Surgery for stroke technically falls into the prevention category, but is covered here because it is surgical in nature.
Two conditions in the arteries that lead to the brain can predispose you to stroke. Both are the result of
atherosclerosis
(fatty deposits in the arteries), which can lead to:
- Narrowing of an artery that will eventually shut off the blood supply to the brain altogether
- Ulceration of a fatty deposit (plaque) that makes it likely to break off and obstruct the artery further down stream
Surgery attempts to correct either or both events. Very careful evaluation is required to determine which lesions will benefit from surgery.
A narrow area of your artery, usually the carotid artery, can be bypassed by sewing in a replacement tube above and below the obstruction.
This surgery is nearly always done on the carotid arteries, which lie on either side of your windpipe. It may also be done between a scalp artery and a vessel inside your skull.
After attaching you to monitoring devices in the surgical suite, you will be under general anesthesia. The surgeon will cut the skin over the involved artery or arteries, remove a piece of your skull if necessary, and sew a piece of tubing (Dacron or a vein that has been taken from your leg) between a healthy artery and the diseased one. The bypass may simply go around a short narrowed segment of a carotid artery, or it may connect an artery inside the skull with one from outside the skull.
The inner lining of these arteries is thickened and irregular and may contain deposits of calcium, but the outer layers may be healthy.
Very similar to an arterial bypass (and requiring that a bypass be used temporarily during the surgery), an endarterectomy simply carves out the inner lining, leaving behind the outer layers to carry the blood. There are technical reasons why one procedure is preferred over the other in any given individual. Endarterectomies are performed much more commonly than arterial bypasses for atherosclerotic disease of the carotid arteries.
Aneurysms are weak spots in arteries that balloon out and may rupture, allowing blood at high pressure to pump into neighboring tissues. It is sometimes possible to repair an aneurysm before it causes a major hemorrhagic stroke. An enlarging aneurysm may produce pressure in the brain before it ruptures. Or, it may leak slowly enough to allow detection and repair before the major bleeding begins.
Brain aneurysm surgery is brain surgery, with all the meticulous care and technology directed at safe, effective results. The goal is removal of a small weak spot on a blood vessel. Once visualized, the standard procedure is to clamp a small metal clip around the base of the aneurysm.
There are high-tech alternatives that can be accomplished without surgically entering the skull. Aneurysms are connected to the circulation and can be approached through blood vessels by threading long, thin catheters (tiny tubes) into them. It may then be possible to block the aneurysm from inside, perhaps by inserting metal coils or squirting them full of tiny beads that will cause a clot to form and scar them down.
A tiny, flexible tube (catheter) is threaded through the blood vessels and into the carotid artery or (less commonly) another artery in the brain. A balloon is introduced through the catheter and inflated within the blood vessel, in an effort to widen the blood vessel and improve blood flow through it. A stent (a mesh tube) is often left within the artery to keep it as open as possible. A mesh screen may be placed within the artery to catch any bits of plaque or clots that might otherwise flow upward into the brain.
Recently, a study was conducted comparing endarterectomy and stenting in 527 patients who recently suffered a minor stroke or TIA and had severe carotid artery narrowing (at least 60%). Even though endarterectomy is more invasive (and dangerous) than stenting, endarterectomy led to fewer deaths and repeat strokes than stenting within the first six months.
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A tiny, flexible tube (catheter) is threaded through the blood vessels until it reaches an area in the brain where a clot is lodged. Efforts are made to remove the clot through the catheter; or, clot-busting agents are administered through the catheter to the location of the actual clot.
Occasionally, a large stroke can lead to significant brain swelling. When this happens and medicines are not successful in relieving the swelling, a surgical intervention may be required to prevent the pressure buildup within the skull from causing further damage to the brain. In this procedure, the surgeon may temporarily open a flap of bone overlaying the swelling in order to alleviate the pressure. If the stroke is of the hemorrhagic type (bleeding), the blood clot may also be removed to prevent further brain injury.
