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.

[3] 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.

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.

[7] Open surgery typically involves exposure of the dilated portion of the aorta and insertion of a synthetic (Dacron or Gore-Tex) graft (tube).

[11] This technique leaves the branches of the aorta un-perfused during the time it takes to sew in the graft, potentially increasing the risk of ischemia to the organs which derive their arterial supply from the clamped segment.

[12] In infrarenal aneurysms, the relative tolerance of the lower extremities to ischemia allows surgeons to clamp distally with low risk of ill effect.

[14] In OAS for infra-renal aneurysms, the abdominal aorta is anastomosed preferentially to the main limb of a tube or bifurcated graft in an end-to-end fashion to minimize turbulent flow at the proximal anastomosis.

OAS is widely recognized as having higher rates of perioperative morbidity and mortality than endovascular procedures for comparable segments of the aorta.

For patients unable to undergo major surgery, the outcome of conservative approach remains uncertain but usually provides for life-long suppressive antibiotic therapy.

[19] Open repair for thoracoabdominal aneurysms requires a very large incision that cuts through muscles and sometimes bones making recovery very difficult and painful for the patient.

By the mid-1960s, at Baylor College of Medicine, DeBakey’s group began performing surgery on thoracoabdominal aortic aneurysms (TAAA), which presented formidable surgical challenges, often fraught with serious complications, such as paraplegia, paraparesis and renal failure.

In 1992, another classification, Extent V, characterized by Hazim J. Safi, MD, identified aneurysmal disease extending from the sixth intercostal space to above the renal arteries.

Safi's group used experimental animal models for a prospective study on the use distal aortic perfusion, cerebrospinal fluid drainage, moderate hypothermia and sequential clamping to decrease in the incidence of neurological deficit.

[24] However, with evolving surgical strategies, identification of predictors, and use of various adjuncts over the years, the incidence of spinal cord injury after thoracic/thoracoabdominal aortic repair has declined.