A Case of Posterior Circulation Ischemic Stroke Caused by Heparin-Induced Thrombocytopenia after Detaining Hepatic Arterial Infusion Catheter

In Japan, hepatic arterial infusion chemotherapy (HAIC) using reservoir system is recommended for patients with hepatocellular carcinoma (HCC) whose hepatic spare ability is favorable. Arterial infusion catheter is commonly detained in hepatic artery via femoral or brachial artery. In our hospital, catheter is often inserted by puncturing the left subclavian or brachial artery considering the patient's activities of daily living (ADL) during long-term detaining. However, it rarely causes posterior circulation ischemic stroke because of the left vertebral artery branches on the path of catheter. We herein report a case of posterior circulation ischemic stroke caused by heparin-induced thrombosis (HIT) after detaining hepatic arterial infusion catheter. A 63-year-old man who is under HAIC treatment for HCC was introduced to the department of neurological surgery because of vertigo and vomiting. Magnetic resonance imaging revealed sporadic fresh cerebral infarction in the bilateral cerebellar hemisphere. Carotid ultrasonography detected a floating thrombus around the part of the left vertebral subclavian artery bifurcation. Detained catheter was removed and continuous heparin administration was started immediately. However, thrombocytopenia occurred 5 days after the injection. Because 4T's score was 6 points, HIT was strongly suspected. We stopped heparin injection immediately and observed the patient's physical status strictly. After that, platelet value improved naturally. At the late date, antibodies specific for platelet factor 4/heparin complexes were positive and he was diagnosed with HIT.