Aortic Aneurysm – Symptoms and Causes

ByJanis Updated

Overview

Aortic aneurysms occur when the wall of the aorta, the main artery carrying blood from the heart, bulges outward. These bulges can develop anywhere along the aorta and may be either tubular or round in shape.

There are two main types: abdominal aortic aneurysms, which form in the portion of the aorta passing through the belly, and thoracic aortic aneurysms, which develop in the chest cavity. Some individuals may develop both types simultaneously.

Having an aortic aneurysm increases the risk of aortic dissection, a serious condition where the inner layer of the aortic wall tears.

Understanding the Aorta’s Structure

The aorta can be divided into four main sections:

  1. Ascending aorta – begins at the heart with the aortic root (containing the aortic valve and coronary artery origins).
  2. Aortic arch – curves at the base of the neck, with three branches supplying blood to the brain and arms.
  3. Descending thoracic aorta – runs downward along the spine.
  4. Abdominal aorta – continues below the diaphragm and eventually divides into the iliac arteries at the pelvis.

The aorta itself consists of three layers:

  • A thin inner layer that prevents blood clotting
  • A muscular middle layer providing structural strength
  • A tough outer layer that holds everything together

What Are Aortic Aneurysms?

An aortic aneurysm develops when a section of the aorta enlarges and its wall becomes thinner. This thinning increases the risk of rupture, similar to an overinflated balloon that’s likely to pop.

As aneurysms grow larger, the risk of a life-threatening rupture increases significantly.

Aortic Dissection

Aortic dissection often occurs alongside aneurysms. This dangerous condition begins when the inner layer of the aorta tears.

Blood forces its way into the middle muscular layer, creating a new channel called the “false lumen” (as opposed to the normal “true lumen”).

As blood continues flowing into this false lumen, it can:

  • Reach and potentially tear into branch vessels
  • Compress branch vessels, cutting off blood flow to vital organs
  • Compromise the aortic valve, causing acute heart failure

When dissection involves the ascending aorta (called Type A dissection), emergency surgery is always necessary because the weakened aortic wall has a high risk of rupture.

Causes of Aortic Disease

Three main factors contribute to aortic disease:

  1. Structural Genetic Abnormalities: The aorta may be improperly formed from birth. Marfan syndrome is a classic genetic condition leading to aortic problems, but bicuspid aortic valve is actually the most common genetic abnormality associated with ascending aortic aneurysms.

  2. Accelerated Atherosclerotic Injury: This often stems from sustained high blood pressure, high cholesterol, smoking, obesity, and diabetes.

  3. Inflammatory Diseases: Less common causes include vasculitis and infections.

Detecting Aortic Problems

People with these risk factors should consider screening:

  • Family history of aortic disease
  • High blood pressure
  • Heart murmur

Screening typically starts with an echocardiogram (heart ultrasound), which can visualize the heart and ascending aorta. If this test suggests aortic disease, a CT scan is usually recommended for further evaluation.

When Surgery Becomes Necessary

The size of an aneurysm is the primary factor in determining when surgery is needed:

Patient Condition Size Threshold for Surgery
General population 5.5 cm or larger
Bicuspid aortic valve 5.0 cm or larger
Genetic disorders (e.g., Marfan syndrome) 4.5 cm or larger

Treatment options vary based on which section of the aorta is affected:

Ascending Aorta Repair

  • The damaged section is replaced with a Dacron graft
  • If the aortic valve is normal, it can be preserved (valve-sparing root replacement)
  • If the valve is abnormal, it can be replaced with a biological or mechanical valve

Aortic Arch Repair

  • Requires special techniques to protect brain function
  • Often performed along with ascending aorta repair

Descending Thoracic Aorta Repair

  • Surgery is typically recommended when the aneurysm reaches 5.5-6.0 cm
  • Can often be repaired using endovascular techniques
  • Endovascular repair involves inserting a Dacron graft through a peripheral artery and securing it with a metal stent
  • Requires only small incisions without opening the chest or abdomen

Thoracoabdominal Aortic Aneurysms

  • Most complex aneurysms affecting both chest and abdominal portions
  • Typically require open surgery with incisions in both chest and abdomen
  • Surgery is generally recommended when aneurysms reach 5.5-6.0 cm
  • Special techniques are used to minimize the risk of paraplegia
  • New technology is being developed to allow more endovascular repairs

Always discuss with your doctor about the benefits and risks of any recommended procedure.

Health Writer

Janis's areas of expertise include nutrition, exercise, stress management, and mental health. She is passionate about educating and empowering people to take control of their health and make positive changes that can last a lifetime. Janis believes that small, sustainable changes are the key to long-term success, and she works with her clients to develop personalized plans that fit their individual needs and lifestyles.