Disease of the chest portion of the largest artery in the body (the aorta) is known as thoracic aortic disease (TAD). The number of people experiencing TAD is increasing, and the rate at which TAD is being treated with a surgical procedure has risen sharply. Thoracic endovascular aortic stenting (TEVAR) is the preferred method of treating TAD. TEVAR is a minimally invasive procedure which results in reduced deaths (mortality) and complications (morbidity), compared to treatment of TAD with open surgical repair methods. TEVAR works by inserting and opening a metal mesh (a stent) in the diseased aorta, which re-lines it and opens it up, allowing blood to flow properly to the rest of the body.
However, stroke stills remains a real risk when using the TEVAR procedure. Up to 10% of TEVAR patients will experience a major stroke as a result of the procedure, and 70% of patients experience a silent stroke, known as a silent cerebral infarction (SCI). SCI is a brain injury that can only be detected on magnetic resonance imaging (MRI) brain scanning and is associated with a two to four-fold increased risk of a major stroke, depression, and cognitive decline (which may or may not lead to dementia).
The key risk factor for stroke during the TEVAR procedure (through manipulation of the stent in the aorta) has been identified as cerebral embolisation, which is when an artery in the brain becomes blocked, for example, by a blood clot.
A cerebral embolic protection device (CEPD) is a new technology. It protects the brain during the TEVAR procedure through the deployment of ‘filters’ in the arteries which supply the brain. These can capture emboli (which can cause a blockage) during the stenting treatment.
This device has been used successfully in patients undergoing heart valve repair and has been shown to reduce brain injury and improve cognitive outcome.
This is the first study to assess how feasible and effective CEPD devices are in patients undergoing the TEVAR procedure to reduce brain injury.
All patients undergoing the TEVAR procedure who are suitable for a CEPD will be recruited over an 18-month period. Patients will undergo MRI brain scanning before and after the operation. They will undergo a neurocognitive assessment immediately before, after and six weeks after the operation. Patients will also undergo ultrasound monitoring of the arteries to the brain. External monitoring and safety data for the device will be recorded.
All material captured in the filters of the CEPD device will be sent for microscopic examination to offer more information about their cause (histopathological analysis).
A reduction in strokes and resulting brain injury is expected from the TEVAR procedure when using a CEPD device. This will be determined from the results of the MRI brain scanning and by an objective assessment of patients’ cognitive function by a clinician.