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Page 2 of 24 Alberts et al. Vessel Plus 2023;7:34 https://dx.doi.org/10.20517/2574-1209.2023.37

ventricular and valve function, pericardial effusion, or other cardiac abnormalities. During cardiothoracic
surgery, transesophageal echocardiography (TEE) is used to confirm known or new pathology, asses heart
function, and to evaluate the effect of inotropic or fluid therapy. The use of TEE during cardiac surgery has
[1-3]
been shown to be associated with lower mortality and improved patient outcomes . Since the greater part
of the thoracic aorta can be well visualized by TEE, it proves to be an invaluable imaging tool in aortic
surgical procedures.

Technological developments in echocardiography have resulted in real-time, high-quality imaging and
precise measurement tools. With the introduction of special matrix array probes for three-dimensional (3D)
echocardiography in the late 2000s, it is possible to visualize structures in simultaneous multiplane modes
[4-6]
up to detailed real-time 3D images .

Although echocardiography operates with harmless ultrasound beams, TEE is categorized as a semi-invasive
imaging modality due to the insertion of the probe into the patient’s body. Nevertheless, several large
studies have shown that TEE is associated with a low incidence of complications (< 1.5%), of which the
majority are mild upper gastrointestinal complications such as dysphagia or gastric erosion [7-10] . Thus,
international guidelines state that TEE should be routinely used in adults without contraindications during
surgery on the thoracic aorta [11-14] .

Especially in the non-elective setting, surgery of the thoracic aorta is often high-risk surgery, associated with
significant blood loss, morbidity, and mortality. This requires optimal teamwork between the surgical,
perfusion, and anesthetic teams. For cardiac anesthesiologists, as well as cardiologists and cardiac surgeons,
a thorough understanding of the aspects of TEE is essential to guide the aortic procedure, evaluate surgical
repair, and screen for possible complications.

In this narrative review, we discuss the different aspects of the use of TEE during surgery of the aorta. We
start with a more technical part: The different parts of the thoracic aorta and how to visualize them.
Secondly, we address aortic diseases and their appearance on TEE. Finally, we discuss the use of TEE during
endovascular surgery of the thoracic aorta.

ANATOMY AND DEVELOPMENT OF THE AORTA
The thoracic aorta consists of the aortic root and a tubular part. The aortic root is a complex anatomic
structure, which includes the aortic valve annulus, leaflets, leaflets attachments, inter-leaflet triangles,
sinuses of Valsalva, and the sinotubular junction . It connects the heart to the systemic circulation and
[15]
gives rise to the coronary arteries. The coronary arteries originate at the left and right sinuses of Valsalva,
situated distal to the aortic valve.

The tubular part of the thoracic aorta consists of three segments. The ascending aorta originates at the
sinotubular junction and rises up to the brachiocephalic trunk.

The aortic arch begins at the brachiocephalic trunk and runs up to the left subclavian artery. In its course, it
gives rise to three branches. In the most common anatomic variant (approximately 80% of the population),
the branches of the aortic arch are the brachiocephalic artery, the left common carotid artery, and the left
subclavian artery [Figure 1]. In approximately 14% of the population, the left common carotid artery arises
from the brachiocephalic artery. In approximately 3% of the population, the left vertebral artery arises
directly from the aorta .
[16]