The aorta is the main blood vessel that exits the heart to supply blood to the rest of the body. It is shaped like a 'question mark': extends up, gives off branches to the brain and arms before looping down the back and head towards the lower body.
Thoracic (chest) aneurysms can occur anywhere along the aorta (the main blood vessel that exits the heart to provide blood to the entire body). Most occur in the area closest to the heart, usually called the ‘ascending aorta’. This is our largest artery, and it is largest as it immediately exits the heart and tapers down in size throughout the body as it gives off branches. Anatomically, the aorta can be divided into segments.
The aortic root is the portion that immediately exits the heart, and comprises some very important structures, namely, the aortic valve and both main coronary artery origins. The aortic root is a complex structure with three bulges, called sinuses of Valsalva, each corresponding to an aortic valve leaflet, and two of which usually contain the origins of the left and right main coronary arteries. Because of this unique anatomy, when aneurysms occur in the root, they are more complicated than aneurysms elsewhere along the aorta. Aortic root replacement requires not only replacement of the aneurysm (with a polyester tube using cardiopulmonary bypass), but also, either replacement (Bentall Procedure) or re-implantation of the aortic valve (“David Procedure”) and the coronary artery origins. Click here to see a video of a David Procedure.
The ascending, or ‘tubular’ ascending begins where the aortic root ends, at an anatomic ridge that is narrower than the aortic root, and completely circular, called the sin tubular junction. This portion of the aorta extends to the segment just before the first arch vessel arises to give blood to the brain and right arm. Aneurysm repair is accomplished by replacing the dilated (aneurismal) section with a polyester tube. Coming soon: an ascending aneurysm video.
Ascending aneurysms may extend into the proximal (first segment of) the aortic arch, which also makes treatment more complicated. These aneurysms require special cardiopulmonary bypass techniques in order to replace the aneurysm while preserving blood flow to the brain due to the proximity to the aortic arch vessels.
Aneurysms that primarily occur in the last segment of the aortic arch and first portion of the descending thoracic aorta can often be treated with less invasive strategies, including hybrid procedures and endografting (stent repair), rather than traditional ‘open’ heart surgery, and without utilization of cardiopulmonary bypass.
Thoracic aneurysms can occur alone in any of the described segments, or in combination. When in combination, they are usually contiguous, i.e. aortic root and ascending aneurysm, or ascending and proximal arch aneurysm. It is currently unknown whether or not multi-level involvement is an adverse risk factor for aortic events, and this is another concentration of clinical research in the TABAV Program at Valley.