Aortic Aneurysm

The aorta, the largest artery in the body, transports oxygen rich blood from the left ventricle of the heart to the rest of the body. As it emerges from the left ventricle of the heart, the aorta has the shape of a walking cane, with an ascending part, an arch, and a descending part that travels through the chest and continues into the abdomen. From the aorta, branches to the head, arms, chest, abdomen, and legs supply the body with oxygen and nutrients.

An aortic aneurysm is a dilation, bulging, or ballooning of a weakened part of the aortic artery wall. The normal pressure of blood from the pumping of the heart causes the weakened portion of the aorta to slowly stretch and bulge, leading to the formation of an aneurysm. Aortic aneurysms are named according to their location:

  • thoracic aortic aneurysms are those that form in the chest cavity
  • thoracoabdominal aneurysms extend from the chest into the abdomen
  • abdominal aortic aneurysms occur exclusively in the abdominal portion of the aorta

Regardless of their location, aortic aneurysms are dangerous because of the risk that they will rupture, causing life-threatening hemorrhage.

Learn more about aortic aneurysm surgery at the Aortic Surgery Program.

What are the risk factors for aortic aneurysm?

Disorders such as emphysema, chronic hypertension or atherosclerosis, inherited diseases, such as Marfan's syndrome or Ehlers-Danlos syndrome, and smoking can increase the risk of aortic aneurysm formation. The children or siblings of people with aortic aneurysms are also at increased risk for aneurysm formation.

What are the symptoms of aortic aneurysm?

Often, individuals with aortic aneurysms do not have specific symptoms; rather, the main complaint can be vague pain in the chest or abdomen. Thoracic aneurysms can affect nearby structures, like the trachea, causing a persistent cough. Compression of nerves by a thoracic aneurysm can cause hoarseness. In severe cases, abdominal aneurysms can cause gastrointestinal bleeding. In some cases, people might feel a pulsing in the abdominal or thoracic area where the aneurysm is located. The symptoms of a ruptured aneurysm include a sudden intense back or abdominal pain (or chest pain, in the case of a thoracic aortic aneurysm), or signs of shock such as shaking, dizziness, fainting, sweating, rapid heartbeat, and sudden weakness.

How is an aortic aneurysm diagnosed?

Since aortic aneurysm often does not produce symptoms, it is important for people at increased risk for aortic aneurysm formation (for example, those with a family history) to undergo screening for the condition with noninvasive testing. Aneurysms can also be discovered during a routine medical examination, during an abdominal surgery, or during a diagnostic imaging test. The common diagnostic tests for aortic aneurysm are:

  • ultrasound
  • angiography
  • computerized tomography (CT) scan
  • magnetic resonance imagery (MRI)

What are the treatment options for an aortic aneurysm?

Treatment for an aneurysm varies according to its severity and size. If a rupture is not imminent, the physician may decide to monitor the growth of the aneurysm using ultrasound and CT scans, and attempt to lower the pressure on the aneurysm using medication to lower the blood pressure. Thoracic or thoracoabdominal aneurysms whose diameter is twice the size of the normal aorta — or about 5.5 cm — should be considered for surgical repair. In some cases, a minimally invasive procedure called endovascular stent graft aortic aneurysm repair may be performed.

Abdominal Aortic Aneurysm Repair

Open surgery for aortic aneurysm repair is a very well investigated procedure that is considered to carry a low risk of complications and to have a very good success rate. Its aim is to replace or fortify the damaged portion of the vessel (aorta).

General anesthesia is required for the procedure. An incision is made in the abdomen, and blood flow to the aortic artery is reduced (often by clamping the aorta) in order to facilitate the surgical procedure. The aneurysm is removed, and the affected vessel walls are reinforced with a woven graft (tube) made of synthetic (man made) material, such as Dacron. This graft will bypass the weakened walls of an aneurysm, allowing normal bloodflow to the legs and other organs. Once the graft is in place, blood flow is allowed to resume through the artificial or reinforced artery, and the incision on the abdomen is closed with sutures or surgical staples. The procedure takes approximately 4 hours. In-hospital recovery from the surgery takes approximately seven days.

In many cases, endovascular stent graft aortic aneurysm repair, a minimally invasive procedure, is possible as an alternative to open surgery.

Minimally Invasive Procedures

Endovascular Stent Graft Aortic Aneurysm Repair

Endovascular surgery is a relatively new technique that uses minimally invasive procedures to correct problems in blood vessels from within the vessels themselves. For aortic aneurysm repair, endovascular stent graft insertion is often used in patients whose overall health may make open surgery too dangerous. Studies of the procedure suggest that it carries a low risk of complications and has a very good success rate. It also has a significantly shorter recovery time than conventional treatment using open surgery aortic aneurysm repair.

Endovascular stent graft insertion may require only local or regional anaesthesia. With the use of a catheter inserted via an artery through a short incision in the groin, a stent graft made of a synthetic (man made) material is inserted into the aortic artery. Using x-ray imaging, the surgeon guides the stent graft through the catheter to the damaged area of the aorta. Using a small balloon, also inserted through the catheter, the stent graft is then expanded to sit snugly inside the artery. The stent graft provides a reinforced channel for the blood to flow and thereby reduces the pressure on the damaged area (aneurysm) of the artery. This, in turn, prevents the aneurysm from rupturing. At the end of the procedure, the catheter is removed. Patients generally go home the following day.

Animation of Fenestrated Endovascular Graft to Repair an Abdominal Aortic Aneurysm