Lung vessels thrombosis in patients with lethal severe community-acquired pneumonia: electronic microscopies with 3D modeling

High lethality of hospitalized patients with CAP is well known fact, but risk factors of mortality including thrombosis had not been investigated to the end. Aim: to study microscopically changes in lung autopsy in patients who died because of severe CAP. Materials and Methods: electronic microscopy of lung tissue in 5 patients died because of severe CAP, 3-D computer modeling. Results: On autopsy macroscopically we found thrombosis of small or large branches of the pulmonary artery on the background of expressed purulent-destructive changes, microscopically – wall clots, partly with obturating growth, necrosis of surrounding tissues, lymphohystioid and neutrophil infiltration; the organization of the thrombus with the recanalization of the vessels. Histologic cut in the sagittal projection of branches of the pulmonary vein of the muscular type, enlargement of the endothelial lumen banding region, change of the nuclear-cytoplasmic ratio of endothelial cells; “wetting phenomenon”, adhesion of erythrocytes, macrophages; swelling intima. Three-dimensional models of the vessel corresponding to the cut. Bottom, side and top view. Conclusions: patients with CAP have thrombosis of lung vessels which differ from embolism or post-mortem blood clots. These changes reflect systemic thrombosis at patients with severe CAP and could be the reasons of increased mortality in this category of patients.