We learn at a young age that blood plays a role in the health and function of the many parts of our bodies, from transporting nutrients to fighting infection to removing waste. Although the organ we most associate with blood is the heart, the relationship between blood and the brain is one of the most important — and can severely affect your health if there’s a problem.
Blood and the Brain
The brain requires a lot of blood — more than most parts of your body — to stay healthy. Blood brings oxygen and glucose (a form of sugar), which provide the energy the brain needs. Because the brain can’t store energy like muscle cells or organs (such as the liver), it requires a steady stream of this oxygen and glucose. In fact, the brain uses up to 20 percent of the body’s energy.
Blood reaches the brain through two pairs of main arteries along with a vast network of smaller vessels. Several factors can reduce the flow of blood to the brain, including:
- Arteriosclerosis. This is a hardened buildup of fat and cholesterol inside the arteries. When it occurs in the arteries of the neck, it’s called carotid artery disease. When it occurs in an artery inside the brain, it’s called intracranial artery stenosis. Many factors can lead to arteriosclerosis, including high levels of “bad” cholesterol, high blood pressure, smoking, diabetes, obesity, and lack of physical activity.
- Aneurysm. This is a bulging or ballooning of an artery wall. Sometimes the affected artery can’t be repaired with treatments such as endovascular coiling or surgical clipping. [link to aneurysm treatment page]
- Tumors in the brain. Some brain tumors are located so close to an artery bringing blood to the brain that the artery will be damaged when the tumor is removed.
- Moyamoya disease. This rare, progressive (gets worse over time) disorder is caused by blocked arteries at the base of the brain in an area called the basal ganglia. Though it can affect adults, it primarily affects children.
When your brain doesn’t get the blood it needs, the reduced oxygen can cause a stroke or a transient ischemic attack (TIA), which is a temporary shortage of blood flow to your brain also known as a “mini-stroke” and a potential warning sign of a future stroke.
Cerebrovascular Bypass for Blocked Arteries
In some cases, a slowed or blocked artery can be treated with a procedure to widen it. Two common procedures are angioplasty, where a tiny balloon is inserted into the artery and inflated, or inserting and expanding a metal mesh tube called a stent.
Your doctor will consider a cerebral artery bypass — where the artery is literally “bypassed” and blood follows a new path, in the same way, blocked heart arteries are bypassed with cardiac bypass surgery — when your condition is severe or (in the case of a brain tumor, for example) a balloon or stent isn’t a viable option.
Also known as an extra-cranial, intracranial (EC-IC) bypass, the procedure uses a small artery from the scalp or a vein from the leg to create a new path for blood to flow to the brain. Because the vessels are inside the skull, a procedure called a craniotomy [link to that page], which is the surgical removal of part of the skull, is required.
The surgery will be performed under anesthesia, meaning you will be asleep. After the craniotomy is performed, the surgeon will create a new path for blood to flow to the brain by using one of your existing vessels. Depending on the size of the affected artery, there are two vessel options:
- A large affected artery will likely be bypassed by a vessel graft, which uses part of a vein or artery from somewhere else in your body, often your arm or leg. This vessel is then connected above and below the blocked artery, and blood will flow around it.
- A smaller affected artery will usually be bypassed by a donor artery, which is a healthy artery in your face or scalp. The donor artery is detected from one end and reconnected to an artery that flows blood to the brain.
After your cerebrovascular bypass surgery, you’ll likely remain in the hospital for three to five days. It could be up to six weeks before you can return to your everyday activities.
Make an Appointment with Dr. Woodall Today
As an experienced and highly trained expert in procedures related to the brain, spinal cord, peripheral nerves, and vascular system — including cerebrovascular bypass — Dr. Woodall offers the latest advances in surgical neuroscience care. Contact our office today.