Anatomy-Lexicon

Aortic root

What is the aortic root?

The aortic root is a small section of our main artery (aorta). The aorta begins at the heart and then arches through the chest and abdomen, where it supplies blood to various organs.

The aortic root is the first section of the ascending main artery (Ascending aorta), which is only a few inches long. This part of the aorta begins at the left ventricle and extends vertically upwards for a few centimeters until it reaches the aortic arch (Arcus aortae) opens.

The function of the aortic root is the so-called Windkessel function, which ensures a continuous flow of blood. Diseases of the aortic root, such as an aneurysm, go unnoticed for a long time until they finally lead to life-threatening complications.

Anatomy of the aortic root

The aortic root is the first section of the main artery (aorta). The main artery can be divided into an ascending section (Ascending aorta), an aortic arch (Arcus aortae) and a descending section (Descending aorta) subdivide. The aortic root describes the first short section of the ascending part of the aorta and thus marks the transition between the heart and the aorta.

The ascending aorta begins in the left ventricle and rises a few centimeters vertically until it joins the aortic arch. Due to the close proximity to the heart, the aortic root lies completely in the pericardial cavity (Pericardium).

The aortic valve is located at the origin of the aortic root (Valva aortae). This heart valve opens when the heart muscle contracts and pumps blood into the circulation (Systole).

However, the aortic valve also has an important function when it is closed. During the relaxation of the heart muscle, it prevents (diastole) the return of blood to the left ventricle.

Another structure that is part of the aortic root is the aortic bulb (Aortic bulb). This is a bulbous extension at the origin of the aorta. It consists of three small rooms (Aortic sinus) formed by the aortic wall and the leaflets of the aortic valve. The coronary vessels go from two of these spaces (Coronary arteries), which supply the heart muscle with blood.

Are you interested in other sections of the aorta? Read more about this under: Aorta - Anatomy, Function & Diseases

Function of the aortic root

The aortic root is the first part of the aorta that extends out of the left ventricle. The blood ejected in the systole thus first reaches the aortic root and from there flows further into the ascending aorta, the aortic arch and the descending aorta.

The aortic root takes on more than the function of carrying the blood. The blood is ejected from the left ventricle in bursts with each heartbeat. However, it is necessary that the blood flows continuously and at a constant speed in the vessels. The aortic root takes on this task.

In contrast to other sections of the aorta, its vascular wall consists of a particularly large number of elastic fibers. These stretch when the blood is pumped out of the heart. In this way they store the blood that is thrown out in spurts for a very short time.

This elastic part of the main artery contracts again between two heartbeats, so that the temporarily stored blood is continuously forwarded into the aortic arch. This wind chamber function of the aorta near the heart converts the pulsating blood flow into a continuous flow.

This Windkessel function decreases with age and deteriorates in particular due to arteriosclerotic changes in the arteries. This ultimately leads to increased stress on the left heart and can lead to heart problems.

For a better overview of the anatomy and function of the cardiovascular system, Dr-Gumpert's team has provided lay-understandable pictures for you: Illustration of the aorta

What is the normal diameter of the aortic root

There is no standard value for the diameter of the aortic root that can be used as a benchmark for all people. This is because every person has a certain height and body surface area, which have an influence on the diameter of the aortic root.

The reference range is the indication that the aortic root should not be larger in diameter than between 20mm and 37mm. However, a change in the main artery is always individualized with the help of imaging (e.g. Sonography) and various measured values.

As soon as a deviation from the normal values has been determined, this is checked at certain time intervals and, if necessary, an indication for surgery is given.

Aortic root diseases

Aortic root aneurysm

An aneurysm is a pathological enlargement of a vessel that affects all three wall layers. An aortic root aneurysm describes this vascular sac in the area of the aortic root. In relation to all aneurysms of the aorta, the bulges in the upper part of the main artery only account for a small proportion.

The abdominal aortic aneurysm (BAA) and mainly older men are affected. This particular group of patients can be explained by typical risk factors such as:

high nicotine consumption
high blood pressure
arteriosclerosis

Another less common cause are various connective tissue diseases such as Marfan's syndrome. Here, the connective tissue, including that in the vessels, is particularly elastic, so that such people tend to develop aneurysms.

An aortic root aneurysm shows rather unspecific symptoms, if any, such as fatigue and decreased performance. An aortic root aneurysm leads to aortic regurgitation in the long term, as blood repeatedly flows back into the left ventricle through the bulge. This damages the aortic valve and loses its closing function. This ultimately leads to left heart strain.

An aneurysm is identified by imaging such as sonography or computed tomography (CT), ascertained and monitored. It mainly depends on the diameter of the bulge and its size progression (Increase in size) on. Surgery is recommended for aneurysms larger than 55mm or rapidly increasing in diameter.

The gold standard in the surgical treatment of an aortic root aneurysm is the insertion of a tubular or Y-prosthesis. However, various stent prostheses can also be used to shut off the aneurysm and restore the normal vascular lumen.

Dilatation of the aortic root

Dilation of the aortic root describes a pathological expansion of the aortic root. Risk factors that promote dilatation of the main artery include:

high nicotine consumption
arteriosclerosis
high blood pressure

However, there are also congenital diseases, such as Marfan's syndrome, that lead to weakness in the vascular walls. Unfortunately, the symptoms of an enlarged aortic root are very unspecific, and those affected often notice a reduction in performance and increased fatigue.

The easiest way to dilate the aortic root is to use an ultrasound (Sonography) can be determined. Depending on gender, body size and body surface, values between 20mm and 36mm are physiological.

Depending on the extent of the aortic root, either regular follow-up checks are carried out or the indication for surgical intervention is made.

Aortic root ectasia

Ectasia is a pathological protrusion of a hollow organ that can also affect a vessel. The ectasia of the aortic root describes a permanent expansion of the aortic root, whereby the individual wall layers of the vessel are intact. The bulge (Dilation) can vary in size.

Nowadays the terms “ectasia” and “aneurysm” are often used equivalently in medicine to describe a pathological enlargement of a vessel. It has become common to use the term "ectasia" for minor bulges.

The standard values for the diameter of the aortic root are gender-specific and also depend on the body size and surface area. The critical limit from which an operation is urgently indicated is a diameter of over 55mm or a ruptured sac.

If you are still interested in other aortic diseases, read our next article below: Diseases of the aorta