were given intravenous injections of lml of2%sodium fluorescein for an allergy test before the procedures. After intubation into the terminal ileum,3ml of10%fluorescein sodium was injected intravenously, then obtain pCLE images by contacting mucosa with appropriate pressure. In each patients of UC, the pCLE images were obtained from the terminal ileum and the worst lesions. While in control patients, the images are from the terminal ileum and the junction of sigmoid colon and rectum. Each image was recorded two static statistics (diameter and area) and four dynamic statistics (stagnate, wander, cluster and Cord-like money erythrocyte). The mayo clinical score and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) as the evaluation criteria of clinical and endoscopic manifestation respectively, and assess Inflammation Activity Classification by CLE. Compare the changes of microcirculatory dynamics of UC and the relevance between dynamic statistics and static statistics, clinical score, UCEIS, CLE classification.Result:The dynamic score of terminal ileum between UC and control group doesn’t show significant difference, while the dynamic score, microvascular dimeter and microvascular area of the lesions in UC patients are different from control group obviously, p<0.01. The relevance between mayo clinical score and UCEIS is significant (r=0.402, p<0.01), and the relevance between UCEIS and CLE classification is also significant (r=0.444, p<0.01).The dynamic score of lesion is significantly positive correlation with the UCEIS (r=0.395, p<0.05). The correlation coefficient of "stagnate, wander, cluster and Cord-like money erythrocyte" and UCEIS is0.039,0.445,0.187and0.121respectively.Conclusion:The probe-based confocal laser endomicroscopy can observe microcirculatory dynamics of UC in vivo. The diameter and area of intestinal mucosa microvessel increase at lesions of Ulcerative colitis, but the blood flow has the obvious trend of stasis, which is significantly relevant to inflammatory state. The severer inflammation is, the slower of blood flow, and the higher risk of thrombosis.