Introduction to Stroke

Every part of the body requires a steady supply of oxygen-rich blood for proper functioning. The brain is the second largest internal organ in the human body (after the liver) and weighs around 1.5 kg. It is an important member of the Central Nervous System and controls just about everything that we do in our life. Needless to say, the human brain needs a constant supply of oxygen-rich blood.

Any disruption in this blood-flow can lead to serious consequences. Those areas of the brain which are served by the blood-vessels where there is disruption cannot function normally. This condition is called stroke. If detected in the golden hour, and treated, the damage can be reversed. However, delays in providing emergency treatment can cause permanent disability. This includes paralysis or loss of function in one side of the body.

There are 3 types of Stroke:

• Ischemic stroke: Atherosclerosis is a condition in which cholesterol and certain other substances found in the blood can deposit in the inner walls of arteries, anywhere in the body, including the brain. The deposits cause stenosis or narrowing down of the artery, which gradually cuts off the blood supply. When there is total blockage, it results in a stroke attack. Similarly, blood-clots caused by pieces of plaque that break off and tear the wall of the blood-vessel triggers the formation of blood-clots. One or more clots can block the artery, which strops the blood-flow. This type of stroke is the most common, and is called Ischemic stroke.
• Haemorrhagic stroke: Aneurysm is a condition in which, the wall of the blood-vessel suddenly develops a balloon-like bulge. Blood rushes from the blood-vessel into the bulge, which then gets filled with blood. Over time, the pressure of blood inside the bulge is so high that it bursts, causing a haemorrhage or blood to leak inside the brain. That area of the brain which is supplied blood by this leaking blood-vessel now does not get adequate oxygen-rich blood, leading to a stroke attack. This type is called a Haemorrhagic stroke.
• Transient ischemic attack (TIA): Also known as a mini stroke, this is a miniature version of the first type – which is the Ischemic stroke. But this lasts less than 5 minutes. It is possible that the blockage due to plaque, or a blood-clots, clears up on its own after a few minutes. TIA may not cause the same kind of complications such as a full-blown ischemic stroke, but if it is not treated, it increases the risk of one.

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Also Read: Surgical Options for Brain Stroke

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Surgical interventions for treatment

Diagnosing the risk of stroke is done using CT scan, CTA scan, MRI scan, MRA scan and Doppler Sonography. Once diagnosed, medication can be given to flush out plaque deposits and blood clots. Diet and lifestyle changes can reduce the progression of atherosclerosis and even reverse it. In those cases, where medication, diet and lifestyle changes have not helped, or if the stroke risk was not even detected in the first place (due to health checkups not being done for long), a surgical intervention to is inevitable.

If the patient displays stroke symptoms suddenly, this should be treated as a stroke attack, and the patient must be rushed to a hospital immediately. Emergency treatment can reverse the stroke symptoms. If the golden hour has passed by and stroke symptoms have set in, surgical intervention is one of the treatment methods. Again, surgical intervention is of various types and includes:

• Intracranial bypass procedures: Similar to bypass procedures done for blocked arteries in the heart. A small section of artery and vein taken from another part of the body is used to create a loop around the blockage and bypass the blood-flow, thereby restoring blood-flow.
• Craniectomy and hemispheric decompression: This is done when a large area of the brain is affected. The haemorrhage in the brain causes blood to leak. Additionally, the injury can cause a build-up of cerebro-spinal fluid around the brain. This and the leaking blood put a lot of pressure on the brain. So, a procedure is done where the skull is cut open, some of the cerebrospinal fluid drained and the blood-leak plugged. Then the skull is sutured back.
• Carotid endarterectomy: The carotid artery which supplies blood to the brain and is located in the neck can develop atherosclerosis and increase stroke risk. So, an open surgical procedure will access this artery and help clean up the plaque. So also, aneurysms inside the brain are clipped, thereby preventing them from bursting which increases the risk for haemorrhagic stroke.
• Stereotactic radiosurgery: This is done to treat Arterio-Venous Malformations (AVMs) when they lie deep inside the brain and are hard to access.
• Endovascular surgery: This includes angioplasty and stenting. This is done to treat intracranial aneurysms, extracranial and intracranial obstructions and AVMs.

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Also Read: The Role of a Comprehensive Stroke Care Center

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Surgical interventions to prevent stroke

Can stroke be prevented, or its risk reduced? Definitely yes! A healthy diet and lifestyle can go a long way in preventing strokes. Additionally, an annual health checkup will show signs of atherosclerosis and other vascular conditions. In such a case, the doctor may try medication depending on the severity of the condition. But in some case, he/she may decide that surgery is inevitable to prevent stroke. This primarily includes the below procedures:

Carotid end-arterectomy (CEA)

CEA mentioned in the previous section can be done to both prevent a stroke attack and treat one, after an attack has occurred. This is an open-incisional procedure. As mentioned earlier, the carotid artery runs on both sides of the neck and supplies blood to the brain. Both the left, common-carotid-artery and the right, common-carotid-artery branch off from the aorta (main blood vessel taking oxygen-rich blood from the heart to rest of the body), travels through the chest into the neck, along the neck and enters the brain at its base.

Atherosclerosis can cause plaque deposits to block blood-flow in either of the carotid artery branches (right and left), or both in rare cases. Imaging scans can show where the blockage is and to what extent.

Once detected, the patient will have to undergo an open, incisional procedure under general anaesthesia. The surgeon will cut through the skin and other tissues in the neck, to access the carotid artery. Then, he/she will cut the artery and physically scrape off the plaque. Thereafter the artery and all the tissues above it are sutured up. The incision on the skin is stitched up. The wound will be cleaned regularly to prevent infection. The patient will stay in the hospital for a couple of days and once his/her vitals are stabilized, he/she will be discharged.

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Also Read: Life after a stroke: Recovery and Rehabilitation

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Carotid Artery Stenting (CAS): 

Some patients are not suitable for an open, incisional procedure like CEA. Age and existing health conditions can increase the risk of morbidity (illness) and mortality (death) when CEA is done on them. That is why, in such patients, a minimally invasive procedure such as balloon angioplasty with stenting is done to minimize the risk of stroke.

The procedure is very similar to what is done for coronary arteries in the heart. An endoscope is a thin, flexible tube that contains another tube running inside along its entire length, and carrying one or more instruments at its tip. A small cut is made on the groin and the endoscope inserted into a major artery there. The endoscope is gently pushed all the way to the concerned carotid artery (left or right).

Once the endoscope reaches the site of the blockage, a balloon located at the tip of the tube inside is inflated. This pushes the plaque deposits against the artery wall, thereby clearing the blockage. The balloon is enclosed in a wire-mesh called stent. After the balloon is deflated, the stent will stay there in place. It will prevent a repeat development of plaque deposits there (over time, the inner-lining tissue will grow around the stent and stabilize its position). Then the balloon is deflated and the endoscope slowly pulled out of the body.

The procedure is done under local anaesthesia and the patient can be discharged the same day or the next day when his/her vitals have stabilized.

Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai (Alwarpet & Vadapalani), Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.

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