Case Report: Intra-procedural fatal cerebral lipiodol embolism without angiographically visible shunting during right inferior phrenic artery TACE.

BACKGROUND: CLE can occur during right inferior phrenic artery TACE despite negative angiographic findings. Negative angiography should not be interpreted as excluding occult embolic pathways, and radiologic clearance of intracranial Lipiodol should not be equated with neurological recovery. CASE PRESENTATION: A 51-year-old man with clinically diagnosed malignant liver tumor who developed fatal CLE during the fourth liver-directed procedure. During selective right inferior phrenic artery transarterial chemoembolization (TACE), angiography showed hepatic-dome tumor staining. While the iodized-oil emulsion was being injected, the awake patient abruptly developed bilateral limb weakness that progressed to complete loss of limb strength and impaired consciousness. Cranial CT performed immediately after symptom onset showed multiple hyperdense intracranial lesions that largely disappeared on virtual non-contrast images, supporting iodized-oil deposition. MRI-DWI demonstrated multifocal acute ischemic lesions in bilateral supratentorial and infratentorial territories, while MRA showed no major intracranial arterial occlusion. Follow-up CT on postoperative days 1 and 3 showed progressive clearance of intracranial Lipiodol deposits, but the ischemic lesions and severe neurological deficits persisted, and death was confirmed. This temporal-imaging-outcome sequence shows that radiologic Lipiodol clearance does not necessarily indicate neurological reversibility once widespread acute ischemic injury has occurred. CONCLUSION: CLE can occur during right inferior phrenic artery TACE despite negative angiographic findings. Negative angiography should not be interpreted as excluding occult embolic pathways, and radiologic clearance of intracranial Lipiodol should not be equated with neurological recovery.