Anatomical predictors of difficult left internal carotid artery navigation in transradial access for neurointervention.

OBJECTIVE: Transradial access (TRA) has received considerable attention in the field of neurointervention owing to its advantages over transfemoral access. However, the difficulty of left internal carotid artery (ICA) navigation under certain anatomical conditions of the aortic arch and its branches is a limitation of right TRA. In this study the authors aimed to investigate the anatomical predictors that impede navigation of the left ICA in right TRA. METHODS: From January to October 2020, 640 patients underwent transradial angiography at a single institute. Among them, 263 consecutive patients who were evaluated by contrast-enhanced MRA before transradial angiography were included in the study and assigned to success or failure groups according to whether left ICA navigation was possible or not. Several anatomical predictors were investigated to evaluate the correlation of the success of left ICA navigation in right TRA. RESULTS: A higher grade of the aortic arch type (type I vs type III: OR 6.323, p = 0.0171), higher height of the right subclavian artery (OR 1.071, p = 0.0068), narrower turnoff angle of the left common carotid artery (CCA) (OR 0.953, p = 0.0017), wider distance between the innominate artery and the left CCA (OR 1.784, p < 0.0001), steeper angulation of the right subclavian artery (tortuous vs kinking: OR 6.323, p = 0.0066), and steeper angulation of the left CCA (normal vs tortuous: OR 7.453, p = 0.0087; normal vs kinking: OR 51.65, p < 0.0001) were significantly associated with successful navigation of the left ICA. The cutoff value of the height of the right subclavian artery, distance between the innominate artery and the left CCA, turnoff angle of the left CCA, and diameter of the left CCA were 54.83 mm, 4.25 mm, 17°, and 6.05 mm, respectively. CONCLUSIONS: Successful left ICA navigation in right TRA was related to the specific vascular geometry of the aortic arch and its branches. Preprocedural evaluation of the anatomical predictors identified in this study may enhance the success rate of left ICA navigation in right TRA.

Intracerebral Hemorrhage due to Thrombosis with Thrombocytopenia Syndrome after Vaccination against COVID-19: the First Fatal Case in Korea.

Vaccination with an adenoviral vector vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can result in the rare development of thrombosis with thrombocytopenia mediated by platelet-activating antibodies against platelet factor 4 (PF4). This is a life-threating condition that may be accompanied by bleeding due to thrombocytopenia with thrombosis of the cerebral venous sinus or splanchnic vein. Herein, we describe the first fatal case of thrombosis with thrombocytopenia syndrome in Korea, presenting with intracranial hemorrhage caused by cerebral venous sinus thrombosis. A 33-year-old Korean man received the first dose of the ChAdOx1 nCoV-19 vaccination. He developed severe headache with vomiting 9 days after the vaccination. Twelve days after vaccination, he was admitted to the hospital with neurological symptoms and was diagnosed with cerebral venous sinus thrombosis, which was accompanied by intracranial hemorrhage. Thrombocytopenia and D-dimer elevation were observed, and the result of the PF4 enzyme-linked immunosorbent assay antibody test was reported to be strongly positive. Despite intensive treatment, including intravenous immunoglobulin injection and endovascular mechanical thrombectomy, the patient died 19 days after vaccination. Physicians need to be aware of thrombosis with thrombocytopenia syndrome (TTS) in adenoviral vector-vaccinated patients. Endovascular mechanical thrombectomy might be a useful therapeutic option for the treatment of TTS with cerebral venous sinus thrombosis.

Clinical Utility of Angiographic CT with a Flat-detector Angiographic System during Endovascular Procedure.

OBJECTIVE: We evaluated the feasibility of angiographic computed tomography (ACT) for visualizing stent material in patients who underwent intracranial or extracranial stent placement to treat atherosclerotic lesions or stent assisted coil embolization. MATERIALS AND METHODS: We performed intrarterial and intravenous ACT on biplane angiography system equipped with flat panel detectors (Axiom Arits dBA; Siemens Medical Solutions, Forchheim, Germany). Vistipaque 320 was injected for contrast medium, total 150 mL at flow rate of 5 mL/s through artery and 77 mL at flow rate of 3.5 mL/s through vein. RESULTS: ACT is a new imaging modality that provides a clear visualization of stent strut. CONCLUSION: Therefore this new application has potential to become the noninvasive option for follow-up after endovascular surgery using stents.