What Happens During an Aortic Dissection?

An aortic dissection is an uncommon emergency medical condition that occurs when there is a tear, or rupture, in the inner layer of the aorta. The aorta is the biggest artery in the human body, and it carries fresh, oxygenated blood from the heart to the rest of the body.

When a tear or rupture occurs in the inner lining of the aorta, blood can flow into the space between the inner and outer layers of the artery, creating a false channel or "dissection."

This article covers what you need to know about aortic dissection, including types, symptoms, when to call 911, causes, diagnosis, and treatment.

What Happens With Aortic Dissection

The aorta is the main artery that takes oxygenated blood from the heart to supply the rest of the body. The aorta's three layers are:

• The inner layer (intima)
• The middle layer (media)
• The outer layer (adventitia)

An aortic dissection begins with a tear in the inner layer of the aorta. This tear allows blood to enter the wall of the aorta, creating a false channel between the inner and outer layers of the artery.

Aortic Dissection

As blood enters the false channel, the inner and outer layers of the aortic wall can become separated, leading to the characteristic "dissection" of the aorta.

The presence of this false channel can disrupt normal blood flow in the aorta. Depending on the location and extent of the dissection, blood flow to various organs and tissues can be compromised. This may lead to several complications, such as:

• Reduced blood supply to vital organs, such as the heart, brain, and kidneys, can lead to organ failure or dysfunction.
• In some cases, the weakened aortic wall may rupture, causing massive internal bleeding. This is a catastrophic event and is often fatal.
• Aortic dissections can affect the heart's function, leading to conditions like a heart attack or abnormal heart rhythms.
• If the dissection extends into the blood vessels that supply the brain, it can cause a stroke.

Immediate medical treatment is essential. Aortic dissections are often managed surgically and with medication, and the specific approach used depends on the individual case.

Types of Aortic Dissection

There are two main types of aortic dissection, and each depends on location:

Type A

A type A aortic dissection means the tear or problem starts in the part of the aorta that's close to the heart, or the upper portion of the aorta.

This type is usually more serious and urgent because it can affect important blood vessels that go to the brain and other vital organs. Healthcare providers often treat Type A dissections with open-heart surgery to fix the damaged part of the aorta.

Type B

Type B is the type occurring farther away from the heart. It means the tear happens in the lower part of the aorta, toward or within the abdomen. Type B dissections are still serious, but they tend to be a bit less urgent than type A.

Healthcare providers might treat type B dissections with medications to lower blood pressure or sometimes with a procedure in which they put a special tube (stent) into the blood vessel to help seal off the tear and prevent it from worsening.

Aortic Dissection Symptoms

Aortic dissection symptoms typically appear suddenly, and the pain can feel severe, similar to a heart attack. The pain experienced during an aortic dissection is often described as sharp, stabbing, or even tearing.

Initially, this discomfort may be localized beneath the breastbone but may move beneath the shoulder blades or even toward the back. As the condition progresses, the pain may move around, traveling to areas like the jaw, neck, shoulders, arms, abdomen, or even the hips.

The symptoms of aortic dissection are primarily caused by the disruption of normal blood flow to the body's organs and tissues. These symptoms can include:

• Feelings of anxiety and impending doom or a sense that something is terribly wrong
• A rapid and weak pulse
• Episodes of fainting or dizziness
  
• Nausea and vomiting as the body reacts to the distress.
• Noticeable paleness of the skin
• Profuse sweating
  
• Shortness of breath, especially when lying flat

Additional symptoms that may accompany an aortic dissection include:

• Abdominal pain, which can arise if the dissection extends into the abdominal aorta
• Stroke symptoms, which can develop when the dissection affects blood vessels leading to the brain
• Difficulties with swallowing due to pressure on the esophagus

When to Call 911

If you or someone else is experiencing aortic dissection symptoms, you should immediately call 911. Symptoms like severe chest or back pain, especially if it feels like tearing or ripping, should not be taken lightly. Aortic dissections are life-threatening emergencies, and prompt medical attention is crucial for diagnosis and treatment. 

Aortic Dissection Causes and Risk Factors

The exact cause of an aortic dissection can vary, but some common risk factors and causes include:

• High blood pressure: Puts stress on the aortic walls, making them more prone to tears or dissections
  
• Atherosclerosis: A buildup of fatty deposits in the arteries that can damage the aortic wall
  
• Aging
  
• Severe trauma, such as car accidents or falls
  
• Pregnancy
  
• Having had aortic surgeries or interventions in the past
• Connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome
  
• Being assigned male at birth vs. female
  

It's important to note that aortic dissection is a complex condition often influenced by multiple factors. Having one or more of these risk factors does not guarantee that a dissection will occur, but it does increase the likelihood.

