Modelling the effects of cerebral microthrombi on tissue oxygenation and cell death
Journal
Journal of Biomechanics
Journal Volume
127
Date Issued
2021
Author(s)
Abstract
Thrombectomy, the mechanical removal of a clot, is the most common way to treat ischaemic stroke with large vessel occlusions. However, perfusion cannot always be restored after such an intervention. It has been hypothesised that the absence of reperfusion is at least partially due to the clot fragments that block the downstream vessels. In this paper, we present a new way of quantifying the effects of cerebral microthrombi on oxygen transport to tissue in terms of hypoxia and ischaemia. The oxygen transport was simulated with the Green's function method on physiologically representative microvascular cubes, which was found independent of both microvascular geometry and length scale. The microthrombi occlusions were then simulated in the microvasculature, which were extravasated over time with a new thrombus extravasation model. The tissue hypoxic fraction was fitted as a sigmoidal function of vessel blockage fraction, which was then taken to be a function of time after the formation of microthrombi occlusions. A novel hypoxia-based 3-state cell death model was finally proposed to simulate the hypoxic tissue damage over time. Using the cell death model, the impact of a certain degree of microthrombi occlusions on tissue viability and microinfarct volume can be predicted over time. Quantifying the impact of microthrombi on oxygen transport and tissue death will play an important role in full brain models of ischaemic stroke and thrombectomy. ? 2021 Elsevier Ltd
Subjects
Cell death
Hypoxia
Oxygen transport
Stroke
Thrombus
Blood vessels
Oxygen
Physiological models
Tissue
Cell death model
Ischemic strokes
Mechanical
Microvascular
Thrombectomy
Tissue cells
Tissue oxygenation
brain ischemia
cell death
cerebrovascular accident
human
thrombectomy
thrombosis
Brain Ischemia
Cell Death
Humans
Thrombosis
Type
journal article