Aortic Dissection
Aortic dissection is a serious, often life-threatening condition in which the inner layer of the aorta—the body’s largest blood vessel—develops a tear, allowing blood to enter the wall of the artery and split (dissect) its layers. This creates a false channel for blood flow that can compromise blood flow to vital organs, weaken the vessel wall, and potentially lead to rupture. Aortic dissection most often involves the chest portion of the aorta and is a medical emergency that requires rapid diagnosis and treatment. CT angiography is the primary imaging tool used for evaluation.
What is it?
The aorta is the body’s largest artery. It rises from the heart, arches over and gives off branches to the head, neck, and arms, and then travels downward through the chest and abdomen, providing blood to nearly every organ. The wall of the aorta has three layers: an inner lining (intima), a thick middle muscular layer (media), and an outer layer (adventitia). In an aortic dissection, a tear in the inner lining allows blood under high pressure to enter the middle layer, creating a false channel that splits the wall along the length of the artery.
Dissections are most commonly classified by where they occur. The Stanford system divides dissections into two types: type A, which involves the ascending aorta (the part rising directly from the heart), and type B, which involves only the descending aorta (beyond the branches to the head and arms). This distinction is important because type A dissections are typically a surgical emergency, while type B dissections are often initially managed with medical therapy, though some require endovascular or surgical treatment. The DeBakey classification is also used and further subdivides dissections based on the extent of involvement.
Most aortic dissections are related to chronic high blood pressure, which over many years weakens and stresses the aortic wall. Other important risk factors include connective tissue disorders such as Marfan syndrome, Loeys-Dietz syndrome, Ehlers-Danlos syndrome, and bicuspid aortic valve; pre-existing aortic aneurysm; family history of aortic disease; pregnancy (particularly in patients with underlying connective tissue disorders); cocaine or amphetamine use; trauma; certain inflammatory and vasculitis conditions; and prior aortic surgery or catheter-based procedures. Older age and male sex also increase risk.
Symptoms typically begin suddenly and are often severe. The classic symptom is intense chest or back pain that is sudden in onset and is sometimes described as “tearing,” “ripping,” or “stabbing.” Pain may move as the dissection extends, traveling from the chest to the back, between the shoulder blades, or into the abdomen. Other symptoms depend on which branches of the aorta are involved and may include shortness of breath, fainting, weakness or numbness on one side of the body (stroke-like symptoms), abdominal pain, leg pain, loss of pulses in a limb, asymmetric blood pressures, signs of heart failure, hoarseness, or symptoms of shock. Less commonly, dissections may present in atypical ways, and a high index of suspicion is needed, especially in patients with risk factors.
CT angiography of the chest, abdomen, and pelvis is the primary imaging test for evaluating suspected aortic dissection because it provides detailed visualization of the aorta and its branches and can identify the location, extent, and complications of the dissection. MR angiography may be used in stable patients, particularly when avoiding radiation or iodinated contrast is preferred. Transesophageal echocardiography (TEE) is especially useful for unstable patients in the emergency department or operating room. Chest X-ray, ECG, and blood work (including markers of organ damage and certain biomarkers) provide supportive information but are not sufficient on their own to confirm or exclude the diagnosis.
Important to Know
Aortic dissection is a true emergency. Time-sensitive treatment focuses on controlling blood pressure and heart rate, relieving pain, and quickly determining the type and extent of the dissection. Aggressive blood pressure and heart rate management—usually with intravenous medications—helps reduce the forces that drive the dissection forward and lowers the risk of complications such as rupture or extension.
For dissections involving the ascending aorta (Stanford type A), emergency open surgery is generally required because of the high risk of life-threatening complications such as aortic rupture, blood collection around the heart (cardiac tamponade), or stroke. For dissections involving only the descending aorta (Stanford type B), most uncomplicated cases are initially managed with intensive medical therapy. Endovascular stent grafting (TEVAR) or surgery is reserved for type B dissections with complications—such as poor blood flow to organs, persistent pain, expansion of the false channel, or aneurysm formation.
Long-term follow-up after aortic dissection is essential. Patients require lifelong blood pressure control, regular imaging surveillance of the aorta, and, in many cases, ongoing care with cardiothoracic surgery, vascular medicine, cardiology, and primary care. Patients with connective tissue disorders or strong family histories of aortic disease may also benefit from genetic counseling and screening of relatives.
Because aortic dissection can mimic other conditions—such as heart attack, pulmonary embolism, and severe musculoskeletal pain—prompt diagnosis depends on careful clinical evaluation and appropriate imaging. Patients with sudden, severe chest or back pain, especially those with known risk factors, should seek emergency medical care without delay.
Red flag symptoms include sudden severe chest or back pain (especially with tearing or ripping quality), pain radiating between the shoulder blades, shortness of breath, fainting, weakness or numbness on one side of the body, sudden severe abdominal pain, asymmetric pulses or blood pressures, or signs of shock. These warrant immediate emergency evaluation.