Free-floating thrombus in the internal carotid artery is rare, its incidence is unknown and its management remains controversial. It is usually diagnosed by angiography after a symptomatic ischemic cerebral event. Moreover, neurological disorders such as the initial manifestation of type A aortic dissection become more difficult to diagnose. We describe ischemic stroke caused by thromboembolism with free-floating thrombus in the internal carotid artery due to type A aortic dissection. Neurological manifestations of common carotid artery dissection, including transient ischemic attack and cerebral infarction, occur in 2.7% - 7% of patients with aortic dissection . Cerebral infarction could be due to common carotid occlusion or artery-to-artery embolism from a thrombus on the intimal surface of the dissected artery. However, whether the mechanism of brain ischemia associated with aortic dissection is hemodynamic ischemia or thromboembolism remains unclear. Therefore, emergency surgical intervention for acute type A aortic dissection complicated by stroke remains controversial. However, when dissection involves the carotid arteries and compromises brain perfusion, flow can only be re-established within a short therapeutic window in the setting of acute stroke. Several investigators have reported favorable outcomes of the immediate surgical repair of acute type A dissection complicated by cerebral malperfusion . However, several patients even in their series developed postoperative neurological deterioration and eventual cerebral death. The effects of cardiopulmonary bypass and reperfusion on the ischemic brain have not been elucidated. The optimal method of protecting the brain during aortic arch surgery for patients with cerebral malperfusion remains unclear. Estrera and associates reported 19% and 50% operative mortality and neurological recovery rates, respectively, among 16 patients after aortic repair under profound hypothermic arrest and retrograde cerebral perfusion . Pocar and associates reported 0% mortality and an 80% neurological recovery rate for comatose patients who underwent surgery with ASCP . Several factors, including the time to treatment, collateral circulation, extent of ischemia, and stroke subtype, might influence the response to reperfusion. Our patient already had a large free-floating thrombus in the right internal carotid artery before surgery. The natural history of free-floating thrombus in the carotid artery is unknown.
Last date updated on June, 2014