Aneurysms

An aneurysm is a bulge in the wall of a weakened blood vessel. Think of a tire that has hit something hard and the wall is bulging and you have an idea of what an aneurysm looks like. An aneurysm can develop slowly over years as a blood vessel weakens or it can happen suddenly as the result of an injury. Aneurysms are dangerous because they can burst. If they do, it can lead to excessive bleeding and even death. They can happen anywhere in the body.

You can watch our ANIMATION to see how an aneurysm can happen. Below you'll find information on two dangerous types of aneurysms: aortic and cerebral.

Aortic aneurysms

Aortic aneurysms occur in the aorta, which is the large artery that leads away from our heart. (Read about the aorta in "The Heart and Cardiovascular System" and "The Vascular System") Aortic aneurysms can be classified by their location:

• Abdominal aortic aneurysms - The American Heart Association (AHA) says the more common aortic aneurysm is abdominal. It occurs in the lower part of the aorta, below the diaphragm.
• Thoracic aortic aneurysms - These are aortic aneurysms that occur in the chest cavity.

AHA says disease can cause a weakening or degeneration in the walls of the aorta. One common cause of degenerative aneurysms is atherosclerosis. (Read about "Arteriosclerosis & Atherosclerosis") Atherosclerosis is the result of the buildup of fatty material along a blood vessel. Aortic aneurysms can also be the result of other conditions such as Marfan syndrome. (Read about "Marfan Syndrome") People with Marfan face a greater risk of a certain type of aneurysm called dissecting where the wall of the artery tears lengthwise.

Some of the other risk factors, according to Aneurysm Outreach (AO) include:

• family history (Read about "Family Health History")
• smoking (Read about "Quit Smoking")
• high blood pressure (Read about "Hypertension: High Blood Pressure")
• high cholesterol (Read about "Cholesterol"
• trauma

Aneurysms develop in all groups but are ranked in the top ten causes of death for white males over 55.

Many times aneurysms will not have any symptoms. Sometimes, according to AHA, there will be some pain in the area. Some patients experience flank pain, similar to that of a kidney stone (Read about "Kidney Stones") or even a strained back muscle, as an early symptom of an abdominal aortic aneurysm. AO says sometimes the first sign is a pulsing mass in the abdomen.

A less common type of aneurysm, called aortic dissection, can produce symptoms that include stabbing or ripping chest pain. This is a potentially life-threatening condition in which there is bleeding into and along the wall of the aorta. It's a medical emergency that requires immediate treatment.

Detecting an aneurysm isn't all that difficult, with the right equipment. Many scanning techniques can be used including ultrasound and CAT scans, according to AHA. (Read about "Ultrasound Imaging" "CT Scan - Computerized Tomography")

Smaller aneurysms may be treated with "watchful waiting," along with lifestyle changes. Treatment of larger aneurysms often involves some sort of surgery. Traditional open surgery involves removal of the damaged section of the aorta, which is then replaced with a synthetic tube or graft. Less invasive endovascular aneurysm repair is another option. In this type of endovascular surgery, a thin tube or catheter is inserted through an artery in the groin and threaded up to the aorta. The catheter puts a synthetic graft and stent at the site of the aneurysm. According to the Food and Drug Administration, this provides a pathway so that blood can flow through the aorta. Blood flows through the graft without filling the aneurysm, thereby reducing pressure on the aneurysm with the intent of preventing it from bursting. AO says such procedures are generally successful. Surviving a ruptured aneurysm however is a lot less likely. Following treatment for any type of aneurysm, it is also essential to get any risk factors, such as high cholesterol or high blood pressure, under control.

Cerebral aneurysms

Cerebral aneurysm is a cerebrovascular disorder caused by a weakness in the wall of an artery in the brain. (Read about "The Brain") The disorder may result from congenital defects (Read about "Birth Defects") or from preexisting conditions such as hypertensive vascular disease and atherosclerosis (Read about "Arteriosclerosis & Atherosclerosis"), or from head trauma. (Read about "Head Injury") The National Institute of Neurological Disorders and Stroke (NINDS) says cerebral aneurysms occur more commonly in adults than in children and are slightly more common in women than in men; however they may occur at any age.

Rupture of a cerebral aneurysm is dangerous and usually results in bleeding in the brain or in the area surrounding the brain, leading to an intracranial hematoma (a mass of blood - usually clotted - within the skull). Rebleeding, hydrocephalus (the excessive accumulation of cerebrospinal fluid), vasospasm (spasm of the blood vessels), or multiple aneurysms may also occur. (Read about "Hydrocephalus") The American Stroke Association says a ruptured aneurysm in the brain can also be the cause of a stroke. (Read about "Stroke")

Onset is usually sudden and without warning, according to NINDS. The Brain Aneurysm Foundation (BAF) says that before an aneurysm ruptures, about 40 percent of individuals may experience such symptoms as:

• a sudden and usually severe headache
• nausea
• vision impairment
• vomiting
• loss of consciousness

The rest of the time the individual may be asymptomatic, experiencing no symptoms at all.

If your doctor suspects that you have an aneurysm, he or she may perform a computed tomography angiogram (CTA) which is a special CT scan of your brain. (Read about "CT Scan - Computerized Tomography") Another test that can be used is Magnetic Resonance Angiogram (MRA), which is a type of MRI of the brain. (Read about "MRI - Magnetic Resonance Imaging") If test results are normal, your doctor may still recommend that a spinal tap be performed to help with the diagnosis.

Not all cerebral aneurysms burst. According to NINDS, considerations for treating an unruptured aneurysm include the type, size and location of the aneurysm, as well as the patient's age, health, and personal and family medical history. The risks and benefits of treatment must also be compared to the risk of rupture. Options for treating cerebral aneurysms include microvascular clipping (which involves cutting off the flow of blood to the aneurysm), occlusion (the surgeon clamps off the artery that leads to the aneurysm) and endovascular embolization (a catheter is inserted into an artery and threaded to the aneurysm site, where it places material to fill the aneurysm and block it from circulation).

Emergency treatment for individuals with a ruptured cerebral aneurysm generally includes restoring deteriorating respiration and reducing intracranial pressure. Surgery is usually performed within the first 3 days to clip the ruptured aneurysm and to reduce the risk of rebleeding. (Read about "Neurosurgery") In patients for whom surgery is considered too risky, microcoil thrombosis or balloon embolization may be performed. Other treatments may include bed rest and/or drug therapy, according to NINDS.

The prognosis for a patient with a ruptured cerebral aneurysm depends on the extent and location of the aneurysm, the person's age, general health and neurological condition. Some individuals with a ruptured cerebral aneurysm die from the initial bleeding. Other individuals with cerebral aneurysm recover with little or no neurological deficit. Early diagnosis and treatment are important. Following treatment, it is also essential to get any risk factors, such as high cholesterol or high blood pressure, under control.

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