Endovascular stroke treatment is a modern medical intervention that has transformed the approach to acute stroke care. This non-surgical procedure aims to remove blood clots from large vessels in the brain, significantly improving patient outcomes.
Understanding Ischemic Stroke
An ischemic stroke occurs when a blood clot obstructs blood flow to a region of the brain. This blockage deprives brain cells of oxygen and nutrients, causing them to begin dying within minutes. Ischemic strokes account for approximately 87% of all strokes and are considered life-threatening medical emergencies.
The rapid restoration of blood flow to the affected brain tissue is important to prevent irreversible damage and preserve brain function. Brain cells can die if deprived of blood for as little as 4.5 hours. Prompt diagnosis and treatment are therefore important, as every second counts in minimizing the potential for permanent brain damage and disability.
How Endovascular Treatment Works
Endovascular treatment, specifically mechanical thrombectomy, involves physically removing the blood clot. This process begins with the insertion of a thin tube, called a microcatheter, into an artery in the groin or arm. The physician then guides this catheter using X-ray imaging until it reaches the blocked blood vessel in the brain.
Once the catheter reaches the clot, various methods can be employed for removal. One common technique uses a stent retriever, a wire mesh device expanded within the clot to ensnare it. After a few minutes, the device is gently pulled back, retrieving the clot and re-establishing blood flow.
Another technique involves aspiration, where a large-bore catheter is advanced to the clot, and continuous suction is applied to remove the thrombus. Some procedures may combine both stent retrieval and aspiration. The primary goal of these interventions is to restore blood flow to the oxygen-starved brain tissue, aiming for full recanalization of the blocked vessel.
Who is a Candidate and Timing
Endovascular stroke treatment is for patients experiencing an acute ischemic stroke caused by a large vessel occlusion (LVO). LVOs involve blockages in major arteries supplying the brain, which often lead to more severe strokes. Eligibility for this procedure is determined through specific criteria, including the patient’s age and stroke severity, often assessed using scales like the National Institutes of Health Stroke Scale (NIHSS).
The timing of intervention is an important factor, with treatment recommended within 6 to 24 hours from when symptoms first appeared or the patient was last known to be well. This timeframe is often referred to as the “time window,” emphasizing the urgency of treatment to save brain tissue, a concept known as “time is brain.” Medical imaging, such as CT perfusion (CTP) or MRI, plays an important role in diagnosing the stroke and identifying patients who have salvageable brain tissue, even in extended time windows.
Advanced imaging helps determine the extent of brain damage and the amount of brain tissue that is still at risk but potentially recoverable, known as the “penumbra.” This imaging-based selection, rather than a strict time-based approach, allows for treatment in a broader range of patients. Endovascular therapy has demonstrated benefit for selected patients up to 24 hours from the last known well time, based on favorable imaging profiles.
After the Procedure
Following an endovascular stroke procedure, patients are closely monitored, typically in an intensive care unit. This monitoring includes regular neurological assessments and vital sign checks. The site where the catheter was inserted, usually the groin, is also checked for any bleeding or swelling.
The typical hospital stay after the procedure can vary, but endovascular thrombectomy can reduce the length of hospital stay, often to around 6.5 days. Following the acute hospital phase, rehabilitation is an important part of the recovery process.
Rehabilitation programs are tailored to individual needs, considering factors like the affected brain area and the degree of disability. These programs may involve physical therapy, occupational therapy, and speech therapy, with the goal of helping patients regain as much function as possible. While individual recovery varies, endovascular treatment has been shown to result in more favorable outcomes and improved quality of life.