Aneurysm
An aneurysm (AN-u-rism) is an abnormal bulge or “ballooning” in the wall of an artery. Arteries are blood vessels that carry oxygen-rich blood from the heart to other parts of the body. An aneurysm that grows and becomes large enough can burst, causing dangerous, often fatal, bleeding inside the body.
Most aneurysms occur in the aorta. The aorta is the main artery that carries blood from the heart to the rest of the body. The aorta comes out from the left ventricle (VEN-trih-kul) of the heart and travels through the chest and abdomen. An aneurysm that occurs in the aorta in the chest is called a thoracic (tho-RAS-ik) aortic aneurysm. An aneurysm that occurs in the aorta in the abdomen is called an abdominal aortic aneurysm.
Aneurysms also can occur in arteries in the brain, heart, intestine, neck, spleen, back of the knees and thighs, and in other parts of the body. If an aneurysm in the brain bursts, it causes a stroke.
When found in time, aneurysms can usually be treated successfully with medicines or surgery. If an aortic aneurysm is found, the doctor may prescribe medicine to reduce the heart rate and blood pressure. This can reduce the risk of rupture.
Large aortic aneurysms, if found in time, can often be repaired with surgery to replace the diseased portion of the aorta. The outlook is usually excellent.
Types of Aneurysm
Types of aneurysm include aortic aneurysms, cerebral aneurysms, and peripheral aneurysms.
Aortic Aneurysm
Most aneurysms occur in the aorta. The aorta is the main artery that carries blood from the heart to the rest of the body. The aorta comes out from the left ventricle of the heart and travels through the chest and abdomen. The two types of aortic aneurysm are thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA).
Thoracic Aortic Aneurysm
An aortic aneurysm that occurs in the part of the aorta running through the thorax (chest) is a thoracic aortic aneurysm. One in four aortic aneurysms is a TAA.
Most TAAs do not produce symptoms, even when they are large. Only half of all people with TAAs notice any symptoms. TAAs are identified more often now than in the past because of chest computed tomography (CT) scans performed for other medical problems.
In a common type of TAA, the walls of the aorta become weak and a section nearest to the heart enlarges. Then the valve between the heart and the aorta cannot close properly and blood leaks backward into the heart. Less commonly, a TAA can develop in the upper back away from the heart. A TAA in this location can result from and injury to the chest such as from an auto crash.
Abdominal Aortic Aneurysm
An aortic aneurysm that occurs in the part of the aorta running through the abdomen is an abdominal aortic aneurysm. Three in four aortic aneurysms are AAAs.
An AAA can grow very large without producing symptoms. About 1 in 5 AAAs rupture.
Cerebral Aneurysm
Aneurysms that occur in an artery in the brain are called cerebral aneurysms. They are sometimes called berry aneurysms because they are often the size of a small berry. Most cerebral aneurysms produce no symptoms until they become large, begin to leak blood, or rupture.
A ruptured cerebral aneurysm causes a stroke. Signs and symptoms can include a sudden, extremely severe headache, nausea, vomiting, stiff neck, sudden weakness in an area of the body, sudden difficulty speaking, and even loss of consciousness, coma, or death. The danger of a cerebral aneurysm depends on its size and location in the brain, whether it leaks or ruptures, and the person’s age and overall health.
Peripheral Aneurysm
Aneurysms that occur in arteries other than the aorta (and not in the brain) are called peripheral aneurysms. Common locations for peripheral aneurysms include the artery that runs down the back of the thigh behind the knee (popliteal artery), the main artery in the groin (femoral artery), and the main artery in the neck (carotid artery).
Peripheral aneurysms are not as likely to rupture as aortic aneurysms, but blood clots can form in peripheral aneurysms. If a blood clot breaks away from the aneurysm, it can block blood flow through the artery. If a peripheral aneurysm is large, it can press on a nearby nerve or vein and cause pain, numbness, or swelling.
Causes
An aneurysm can result from atherosclerosis (hardening and narrowing of the inside of arteries). As atherosclerosis develops, the artery walls become thick and damaged and lose their normal inner lining. This damaged area of artery can stretch or “balloon” from the pressure of blood flow inside the artery, resulting in an aneurysm.
An aneurysm also can develop from constant high blood pressure inside an artery.
A thoracic aortic aneurysm can result from an injury to the chest (for example, an injury that occurs from an auto crash). Certain medical conditions, such as Marfan syndrome, that weaken the body’s connective tissues, also can cause aneurysms.
In rare cases, infections such as untreated syphilis (a sexually transmitted infection) can cause aortic aneurysms. Aortic aneurysms also can occur as a result of diseases that cause inflammation of blood vessels, such as vasculitis.
Signs and Symptoms
The signs and symptoms of an aneurysm depend on its type, location, and whether it has ruptured or is interfering with other structures in the body. Aneurysms can develop and grow for years without causing any signs or symptoms. It is often not until an aneurysm ruptures or grows large enough to press on nearby parts of the body or block blood flow that it produces any signs or symptoms.
