It's Topic Tuesday!

Welcome back to Topic Tuesday! My name is Keyana Zahiri, and I am a medical student at the Warren Alpert Medical School of Brown University in Providence, RI, pursuing cardiac surgery. I am excited to be joining the Aortic Hope community and will be contributing to the medical information posts going forward!

Today we will be learning about a key topic in cardiac surgery: type A vs B aortic dissections. If you haven’t had a chance to read our previous posts about parts of the aorta and aneurysms of the aorta, make sure to check those out first! As a review, your aorta is the major blood vessel bringing fresh blood from your heart to the rest of your body and has a root, ascending, arch, and descending component. The aorta has three layers: the innermost tunica intima layer, the muscular middle tunica media layer, and lastly the outermost tunica adventitia layers. 

Before we dive into the difference between type A and B, let’s first discuss what an aortic dissection means. An aortic dissection happens when there is a tear in the inner intima layer of the aorta. This tear allows for blood to flow between layers of the aorta instead of straight through the pipeline towards the brain and rest of the body. Blood flowing at high pressure between the inner and middle walls of the aorta causes the layers to separate from one another, or dissect, which disrupts normal blood flow to the rest of the body.

https://www.mayoclinic.org/diseases-conditions/aortic-dissection/symptoms-causes/syc-20369496

An aortic dissection is a rare but life-threatening medical emergency. Symptoms of an aortic dissection include sudden, severe, tearing chest, back, or stomach pain, loss of consciousness, shortness of breath, leg pain, difficulty walking, weak pulses in one arm or leg compared to the other, and stroke-like symptoms such as vision problems, difficulty speaking, or weakness. If these symptoms are experienced, 911 should be called as soon as possible. 

There are two main types of aortic dissections: Stanford Type A and B. Type A dissections are more common and dangerous. These dissections involve a tear in the ascending or upper part of the aorta closer to the heart. These dissections can extend to the arch and full length of the aorta. Type A dissections usually require immediate surgery to repair or replace the damaged parts of the aorta. Type B dissections involve a tear only in the lower or descending parts of the aorta and can extend into the abdominal aorta. Surgery may be needed depending on the severity, however most cases are managed with medicine. 

https://www.saem.org/about-saem/academies-interest-groups-affiliates2/cdem/for-students/online-education/m4-curriculum/group-m4-cardiovascular/thoracic-aortic-dissection

Some risk factors for aortic dissections are having aortic aneurysms, high blood pressure, atherosclerosis (plaque buildup in arteries), usage of tobacco products, aortic valve disease, heart conditions present at birth such as a bicuspid (two instead of the normal three pieces) aortic valve, genetic and connective tissue disorders such as Turner, Marfan, or Ehlers-Danlos syndrome, traumatic injury to the chest, and more. 

Having an aortic dissection can be a very overwhelming and distressing experience, and surviving it can evoke many different emotions. The Aortic Hope family is here to make sure no one has to go through this experience alone. Whether you’re a patient, family member, friend, or just interested, Aortic Hope has support, resources, and a place for you in our community.  

Stay well,

Keyana Zahiri 

References:

Aortic dissection. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/aortic-dissection/symptoms-causes/syc-20369496. 

Thoracic Aortic Dissection. Default. https://www.saem.org/about-saem/academies-interest-groups-affiliates2/cdem/for-students/online-education/m4-curriculum/group-m4-cardiovascular/thoracic-aortic-dissection. 

What is aortic dissection? Cleveland Clinic. October 7, 2024. https://my.clevelandclinic.org/health/diseases/16743-aortic-dissection.