Patologìâ (Aug 2020)
Pathomorphological changes of the vascular bed and the state of collateral blood flow in cerebral infarction
Abstract
The aim of the study. To study the pathomorphological changes of the vascular bed and the state of collateral blood flow in cerebral infarction. Materials and methods. The brains of 45 deceased patients with hemispheric infarctions with different terms of the disease were studied during the work. The comparison group consisted of 10 patients who died suddenly from acute coronary insufficiency, who did not have diseases of the nervous system. To assess the morpho-functional state of blood vessels and the intensity of blood flow the cross-sectional area of blood vessels, the area of endothelial cell nuclei, the density of their location and the length of the capillary network were determined. Results. In the early stages of stroke, along with the processes of irreversible damage of small capillaries in the area of infarction and partly in the area of the penumbra, myocardial thrombosis and constant number of vessels in the perifocal area of infarction, there are processes aimed at providing effective blood flow in ischemic areas of brain by increasing collateral blood flow from the leptomeningeal vessels, increasing the diameter of blood vessels and the length of the capillary network. On the 6th day of the disease, the processes of collagenization of the subarachnoid space are registered, which reduced the collateral blood flow from the pial vessels to the underlying cortical parts of the brain. With the increasing of the disease duration, the diameter of the capillaries returns to initial values, in the perifocal areas of the infarct there is a recalibration of the lumen of the arterioles with a decrease in the total cross-sectional area of newly formed vessels, a significant number of arterioles with obliteration of the lumen are present. Conclusions. In the early stages of ischemic stroke there is an increase in blood circulation due to an increase in the diameter of the capillaries, the length of the capillary network and increased collateral circulation by the pial vessels. In the long-term period there is a reduction in the total area of the lumen of arterioles and a decrease in the efficiency of collateral blood flow, which should be regarded as an adaptive response of the vascular bed to decreased need for blood supply to stroke areas at the stage of cyst formation.
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