What is an aortic dissection?
An aortic dissection is a tear in the inner lining of the aorta. When this inner lining tears, blood escapes from the lumen of the aorta, where blood usually flows, into the lining. Once blood enters the lining, it separates the layers of the aortic wall. At high pressures, this can lead to a rupture of the aorta, which can be fatal.
An aortic dissection is classified as Type A if it occurs in the ascending portion of the aorta, or Type B if it occurs in the descending portion of the aorta. Type A dissections are an emergency and typically require surgical intervention, while Type B dissections may be managed without surgery by carefully controlling blood pressure.
How common is an aortic dissection?
Aortic dissection is relatively uncommon, with an incidence of approximately 3 per 100,000, and occurs more frequently in men over the age of 60. Death resulting from dissection is even more uncommon, with an incidence of approximately 1 in 100,000.
Aortic Dissection Causes
What are the causes of aortic dissection?
There are numerous factors that will increase the risk of aortic dissection. Many are related to aortic aneurysms and other aortic diseases. Some risk factors include:
- A history of aortic aneurysm
- Hypertension, or high blood pressure, especially a sudden increase in blood pressure
- Atherosclerosis, or hardening of the aortic walls
- Hypercholesterolemia, or high cholesterol
- Injury to the chest or stomach
- A family history of aortic dissections
Certain valve diseases, like bicuspid aortic valve disease and a narrowing of the aorta called aortic coarctation, are associated with an increased risk. Genetic disorders affecting collagen, including Marfan and Ehlers-Danlos syndromes, are also correlated with an elevated risk of aortic dissection, as is Turner’s syndrome.
Aortic Dissection Symptoms
What are the symptoms of aortic dissection?
Aortic dissection symptoms appear suddenly and are severe, having many similarities with a heart attack. For this reason, aortic dissection is frequently misidentified as a heart attack in the emergency room, though specialized imaging techniques now lower the chance of misdiagnosis.
Symptoms of an aortic dissection include:
- Sudden, acute pain in the chest or back
- A change in pulse
- Shortness of breath
- Losing consciousness
Experiencing any of these symptoms warrants a visit to the emergency room.
Aortic Dissection Diagnosis
How is an aortic dissection diagnosed?
If an aortic dissection is suspected, CT angiography or MRI may be used, followed by a confirmation of the diagnosis using transesophageal echocardiography (TEE), where ultrasound images of the heart are taken from the esophagus.
Following a diagnosis, a treatment will be recommended based on whether the dissection is Type A or Type B.
Aortic Dissection Treatment
What is the treatment for aortic dissection?
A Type A aortic dissection is a medical emergency and requires surgery to repair the tear before further damage occurs. The most typical surgery for aortic dissection is valve sparing root replacement, or the David procedure. As the name suggests, this procedure preserves the aortic valve, attaching it to a graft that replaces the ascending aorta.
A Type B aortic dissection, on the other hand, does not necessarily need surgical intervention. Instead, blood pressure is managed with medication in order to avoid further damage, though complications from aortic dissection can develop. In order to minimize the chance of these complications, elective endovascular repair is a less invasive surgical option where a graft redirects blood flow away from the dissection.