Aortic Aneurysms An aneurysm is a widened and weakened part of a blood vessel. An aortic aneurysm is a bulge in the wall of the main blood vessel (aorta) that carries blood from your heart to your body. Baystate Health’s cardiovascular specialists have extensive experience treating aneurysms, and offer the latest in less invasive treatment options. There are two types of aortic aneurysms: Abdominal aortic aneurysms (AAA) occur in the part of the aorta that passes through your abdomen. If an AAA continues to grow without being treated, it may cause bleeding inside your body and possibly death. Thoracic aortic aneurysms (TAA) occur in the part of the aorta that passes through your chest. TAAs are less common than abdominal aneurysms and are typically treated surgically by cardiac surgeons.