Thoracic Aortic Aneurysm

What is a thoracic aortic aneurysm?

The aorta is the main artery (blood vessel) that comes out of the heart and sends blood to the rest of the body. As it exits the heart, it gives off several branches to the head and arms and then makes a U-turn to go down through the chest. The part of the aorta in the chest that goes down toward the abdomen and the legs is called the "descending thoracic aorta." This is the most common part of the aorta in the chest to develop aneurysms.

An aneurysm is a blood vessel that has developed a thin wall and has bulged outward under the pressure of the bloodstream in the blood vessel. The main risk of all aneurysm is bursting (rupture). This is a life threatening event, but the risk of rupture depends on the size of the aneurysm. Small aneurysms may have virtually no risk of rupture, but large aneurysms may be at very high risk of rupture and need immediate repair. A vascular specialist is required to determine the risk of rupture and the need for surgery.

What are the available treatments for thoracic aortic aneurysm?

The treatment for thoracic aortic aneurysm depends on its size. For thoracic aortic aneurysms less than 6 cm in diameter (width), no treatment is recommended unless the aneurysm causes symptoms such as pain. The patient will need at CT scan of the chest every 6 months to see if the aneurysm has grown larger. Unfortunately, no medicine can cause the aneurysm to stop growing or to shrink.

If the aneurysm is larger than 6 cm in diameter, surgery is generally recommended. There are two kinds of surgery to fix an aneurysm of the descending thoracic aorta: traditional open surgery and minimally invasive stenting.

Open surgery involves a large incision on the left side of the chest and replacement of the aneurysm with an artificial, fabric graft. This surgery is usually performed in conjunction with a cardiothoracic surgeon. It requires a hospital stay of at least 5-7 days with at least a few days in the intensive care unit. Complete recovery may take several months.

Minimally invasive stenting of the descending thoracic aortic aneurysm can be performed through a small incision in one of the groins with a small puncture in the other groin. A special kind of stent is placed inside the aneurysm and creates a new channel for blood flow. The thin, weakened part of the aorta (the aneurysm) is now separated from the high pressure of the blood stream, and this protects against rupture. Recovery from this surgery is usually very quick, with many patients leaving the hospital the next day. Follow-up CT scans are required every 6 months to make sure the stent is working. Not every patient is a candidate for a stent, and a vascular surgeon experienced with thoracic aortic stents is required to evaluate each patient to determine whether a stent would work.

Both techniques effectively treat the aneurysm. The main risk of either surgery is paralysis from interrupting the blood flow to the spinal cord. Stroke and heart attack are also risks.