There is a general consensus that surgical treatment for thoracic aortic aneurysm should be undertaken if the diameter of the aneurysm exceeds 6-7cm. Other indications include rapidly enlarging aneurysms, severe aortic regurgitation or associated symptoms. In patients with Marfan Syndrome, there is a high risk of dissection and rupture, and surgical treatment should be selected when the aneurysm diameter reaches 5.5cm. Surgery for a thoracic aortic aneurysm entails resecting the aneurysm and replacing it with a suitably sized artificial vessel. Total cardiopulmonary bypass is necessary for ascending aortic aneurysm resection, and partial cardiopulmonary bypass to support blood circulation at the distal end of the aneurysm is reasonable for a descending aortic aneurysm resection. Aneurysms in the aortic arch can also be removed, but is a complex procedure as it requires the replantation of all the craniobrachial vessels in some patients.
About half of the patients with thoracic aortic aneurysm and three-fourths of the patients with healthy aortic aneurysm were eligible for aneurysm wrapping. Cystic aneurysms can sometimes be removed without the excision of the aorta. Furthermore, Dacron vascular replacement with artificial aortic valve and coronary artery replantation could be performed for the treatment of ascending aortic aneurysm involving the aortic annulus with aortic regurgitation.
For treatment of thoracic descending aortic aneurysm, a stent can be fixed using a percutaneous endovascular stent graft. This technique is far less traumatic than surgery and can reduce the possibility of paraplegia caused by the interruption of spinal artery blood supply in surgical treatment. Though the technique is still in the experimental stage, it is expected to play an important role in patients who cannot be treated surgically and are at risk of aneurysm rupture. The complications of atherosclerosis, such as myocardial infarction, cerebral infarction and renal failure, often occur under the intense physiological stress of surgery. The most common causes of early postoperative death are myocardial infarction, hemorrhage, respiratory failure, and infection. Advanced age, emergent surgery, prolonged aortic clamping, aneurysm expansion and intraoperative hypotension are the most important factors to determine perioperative mortality. Late postoperative mortality is often associated with cardiac complications and aneurysm rupture at the margins of the graft or other parts of the aorta.
The long-term efficacy of drug therapy for those with aneurysm expansion and associated significant atherosclerosis survivors has not been confirmed, but it has been reported that, in adult patients with Marfan syndrome, observe-blocking drugs have a definite effect, which can slow down the speed of aortic expansion, reduce the incidence of aortic dissection, aortic regurgitation and mortality. Patients with small thoracic aortic aneurysms during follow-up and those who have been surgically treated for thoracic aortic aneurysms can also reduce cardiorespiratory volume (dp/dt) and control blood pressure.
