Open surgery: Your doctor makes an incision in the chest to replace the weak part of the thoracic aorta. The incision depends on the location of the thoracic aneurysm. The incision is made in the front of the chest if the aneurysm is in the aortic arch. The incision is made on the left side of your chest for an aneurysm in the descending thoracic aorta. Your surgeon then replaces the weak part of the thoracic aorta with a graft. The graft is stronger than the aorta and supports it, allowing blood to flow seamlessly.