Open aortic surgery

Open aortic surgery (OAS), also known as open aortic repair (OAR), describes a technique whereby an abdominal, thoracic or retroperitoneal surgical incision is used to visualize and control the aorta for purposes of treatment, usually by the replacement of the affected segment with a prosthetic graft. OAS is used to treat aneurysms of the abdominal and thoracic aorta, aortic dissection, acute aortic syndrome, and aortic ruptures.

Aortobifemoral bypass is also used to treat atherosclerotic disease of the abdominal aorta below the level of the renal arteries. In 2003, OAS was surpassed by endovascular aneurysm repair (EVAR) as the most common technique for repairing abdominal aortic aneurysms in the United States.

Depending on the extent of the aorta repaired, an open aortic operation may be called an Infrarenal aortic repair, a Thoracic aortic repair, or a Thoracoabdominal aortic repair. A thoracoabdominal aortic repair is a more extensive operation than either an isolated infrarenal or thoracic aortic repair.

OAS is distinct from aortic valve repair and aortic valve replacement, as OAS describes surgery of the aorta, rather than of the heart valves. When the aortic valve is diseased in addition to the ascending aorta, the Bentall procedure is used to treat the entire aortic root. An axillary-bifemoral bypass is another type of vascular bypass used to treat aortic pathology, however it is not true open aortic surgery as it reconstructs the flow of blood to the legs from the arm, rather than in the native location of the aorta.

Open aortic surgery (OAS) is used to treat patients with aortic aneurysms greater than 5.5 cm in diameter, to treat aortic rupture of an aneurysm any size, to treat aortic dissections, and to treat acute aortic syndrome. It is used to treat infrarenal aneurysms, as well as juxta- and pararenal aneurysm, thoracic and thoracoabdominal aneurysms, and also non-aneurysmal aortic pathology. Disease of the aorta proximal to the left subclavian artery in the chest lies within the specialty of cardiac surgery, and is treated via procedures such as the valve-sparing aortic root replacement.

Prior to the advent of endovascular aneurysm repair (EVAR), OAS was the only surgical treatment available for aortic aneurysms. The shift away from open aortic surgery towards endovascular surgery since 2003 has been driven by worse perioperative mortality associated with OAS, particularly in patients in relatively frail health. Unlike endovascular repair, there are no strict anatomic contra-indications to open repair; Rather, open repair is viewed as the fall back option for patients with unfavorable anatomy for endovascular repair. The main drawback of open repair is the larger physiologic demand of the operation, which is associated with increased rates of short term mortality in most studies.

OAR is still preferred to EVAR at some institutions and by some patients as it may be more durable than EVAR, and does not require post-operative surveillance CT scans.

Patients younger than 50 years with descending and thoracoabdominal aortic aneurysm have low surgical risks, and open repairs can be performed with excellent short-term and durable long-term results. Open surgical repairs should be considered initially in younger patients requiring descending and thoracoabdominal aortic aneurysm repairs. Heritable thoracic aortic disease (HTAD) warrants closer postoperative surveillance.