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Visualization of the blood vessels in the brain of a patient without early venous filling, meaning without excessive reperfusion of the brain area after removal of the blood clot in the blocked artery. Image Credit: P. Thurner und Z. Kulcsar, USZ |
Blood vessels that cross-connect adjacent arterial trees regulate blood flow to the brain in stroke patients. Researchers at the University of Zurich have now shown that these vessels prevent brain hemorrhage following treatment to remove blood clots. They play a crucial role in the recovery of stroke patients.
Ischemic strokes are a major health burden. They occur when a blood vessel that supplies the brain becomes blocked, impairing blood flow to the brain. As a result, brain tissue suffers from a lack of oxygen and nutrients, which causes symptoms such as paralysis, confusion, dizziness, headache, trouble speaking or even death.
Many stroke patients recover poorly despite timely treatment
To treat these symptoms and restore blood flow to the brain, the obstructed vessel needs to be “declogged”, or recanalized. Contemporary treatments to remove the clot include intravenous thrombolysis or mechanical thrombectomy using a catheter. However, even with timely clot removal, many stroke patients only recover poorly.
The research group of Susanne Wegener, professor at the University of Zurich (UZH) and senior leading physician at the Department of Neurology of the University Hospital Zurich (USZ), has now demonstrated that the outcome of stroke treatments depends on the collateral network. Collaterals are blood vessels that cross-connect adjacent arterial trees, providing potential detour networks in case of a vascular blockage. “These vascular bridges maintain cerebral autoregulation and allow for a slower, gradual reperfusion, which results in smaller infarcts,” says Wegener.