 | Cerebral Aneurysm |
What is an aneurysm?
An aneurysm is an abnormal bulging of a vessel wall that can involve all walls (fusiform), a sac arising from one wall (saccular) or a separation of the vessel walls (dissecting). An aneurysm can affect any vessel in the body, but only those in the head can cause a bleeding stroke when they rupture. If a brain aneurysm ruptures, the resulting bleeding can cause hemorrhagic stroke, brain damage and death. Approximately six percent of the population has a cerebral aneurysm. About 30,000 cases of bleeding in the United States each year result from ruptured aneurysms. Aneurysms are usually acquired, occur in people 40 to 60 years old and are slightly more common in women. What happens if an aneurysm ruptures?Most patients have no symptoms until an aneurysm ruptures. Occasionally, if an aneurysm is large or in a strategic location, the patient may complain of headaches, vision changes or other neurological problems. When an aneurysm ruptures it causes bleeding into the spaces around the brain (subarachnoid spaces). This causes patients to experience an extremely painful headache and is a medical emergency. Approximately 10 to 15 percent of patients who suffer a ruptured brain aneurysm die before reaching the hospital. About half of such patients die within the first thirty days of bleeding. Of the remaining survivors, about half remain dependant on others for normal activities of daily living. Patients with aneurysmal subarachnoid hemorrhage may spend up to two weeks in the intensive care unit (ICU). These patients can experience complications from hydrocephalus and vasospasm. Hydrocephalus is swelling of the fluid spaces in the brain and can require a drainage tube. Hydrocephalus is a spasm or narrowing down of the vessels of the brain that reduces the blood flow. This can be prevented in the ICU with medication that dilates the vessels or increase the pressure in the vessels. Sometimes these medications may not be enough to treat the spasm, and more aggressive management is required, such as directly injecting vasodilator medications into the brain blood vessels or using a balloon to open up the vessels. How is an aneurysm diagnosed?Typically the first step in diagnosing a suspected unruptured aneurysm is to undergo CT scan or MR angiogram of the head. These are noninvasive methods a radiologist uses to look at the blood vessels in the head. A physician will determine which is the better option for each patient. MR does not involve radiation or contrast risks, while a CT produces better resolution and is better for operative planning. Patients suspected of having a ruptured aneurysm typically undergo a CT scan of the head and a CT angiogram, which shows subarachnoid hemorrhage and the aneurysm. While CT and MR can show many aneurysms, most patients with aneurysms need a cerebral angiogram for definitive diagnosis and to determine the best treatment. An angiogram is an invasive procedure during which a neuro-interventional surgeon guides a flexible tube (catheter) through an artery over the hip to the vessels of the brain. A liquid dye or contrast agent is injected into the vessel, and pictures are taken with a fluoroscope. An angiogram gives the highest detailed pictures of the location, size and shape of the aneurysm. All of this information is used to develop the best treatment option for each patient.  | Aneurysm clipping |
How are aneurysms treated?Aneurysms can be treated from outside the blood vessels (open surgery) or from inside the blood vessels (endovascular surgery). Open surgery requires creating an opening, or window, in the skull and gently dissecting through the brain to get to the aneurysm. A surgeon places a clip across the aneurysm where it arises from the blood vessel. This prevents blood flow from entering the aneurysm. Aneurysm coiling is a neuro-interventional treatment for brain aneurysm. Endovascular surgery is performed using tiny catheters. One approach is to thread platinum coils into the aneurysm until it is completely blocked off from blood flow, which blocks it entering the aneurysm. Additional devices, such as a stent or a balloon, may be needed to help keep the coils in place inside the aneurysm. Stent assisted coiling involves permanently placing a stent in the vessel adjacent to the aneurysm to provide a scaffolding of support that keeps the coils within the aneurysm sac. Balloon remodeling involves temporarily placing a removable balloon adjacent to the aneurysm while coils are positioned in the aneurysm.
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