What is an aneurysm and why is it important?
The word "aneurysm' means out-pouching or bulging of a portion of a blood vessel that can occur anywhere in the body. When an aneurysm occurs in the aorta, the largest blood vessel in the body, it is either a thoracic aneurysm, located near the heart, or an abdominal aneurysm, located in the descending portion of the aorta.
When a blood vessel wall bulges, or dilates, it becomes thin and tense, just like blowing too much air into a balloon. At a certain size, that dilated portion of the vessel wall is in danger of rupturing or tearing (called a "dissection"). This can be a life-threatening emergency.
The goal of surgery is to intervene before that happens by removing the dilated portion of the vessel and replacing it with a graft, or tube of synthetic material, that won't rupture or tear.
What causes an aortic aneurysm?
- Atherosclerosis (hardening of the arteries)
- Chronic or untreated high blood pressure
- Injury from trauma (for example, a car accident)
- Congenital abnormality (present from birth)
- Inherited conditions (for example, Marfan syndrome, Loeys-Dietz syndrome)
These are all conditions that have the potential to weaken the wall of the vessel, allowing it to dilate or balloon out over time.
What are the symptoms of an aortic aneurysm?
Aneurysms usually do not cause symptoms until they get quite large. They often are found during an examination for a different medical condition. When they are large enough to cause symptoms, people may notice chest or back pain, palpitations, fatigue, dizziness or shortness of breath.
Sudden severe back pain that feels like the worst pain anyone has ever had is usually a sign of a tear or rupture and is an extreme medical emergency.
How are aortic aneurysms discovered or diagnosed?
Large aneurysms can be seen on a chest x-ray. They are also detected by studies such as CT scan, MRI, or echocardiography. These studies also help to determine the exact location and size of the aneurysm. When a small aneurysm is found, the study used to find it is repeated on a regular basis, usually every six to 12 months, to monitor any change in size. This helps determine the ideal time for surgical intervention.
How is the aneurysm fixed?
Surgical repair involves opening the chest to expose the aorta in the area of the aneurysm. A heart-lung machine is connected to maintain circulation while the surgeon removes the diseased portion of the aorta. Clamps are placed above and below the aneurysm, which is then cut out and removed. A fabric tube, or graft, is sewn onto both cut ends to replace the diseased portion that is removed. The chest is then closed. The breastbone is closed with permanent wire closures to allow it to heal; the rest of the skin and muscle is closed with sutures that eventually dissolve. The skin may be closed with staples, which are removed one to two weeks after surgery, or with a special surgical glue that dissolves over time.
There is another technique for repairing an aortic aneurysm that can be used for patients who are at too high of a risk to undergo major surgery. This involves placing a device called a "stent graft" inside the diseased portion of the aorta without removing it. The stent is placed from the outside of the body through a catheter that is put through an artery leading to the aorta. This stent graft can relieve most of the pressure of blood flowing through the aneurysm, preventing rupture.
The Johns Hopkins Hospital is proud to be selected as one of only 13 hospitals nationwide that can perform endovascular abdominal aortic aneurysm surgery above the renal arteries. Find out more about this procedure and the fenestrated stent graft used.
How will I recover from aortic aneurysm surgery?
Recovery is similar to that of recovery from any open-chest procedure. This is described in the general section of this booklet discussing recovery from surgery.
In the future, it will be very important to:
- Permanently stop smoking
- Maintain very good blood pressure control
- Avoid heavy lifting
It is important to discuss all this with your cardiologist and primary care doctors.
What else should I know?
Some aortic aneurysms are located very close to the aortic valve (the valve that allows blood to leave the heart); this may cause the aortic valve to function improperly and let some blood leak backwards with each heartbeat. The additional strain on the heart can eventually result in heart damage. When this happens, the preferred surgical procedure may be to replace both the diseased portion of the vessel and the valve to which it is attached.
In addition, some medical centers such as Johns Hopkins specialize in a procedure that replaces the aneurysm that lies close to the aortic valve, but avoids replacing the valve, allowing the native valve to remain in place. The advantages of this procedure, referred to as a valve-sparing aortic root replacement, are the avoidance of either taking a lifelong blood thinner medication or having to undergo a second valve surgery 12 to 15 years in the future. Your surgeon will discuss this option in greater detail if appropriate.