31: THORACIC AND THORACOABDOMINAL ANEURYSMS: OPEN REPAIR

PATIENT STORY

A 68-year-old man with hypertension and a history of smoking was 1 week post-op from a right total knee replacement. He presented to the emergency room with acute onset of shortness of breath and right leg swelling. A helical computed tomography (CT) scan of his chest showed a small subsegmental pulmonary embolus (PE) and deep venous thrombosis (DVT) of the right femoral vein. He was incidentally noted to have a 6.7-cm aneurysm of his thoracic aorta that involved the visceral segment (Figure 31-1). Given its size and the involvement of the visceral segment, an open repair was recommended.

HISTORY AND PHYSICAL EXAMINATION

• Most thoracoabdominal aortic aneurysms (TAAA) are asymptomatic at the time of diagnosis; however, most will become symptomatic before rupture.

• Much like abdominal aneurysms, they are diagnosed incidentally.

• The most common initial symptom is vague pain in the back, flank, chest, or even abdomen.

• The differential diagnosis is extensive in patients who present with these vague symptoms, and they may often be dismissed.

• Compressive symptoms may also occur.

  • Left recurrent laryngeal nerve causing hoarseness.

  • The aneurysm may compress the trachea or esophagus causing cough, dysphagia, or other associated symptoms.

  • Like abdominal aortic aneurysms, embolization to the visceral, renal, and lower extremity arteries has been reported.

• Unless there is an abdominal component to the TAAA there are no specific physical examination findings. If there is an abdominal portion, then a pulsatile mass may be present.

DIAGNOSTIC EVALUATION

• CT angiography is the mainstay of imaging modalities for evaluation of TAAAs.

  • Depending on the size and rate of growth, imaging for follow-up purposes is typically done at 6- to 12- month intervals.

  • While catheter-directed aortography historically was the modality of choice, helical CT angiography is the current modality of choice.

  • Currently angiography is used for special situations such as mapping the spinal cord circulation or concurrent occlusive disease in the head and neck vessels.

  • CT angiography allows for reconstructed views of the aorta (Figure 31-1) as well as examination of other organs in the chest, abdomen, and pelvis, which occasionally will reveal incidental pathology.

  • CT angiography, like conventional angiography, can also aid in operative planning by identifying large intercostal arteries as well as mural thrombus, inflammatory changes, and other anatomic features that would affect operative planning (Figures 31-1 and 31-2).