Aneurysms that simultaneously involve the thoracic and abdominal aorta and/or those aneurysms including the visceral aortic segment are referred to as thoracoabdominal aortic aneurysms (TAAAs). Such aneurysms are uncommon, comprising no more than 2% to 5% of the total spectrum of degenerative aortic aneurysm. Studies examining natural history data for thoracic aortic aneurysms indicate that between 20% and 30% of patients will also be found to have aneurysms of the abdominal aorta. Successful management of abdominal aneurysm involving the visceral aortic segment was first performed by Etheredge in 1954. The modern era in TAAA management began with the pioneering work of E. Stanley Crawford, who described a simplified operative approach, the “clamp and sew” method, which also consisted of the inclusion technique wherein visceral and intercostal vessels were reconstructed from within the aneurysm by directly anastomosing openings in the main Dacron graft to the aortic origin of these vessels. Since graft replacement of TAAA implies at least temporary interruption of visceral and potentially spinal cord blood flow, operative management of these lesions may be complicated by ischemic damage in these vascular beds. Despite various surgical and adjunctive strategies applied in different centers to minimize overall operative morbidity, the state of the art in contemporary management of these patients still entails a 5% to 10% risk of perioperative mortality and/or morbidity in the form of renal, respiratory, and spinal cord ischemic complications (SCI). Efforts to supplant conventional open surgery with totally endovascular repair are as yet in their infancy, but can be anticipated to play an ever-increasing role.

The majority of TAAAs are degenerative in nature and occur in association with hypertension, smoking, and frequently with evidence of vascular disease in other territories. Up to 20% of TAAAs in most series are the sequelae of chronic aortic dissection; such patients are typically younger and may be afflicted with syndromic conditions such as Marfan’s syndrome. The male:female sex ratio of TAAAs in our patients is 1:1, whereas our experience with AAA patients is consistent with the 5 to 6:1 male:female sex ratio frequently reported in the literature. Others have noted the tendency for aneurysm disease in females to more often involve proximal aortic segments. Uncommon causes of TAAA include lesions that result from infection in a preexistent degenerative aneurysm or more commonly false aneurysm formation after infectious aortitis. Finally, a variety of congenital abnormalities, such as neurofibromatosis and/or the spectrum of vasculitis/aortitis syndromes can lead to TAAA; these typically constitute but 1% to 2% of cases.

Since the majority of patients seen for TAAA resection are those with degenerative aneurysms, demographic and clinical features typical of a patient population with diffuse atherosclerosis are the rule. Patients treated for degenerative aneurysm average 70 years in age and a history of hypertension is nearly universal. Cigarette smoking and/or significantCOPD is common, with 25% of patients having significant COPD as manifested by an FEV1 of less than 50% predicted. Cerebrovascular disease, prior stroke, and symptomatic manifestations of lower extremity arterial occlusive disease occur in 15% of patients. Associated visceral and/or renovascular occlusive disease occur to some degree in 30% of patients. Such lesions, of course, have direct implications for the technical conduct of the operation and the incidence and significance of chronic renal insufficiency. These patients are more likely to be older and to harbor some degree of renal function compromise; their overall incidence of complications after operation, in particular, renal failure, was significantly increased when compared with patients without visceral artery occlusive disease. The coexistence of renovascular disease and some degree of renal insufficiency is commonplace in TAAA patients and has important implications for accurate
assessment of perioperative risk and long-term preservation of renal function. With the exception of Type I TAAA, which frequently will terminate just proximal to the renal artery level, types II, III, and IV thoracoabdominal aneurysm designation implies aneurysmal degeneration of the entire visceral aortic segment. Some patients with renal insufficiency will have the potential for retrieval or salvage of renal function with renal artery reconstruction. We believe extreme levels of preoperative azotemia (serum creatinine greater than 2.5 cm/dL) constitute a relative contraindication to elective operation unless preoperative studies indicate some potential for salvage or retrieval of renal function with renal artery reconstruction.

Irrespective of the firm literature base against routine preoperative cardiac testing, all patients should be evaluated with physiologic testing to assess perioperative myocardial ischemic potential. In addition, patients with a history or symptoms suggestive of heart failure should have an assessment of left ventricular function. While patients with significant impairments of pulmonary reserve can usually be detected on a historical basis alone, we routinely obtain preoperative pulmonary function studies. Preoperative consultation with a pulmonologist for optimization of bronchodilator therapy and pulmonary toilet is an important component in the management of patients with significant COPD. However, institution of preoperative steroid therapy with the intent of improving respiratory function is contraindicated since we have observed this maneuver to precipitate aneurysm rupture. Advanced age is an important component only in as much as it is accompanied by overall fragility and impaired functional status.