How Aortic Dissection Is Diagnosed

Healthcare providers use several methods to diagnose an aortic dissection.

First, they perform a thorough physical exam, checking things like blood pressure, listening to the heart, and evaluating pulses. Noticing signs like a heart murmur or abnormal pulses can raise their suspicion of aortic dissection.

It's important to know that certain common tests, like an electrocardiogram (ECG or EKG) or chest X-ray, may not always detect an aortic dissection.

To get a more accurate diagnosis, healthcare providers often turn to advanced imaging tests, including:

• Computed tomography (CT) scan: A test that uses multiple X-ray images to create pictures within the body
• Transesophageal echocardiograms (TEE): An imaging test that involves inserting a probe down the throat to collect heart images
• Magnetic resonance imaging (MRI): An imaging test that uses magnets and radio waves to collect images
• Transthoracic echocardiogram (TTE): An ultrasound performed on the chest wall that collects heart images

These tests are very good at spotting aortic dissections, but which one is used can depend on what the hospital has available and the patient's specific needs. CT scans, for instance, use contrast dye to see inside the aorta and its branches.

Transesophageal echocardiograms involve an ultrasound probe placed down the esophagus to image the heart and aorta. MRI scans, while highly accurate, take longer and may not be the first choice.

How Aortic Dissection Is Treated

The treatment for an aortic dissection often involves a combination of surgical and medical interventions. The specific treatment approach depends on various factors, including the location and extent of the dissection and the overall health of the patient.

Medications

Controlling blood pressure is a crucial part of managing aortic dissection. Medications, such as beta-blockers and vasodilators, are often administered to reduce the force of blood pumping against the weakened aortic wall. This helps decrease the risk of the dissection progressing or rupturing.

Surgery

Surgery to repair the damaged aorta and prevent further complications. The two main surgical approaches are:

• Open surgery: In this procedure, a surgeon makes an incision in the chest or abdomen, stops the blood flow in the aorta, and replaces the damaged portion of the aorta with a synthetic graft.
  
• Endovascular aortic repair: This involves inserting a stent graft (a fabric-covered metal tube) through small incisions in the groin or other arteries and guiding it into the aorta to seal off the false channel and reinforce the weakened aortic wall.
  

Aortic Dissection Complications

Aortic dissection disrupts blood flow and can lead to various complications, including:

• Stroke
• Heart attack, irregular rhythms, or heart failure
• Abdominal pain or bowel issues
• Kidney injury or failure
• Severe leg pain, numbness, and potential tissue damage

Prompt treatment is crucial to minimize damage to these organs and improve recovery chances.

Outlook for Aortic Dissections

The outlook for aortic dissections depends on several factors, including the location and extent of the dissection, how quickly it is diagnosed and treated, and the patient's overall health.

However, aortic dissections continue to pose significant mortality risk (risk of dying). A substantial portion, around 30%, do not survive past their arrival at the emergency room, and even with surgical intervention, mortality rates range between 20% to 30%.

Even with successful treatment, individuals may require long-term follow-up care and lifestyle changes to manage related health risks, such as high blood pressure and aortic aneurysms.

How to Prevent Aortic Dissection

Aortic dissection is not always preventable. However, there are proactive measures you can take to minimize your risk, such as:

• Manage and address atherosclerosis, which is a hardening of the arteries
• Manage high blood pressure per your healthcare provider's instructions
• Exercising caution to prevent injuries that may lead to aortic dissections
• Visiting your healthcare provider regularly to monitor your condition if you've been diagnosed with Marfan or Ehlers-Danlos syndromes
  

Summary

In summary, aortic dissection is a serious medical condition characterized by a tear in the aortic artery wall. This condition can lead to severe complications, including organ damage and death.

While aortic dissections cannot always be prevented, managing risk factors like atherosclerosis and high blood pressure, taking safety precautions, and seeking regular follow-up care for underlying conditions can help minimize the chances of this life-threatening condition.

Immediate medical attention is essential if symptoms arise, such as sudden, intense chest or back pain. If you or a loved one has signs of an aortic dissection, call 911 or go to your local emergency room as soon as possible.