It's Topic Tuesday!

Welcome back to another Topic Tuesday, everyone! Today, we'll be going over my favorite segment of the aorta- the root!

What Is the Aortic Root?

As you may know, the aorta is the largest artery in the body. The very first part of the aorta, right where it branches off of the heart, is known as the aortic root. This section may be short—normally only ~3 cm in length—but it is an intricate structure with several important functions.

https://ebook.sts.org/sts/view/Cardiac-and-Congenital/1864054/all/Aortic_Valve_Replacement__Mechanical__Bioprosthetic__Stentless_

The Three Key Components of the Aortic Root

1. Aortic Valve: The aortic valve separates the left ventricle (heart) from the aortic root. The valve and root are intimately related, as the annulus of the valve (where the valve leaflets attach to the walls) provides stability to the base of the root. If the annulus weakens, the root can stretch and form a thin aneurysm with the risk of dissection or rupture. Malfunctioning valves can also create turbulent flow that may contribute to aneurysm formation.

2. Sinuses of Valsalva: These are three small outpouchings or "pockets" located just above the aortic valve, one for each of the valve leaflets. They house the origins of the coronary arteries, which supply the heart muscle with blood. Specifically, the left coronary artery comes off the left sinus, the right coronary comes off the right sinus, and the remaining sinus is called the "noncoronary" sinus. The balloon-like shape of these sinuses allows blood to flow smoothly and help the valve close efficiently.

3. Sino-tubular Junction: This is the point where the aortic root transitions into the ascending aorta. Here, the sinuses come together and eventually form a cylinder. Many times, aneurysms in the root are continuous with aneurysms in the ascending aorta.

Dissections in the aortic root are particularly dangerous. Here, dissection may distort the aortic valve and cause sudden aortic regurgitation that can be life-threatening. The dissection can extend towards the heart and cause blood to surround and compress the heart within its sac, a phenomenon known as pericardial tamponade. The dissection can also involve the coronary arteries and cause poor blood flow, resulting in large myocardial infarction (aka a "heart attack").

The management of aortic root aneurysms involves careful monitoring for growth and surgical repair at a certain point. This usually involves either a Bentall procedure or a valve sparing root replacement (VSRR) in certain patients. The Bentall procedure replaces the aortic valve and the root, reimplanting the coronary arteries onto the new aortic root. The VSRR preserves the aortic valve and replaces the aneurysmal aortic root tissue around it, also requiring reimplantation of the coronary arteries.

Thanks again for joining us for Topic Tuesday! We hope to see you for the next one!

-Purab