Risk factors for the neurologic complications associated with aortic aneurysms

We reviewed the incidence of neurologic complications in 200 consecutive patients with aortic aneurysm or aortic dissection. In this 2-year period, neurologic impairment developed in 18.5% of these patients, and in 10 patients neurologic dysfunction heralded aortic rupture or dissection. Those patients with abnormal neurologic examinations at presentation frequently had aneurysm rupture or dissection and a mortality rate of 54%. Patients with thoracic or thoracoabdominal aneurysms were more likely to have neurologic complications than those with abdominal aneurysms. The most common complications were focal central nervous system ischemia, followed by disorders of consciousness and peripheral nerve complications. In patients who had elective aneurysm resection, female sex, aneurysm location, and intraoperative hypotension were risk factors for focal central nervous system ischemia. We conclude that neurologic complications depend on aneurysmal location, occur at various levels of the nervous system, and frequently develop when the intraoperative mean arterial pressure falls below 55 mm Hg.