The aorta is the largest artery (blood vessel) in the body and carries oxygen-rich blood away from the heart to all parts of the body. Aortic occlusion is a blockage of the aorta somewhere along its path. Aortic occlusion can result in long-term damage to the organs.
Atherosclerosis, commonly referred to as hardening of the arteries, is a condition in which plaque, made up primarily of cholesterol and fatty acids builds up in the arteries. As atherosclerosis progresses, a portion of the aorta can be completely blocked by plaque or by a blood clot lodged in a narrowed section. When this happens, the tissues below the blockage will not receive enough blood or oxygen. There are multiple factors that increase the risk of developing atherosclerosis that can cause aortic occlusion. The more risk factors, the greater the severity of the disease.
The most common risk factors include:
- High cholesterol or a high fat diet, or both
- High blood pressure
- Age over 60
- Family history
Individuals suffering from aortic occlusion may experience:
- Cramping or aching in the hip, buttocks, thighs, or calves after activity that goes away when activity is stopped, but that returns when activity resumes.
- Pain in the hip, buttocks, thighs, or calves that increases when climbing stairs or going uphill.
- Pain in a limb when resting. This is a symptom of severe arterial blockage.
When aortic occlusion is suspected, a physician will perform a physical exam on the patient, ask questions about symptoms and determine any risk factors for arterial disease, order a study of the patient's blood flow in the vascular laboratory. During the blood flow study, a vascular lab technician will check the blood flow in a patient's abdomen, legs, and feet using the following tests to determine if there is adequate blood flow to the legs. Inadequate blood flow is called peripheral artery disease (PAD).
- Ankle-brachial index (ABI) - a series of blood pressure readings that compares the blood pressure in the ankle and foot with the blood pressure in the arm.
- Doppler ultrasound - an ultrasound that looks at the blood flowing through the arteries. It can show changes in blood flow due to narrowing or blockage of an artery.
- CT Angiography – a CAT scan with IV contrast dye to determine the extent of blockage and to plan surgical repair.
- Catheter angiography – injection of contrast dye into the aorta through a tube inserted into the aorta from the leg artery or an artery in the arm.
Patients diagnosed with aortic occlusion can take steps to reduce the arterial damage caused by atherosclerosis by quitting smoking immediately. A minimally invasive endovascular treatment to improve circulation in the legs may be recommended for patients who have severe abdominal aortic occlusion, particularly if the condition does not improve with the measures described. If a blockage is more extensive or cannot be treated with an endovascular procedure, bypass surgery may be required. Endovascular procedures available to repair a narrowed artery or short blockage include:
- Angioplasty which uses a tiny balloon to open blocked arteries. The balloon is inflated and deflated several times to crush the plaque against the artery wall. Once the artery has been unblocked, the balloon is deflated and removed. Blood can flow freely through the widened artery.
- Stenting which involves the insertion of a tiny wire mesh tube into an artery to hold it open. The collapsed stent is mounted onto a balloon catheter and guided across the blockage. The balloon is inflated to open the stent, which locks into place inside the artery. The balloon is deflated and removed, leaving the stent in place, holding the artery open.
The procedures can be completed through a small puncture, usually at the groin and general anesthesia isn’t needed which results in a much quicker recovery and fewer complications than with traditional open bypass surgery.
In many cases of aortic occlusion, reconstruction of the aorta will repair creating a new aorta using a fabric tube sewn to the aorta above the blockage and to the arteries in the groin to restore blood flow to the legs (aortobifemoral bypass).