Cerebral embolism of iodized oil (lipiodol) after transcatheter arterial chemoembolization for hepatocellular carcinoma.

Cerebral lipiodol embolism is a rare complication of transcatheter arterial chemoembolization (TACE). Its pathological mechanism remains ambiguous despite several investigations. In Case 1, a 67-year-old man with hepatocellular carcinoma (HCC) experienced neurological deficits soon after undergoing a fourth session of TACE. Computed tomography (CT) scan showed multiple hyperdense lesions along the gyrus of frontal lobes and in the subcortical white matter. Transcranial Doppler (TCD) and transesophageal echocardiogram performed during the intravenous injection of agitated saline documented the presence of a right-to-left shunt (RLS) by demonstrating microbubbles in the left middle cerebral artery and left atrium. In Case 2, a 63-year-old woman underwent a third TACE due to a large HCC. After the procedure, her mental status deteriorated. Brain CT showed multiple hyperdense lesions on the cerebral and cerebellar cortex. TCD with agitated saline showed multiple microembolic signals shortly after the injection of agitated saline. The risk of cerebral lipiodol embolism may increase with recurrence and progression of HCC in patients who have a pre-existing RLS in the heart or lung. A test for the detection of an RLS may be necessary to identify patients with a heightened risk of cerebral embolism when multiple TACE procedures are required. TACE for HCC can cause pulmonary embolism or infarction.(1,2) However, cerebral lipiodol embolism is rare after TACE. There have been several reports of cerebral embolism after TACE, but their exact mechanism has not yet been fully elucidated. We report herein 2 patients who developed cerebral lipiodol embolism after undergoing multiple TACE procedures for remnant HCC through a pre-existing RLS.