Real-Time Observation Of Microcirculatory Hemodynamics In Atrophic Gastritis By Probe-Confocal Laser Endomicroscopy

Aims To observe the differences of microcirculation among non-atrophic gastritis (NAG), atrophic gastritis (AG) and intestinal metaplasia (IM) using probe-confocal laser endomicroscopy (pCLE) in vivo.Methods Patients for endoscopic surveillance using pCLE were recruited. The microcirculatory hemodynamics and morphologies of gastric antrum were evaluated with pCLE among NAG, AG and IM. A semi-quantitative analysis containing subjective assessment is applied for the assessment of flow determination. Blood flow velocity was classified into seven grades:linear flow, linear particle flow, particle linear flow, particle flow, slowly particle flow, particle of pendulum flow and stagnation. The pCLE images were analyzed with Cellvizio Viewer software and Adobe Photoshop CS6 software. Ex vivo immunohistochemical (IHC) staining for CD34 was performed on targeted biopsy.Results A total of 109 patients (58 males and 51 females; average age 53.6 years, range from 22-80 years) were enrolled in this study. There were no statistical difference in gende (p=0.694), age (p>0.05),BMI (p>0.05) in the three groups. In NAG patients (n=49), the blood flow velocity were mainly linear flow (29.03%), linear particle flow (20.97%) and particle linear flow (20.97%). There were 11.29% slowly particle flow, but no particle of pendulum flow and stagnation. In AG patients (n=15), there was a similar type of blood flow velocity with that of NAG. It was mainly particle linear flow (23.08%), linear flow (26.92%) and linear particle flow (23.08%). There were 1.61% particle of pendulum flow, but no stagnation. In IM patients (n=45), there was a decline trend of the flow velocity which mainly present particle flow (26.92%), slowly particle flow (23.08%) and particle linear flow (25.64%). Several patients even appeared to be long or short particle of pendulum flow (8.98%) and stagnate (6.41%), of which the blood cells aggregated into a mass. Meanwhile, the line flow (2.56%) and line particle flow (6.41%) decreased. The microvascular area of IM was higher than those of AG (3750.70 vs.1864.97 um2, p=0.001) and NAG (3750.70 vs.2141.87 μm2,p<0.01). While the microvascular diameter of IM was larger than those of AG (14.41 vs.11.23 μm, p=0.001) and NAG (14.41 vs.12.17 μm, p<0.01). The features in IM appeared to be hypervascularity, dilatation and tortuosity in architecture. The results of IHC also shows that IM patients are of increased average vascular area than AG (p=0.012) and NAG (p=0.030) as well as a higher microvascular diameter than AG (p=0.009) and NAG (p=0.017).Conclusions This is the first study to demonstrate the semiquantitative assessment of microcirculation in the human gastrointestinal tract during pCLE endoscopy procedures. The results of microcirculation measured by pCLE has a good consistency with histology. Therefor, it might be a reliable tool for real-time assessment of microcirculatory hemodynamics in stomach. Low blood flow and increased microvessels may be an important aetiological factor in IM.