Aneurysm is a condition that forms a bulge in the aorta, which is the largest blood vessel in the heart. This blood vessel is responsible for carrying oxygen-rich blood from the heart to various parts of the body. There are two types of aneurysms- abdominal aneurysm and thoracic aneurysm. If an aneurysm occurs in the ascending part of the aorta, which is closest to the heart, it is called the thoracic ascending aortic aneurysm.