An aneurysm is an abnormal defect that looks like a permanent bulging or ballooning in the wall of an artery. (See diagram) Aneurysms can form in any blood vessel in the body. They occur when the arterial wall becomes weak or damaged by accumulation of cholesterol-containing fatty deposits from atherosclerosis. Once elasticity is reduced, the force of the heartbeat can cause the artery to slowly stretch and bulge. The pressure of blood passing through can force part of a weakened artery to bulge outward, forming a thin-skinned blister.
 Although any weak blood vessel can be affected, aneurysms usually form in the abdominal or thoracic portion of the aorta or iliac arteries. The aorta is the main blood vessel that carries blood from the heart, in the arteries nourishing the heart, or in the arteries nourishing the brain. Aneurysms in any of these places are serious, while those in peripheral arteries are often less hazardous.
The gravest threat an aneurysm poses is that it will burst and cause damage. In the head, this can cause a stroke, or when located in the abdomen rupture can cause a life-threatening hemorrhage. Even if it does not rupture, a large aneurysm can impede circulation and promote unwanted blood clot formation and embolism. Aneurysms do not always enlarge and not all aneurysms will require treatment, only monitoring. Aneurysms are often first detected as a mass on a standard x-ray. Detecting an aneurysm on your own is difficult since symptoms are rare. A CT scan or a MRI is usually used to determine the exact size and location of the aneurysm.
The King vascular practice handles all cases of aneurysm except of those located in the brain, which are referred to neurosurgeons. The information below concentrates on the most common form of aneurysm, the abdominal aortic aneurysm.
Contributing Causes for Aneurysms
The exact cause of abdominal aortic aneurysm is unknown, but in many instances, aneurysms are associated with other types of cardiovascular disease. The main risks are hypertension and atherosclerosis. Abdominal aneurysms are more common in men than women and are most prevalent in Caucasians. Some of the contributing causes to the weakening of the arterial wall are as follows:
Symptoms for Aneurysms
Abdominal aortic aneurysms can affect anyone, but are most often seen in men ages 40-70 years old. Aneurysms may develop slowly over many years and often have no symptoms. If the aneurysm expands very rapidly, tears in the bulging portion-or rupture- with blood leaking from the wall of the vessel may cause symptoms to develop very suddenly. Symptoms may result from pressure caused by the aneurysm pressing against organs, nerves, and other blood vessels.
Although most aneurysms produce no symptoms in some cases, the following may occur:
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Sudden & severe pain or unusual pulsing sensation where the aneurysm is located
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Pain in the abdomen or lower back extending into the groin with an abdominal aneurysm
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Pain in the chest, hoarseness, persistent coughing and difficulty swallowing with a thoracic aneurysm
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Throbbing sensation or lump directly behind the knee with a popliteal aneurysm
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Severe headache, unlike any experienced previously, with an aneurysm in the head
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Shortness of breath
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Nausea, decreased appetite, or decreased urine output with abdominal aortic aneurysm
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With rupture, signs of shock such as pallor, rapid pulse, clammy skin, fainting
Diagnosis of Aneurysms
Careful physical examination can often detect a large percentage of abdominal aortic aneurysms. By placing a stethoscope on the patient's abdomen, the doctor can often pick up signs of turbulent blood flow over the roughened surface of the aorta. Gentle pressure on the abdomen can help determine whether there is a pulsating mass. When the patient is overweight, it makes the examination less accurate. A thorough medical history with risk profile is taken to assess overall health and condition. Further evaluation with ultrasound is often needed to determine the diagnosis.
Diagnostic Testing
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Physical examination
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Auscultation, or listening, to the abdomen with a stethoscope
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X-ray of the area
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Ultrasound of the area to view organs
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MRI (magnetic resonance imaging) to visualize soft tissues such as veins and arteries
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CT scan (computed topography) to obtain cross-sectional images of body tissues
Risk of Rupture with Abdominal Aortic Aneurysm
The risk of rupture can not be absolutely determined, but based on research, the following information can assist in predicting the risk profile:
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The location of the aneurysm
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The current size of the aneurysm
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The rate of recent size increases
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The onset of symptoms such as back pain
Treatment for Abdominal Aortic Aneurysm
Many factors are considered in the evaluation and recommendation for treatment, including overall general health, cardiac status, and risk of rupture. There are no absolute numbers, but those abdominal aortic aneurysms 6-cm and over in maximal diameter are nearly always considered surgical candidates. With generally healthy patients, the recomendation for surgical intervention is often at 5-cm or more.
Surgery is the only cure for abdominal aortic aneurysm. However, the timing of surgical treatment is based on the relative risk of surgery versus the relative risk of rupture. The goal of treatment is timely surgical intervention before complications develop. The risk of complications increase as the size of the aneurysm increases. If the aneurysm is small and there are no symptoms, regular periodic evaluation to watch for changes may be recommended. Because surgery for abdominal aortic aneurysm is somewhat risky, it may be recommended to wait for the aneurysm to expand to a certain size before operating, when the risk of complications exceeds the risk of surgery.
Symptomatic aneurysms often require treatment to prevent complications. Anti-hypertensive medications may be prescribed to reduce blood pressure as part of the treatment plan. Rupture occurs when the weakened wall of the blood vessel finally tears, much as a stretched out elastic band will finally snap under pressure. The expectation or prognosis is good when the aneurysm is monitored carefully and if surgical repair is performed before the aorta ruptures. Aortic rupture is life threatening and less than 50% of all people with ruptured abdominal aortic aneurysms survive.
Surgery is usually needed when the diameter of the aneurysm enlarges to at least 2 inches, or around 5-6 cm. This operation is performed under general anesthesia, involves an incision into the abdomen to open the aorta, remove the cholesterol and fatty build-up, and to cut away the weakened portion of the blood vessel. The surgeon will replace the enlarged portion of the blood vessel with a flexible synthetic or manmade graft. The whole procedure usually takes 3-4 hours time.
 
Left:Aneurysm before surgery.
Right:Aneurysm repaired with graft
Recovery from an elective, or planned surgical repair takes approximately 6 weeks to regain strength and to return to normal activities. The post-operative stay typically involves several days spent being monitored in the hospital. A post-operative follow-up visit is scheduled for six weeks, and then at one-year annual intervals, with lifelong follow-up care recommended. After surgery, the patient can reduce the risk of further problems by taking the prescribed medications, eating a low fat diet, staying active with a walking or similar program, and never smoking any tobacco.
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