Balloon-like Mobile Plaque in the Innominate Artery: Ultrasonographic and Pathological Perspectives of Repetitive Embolism.

Mobile plaque in the innominate artery is extremely rare and difficult to diagnose, especially in its acute stage. Its diagnosis is often delayed in many cases, resulting in delayed treatment and poor prognosis. Herein, we report the case of a 69-year-old patient with multiple cerebral infarction only in the right internal carotid artery and vertebrobasilar territories. No embolic sources were found until arterial ultrasonography detected a large balloon-like mobile plaque in the IA. Mobile plaque consisted of high-and low-echoic components and showed balloon-like plaque. Despite sufficient antiplatelet therapy, recurrence of cerebral embolism could not be prevented. IA replacement was eventually performed by cardiac surgeons. Pathological examinations showed that organized mobile plaque could have existed previously and acute thrombi, generated after the atheromatous plaque rupture caused by the mechanical burden of organized mobile plaque, could expand along with the organized mobile plaque and caused balloon-like plaque and related with repeated embolism. The IA should be explored immediately in cases of repetitive right-sided cerebral embolisms to prevent further recurrence.