Abdominal Aortic Aneurysm
Most abdominal aortic aneurysms (AAAs) develop slowly over years and have no signs or symptoms until (or if) they rupture. Sometimes, a doctor can feel a pulsating mass while examining a patient's abdomen. When symptoms are present, they can include:
- Deep penetrating pain in your back or the side of your abdomen
- Steady gnawing pain in your abdomen that lasts for hours or days at a time
- Coldness, numbness, or tingling in your feet due to blocked blood flow in your legs
Thoracic Aortic Aneurysm
A thoracic (chest) aortic aneurysm may have no symptoms until the aneurysm begins to leak or grow. Signs or symptoms may include:
- Pain in your jaw, neck, upper back (or other part of your back), or chest
- Coughing, hoarseness, or trouble breathing
If a cerebral (brain) aneurysm presses on nerves in your brain, it can cause signs and symptoms. These can include:
- A droopy eyelid
- Double vision or other changes in vision
- Pain above or behind the eye
- A dilated pupil
- Numbness or weakness on one side of the face or body
Peripheral Aneurysm
Signs and symptoms of peripheral aneurysm may include:
- A pulsating lump that can be felt in your neck, arm, or leg
- Leg or arm pain, or cramping with exercise
- Painful sores on toes or fingers
- Gangrene (tissue death) from severely blocked blood flow in your limbs
Blood clots can form in peripheral aneurysms. If a clot breaks loose and travels through the bloodstream, it can lodge in your arm, leg, or brain and block the artery. An aneurysm in your neck can block the artery to the brain and cause a stroke.
How Is an Aneurysm Treated?
Goals of Treatment
Some aneurysms, mainly small ones that are not causing pain, can be treated with “watchful waiting.” Others need to be treated to prevent growth and complications. The goals of treatment are to prevent the aneurysm from growing, prevent or reverse damage to other body structures, prevent or treat a rupture, and to allow you to continue to participate in normal daily activities.
Treatment Options
Medicine and surgery are the two types of treatment for an aneurysm. Medicines may be prescribed before surgery or instead of surgery. Medicines are used to reduce pressure, relax blood vessels, and reduce the risk of rupture. Beta blockers and calcium channel blockers are the medicines most commonly used.
Surgery may be recommended if an aneurysm is large and likely to rupture.
Treatment by Type of Aneurysm
Aortic Aneurysm
Experts recommend that men who have ever smoked (at least 100 cigarettes in their lifetime) and are between the ages of 65 and 75 should have an ultrasound screening to check for abdominal aortic aneurysms.
Treatment recommendations for aortic aneurysms are based on the size of the aneurysm. Small aneurysms found early can be treated with “watchful waiting.”
- If the diameter of the aorta is small—less than 3 centimeters (cm)—and there are no symptoms, “watchful waiting” and a followup screening in 5 to 10 years may be all that is needed, as determined by the doctor.
- If the aorta is between 3 and 4 cm in diameter, the patient should return to the doctor every year for an ultrasound to see if the aneurysm has grown.
- If the aorta is between 4 and 4.5 cm, testing should be repeated every 6 months.
- If the aorta is larger than 5 cm (2 inches around or about the size of a lemon) or growing more than 1 cm per year, surgery should be considered as soon as possible.
The traditional and most common type of surgery for aortic aneurysms is open abdominal or open chest repair. It involves a major incision in the abdomen or chest. General anesthesia is needed with this procedure.
The aneurysm is removed and the section of aorta is replaced with an artificial graft made of material such as Dacron® or Teflon®. The surgery takes 3 to 6 hours, and the patient remains the hospital for 5 to 8 days. It often takes a month to recover from open abdominal or open chest surgery and return to full activity. Open abdominal and chest surgeries have been performed for 50 years. More than 90 percent of patients make a full recovery.
In endovascular repair, the aneurysm is not removed, but a graft is inserted into the aorta to strengthen it. This type of surgery is performed through catheters (tubes) inserted into the arteries; it does not require surgically opening the chest or abdomen.
To perform endovascular repair, the doctor first inserts a catheter into an artery in the groin (upper thigh) and threads it up to the area of the aneurysm. Then, watching on x ray, the surgeon threads the graft (also called a stent graft) into the aorta to the aneurysm. The graft is then expanded inside the aorta and fastened in place to form a stable channel for blood flow. The graft reinforces the weakened section of the aorta to prevent the aneurysm from rupturing.
Endovascular repair surgery reduces recovery time to a few days and greatly reduces time in the hospital. The procedure has been used since 1999. Not all aortic aneurysms can be repaired with this procedure. The exact location or size of the aneurysm may prevent the stent graft from being safely or reliably positioned inside the aneurysm.
Cerebral Aneurysm
Treatment for cerebral (brain) aneurysms depends on the size and location of the aneurysm, whether it is infected, and whether it has ruptured. A small cerebral aneurysm that hasn’t burst may not need treatment. A large cerebral aneurysm may press against brain tissue, causing a severe headache or impaired vision, and is likely to burst. If the aneurysm ruptures, there will be bleeding into the brain which will cause a stroke. If a cerebral aneurysm becomes infected, it requires immediate medical treatment. Treatment of many cerebral aneurysms, especially large or growing ones, involves surgery, which can be risky depending on the location of the aneurysm.
Peripheral Aneurysm
Most peripheral aneurysms have no symptoms, especially if they are small. They seldom rupture.
Treatment of peripheral aneurysms depends on the presence of symptoms, the location of the aneurysm, and whether the blood flow through the artery is blocked. Blood clots can form in a peripheral aneurysm, break loose, and block the artery.
An aneurysm in the back of the knee that is larger than 1 inch in diameter usually requires surgery. An aneurysm in the thigh also is usually repaired with surgery.
How Can an Aneurysm Be Prevented?
The best way to prevent an aneurysm is to avoid the risk factors that increase the changes of developing one. To do this, you can:
- Quit smoking.
- Eat a low-fat, low-cholesterol diet to reduce the buildup of plaque in the arteries. Plaque is a fatty buildup that narrows the arteries.
- Control high blood pressure (eating a low-salt diet helps).
- Control high cholesterol.
- Get regular physical activity.
Informations obtained from National Institute of Health.