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 enzymelinked 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.

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 enzymelinked 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.

A case of stacked coin ingestion mistaken for button battery

Button battery ingestion requires emergency endoscopic removal since severe complications, such as esophageal perforation, can develop within 4 hours of the ingestion. Given that guardians do not witness the children’s foreign body ingestion 40% of the time, physicians can only guess what was swallowed based on plain radiography. We report a case of a 45-month-old-boy who visited the emergency department after swallowing an unknown foreign body and whose radiographs showed “circle-within-a-circle appearance” on the anteroposterior view and “step-off appearance” on the lateral view, suggesting button battery ingestion. We conducted emergency endoscopic removal, and found stacked coins mimicking a button battery on the radiographs. The coins were pushed into the stomach and came out through defecation 3 weeks later without further complications. Distinguishing between stacked coins and a button battery through radiography may help avoid unnecessary emergency endoscopy.

Clinical Results of the Intra-Arterial Thrombolysis with Stent Retriever Device Weather Perfusion Diffusion Mismatching and Intravenous Tissue Plasminogen Activator Administration

OBJECTIVE: Intraarterial thrombolysis (IA-Tx) with stent retriever is accepted as an additional treatment for selected patients and the clinical benefit is well reported. Each intravenous tissue plasminogen activator administration (IV-tPA) and perfusion diffusion mismatching (P/D-mismatching) is well known the beneficial effects for recanalization and clinical outcomes. In this report, authors analyzed the clinical outcomes of additional IA-Tx with retrieval stent device, according to the combined IV-tPA and P/D-mismatching or not. METHODS: Eighty-one treated IA-Tx with the Solitaire stent retriever device, diagnosed as anterior circulation larger vessel occlusion were included in this study. Computed tomography-angiography (CTA) was done as an initial diagnostic image and acute stroke magnetic resonance image (MRI) followed after the IV-tPA. Forty-two patients were in the tPA group and 39 patients were in the non-tPA group. Recanalization rate, clinically significant hemorrhagic (sICH) and clinical outcomes were recorded according to the IV-tPA and P/D-mismatching. RESULTS: Recanalization rate was 81.0% in IV-tPA group, and it was 69.2% in non-tPA group (p = 0.017). While sICH were 19.9% and 25.6%, respectively (p = 0.328). Neurologic outcomes did not influence by IV-tPA administration or not. But according to the P/D-mismatching, the recanalization rate and sICH were 91.9% and 16.7% in the mismatched group and 46.7% and 46.7% in the matched group (p = 0.008 and p = 0.019, respectively). CONCLUSION: For patients treated with IA-Tx with retrieval stent, IV-tPA infusion does not influence on the sICH, recanalization rate and neurologic outcomes. But P/D-mismatching was correlated well with sICH, recanalization rate and clinical outcomes.

Pipeline Embolization Device for Large/Giant or Fusiform Aneurysms: An Initial Multi-Center Experience in Korea / 신경중재치료의학

PURPOSE: The purpose of this study was to assess the safety and early outcomes of the Pipeline device for large/giant or fusiform aneurysms. MATERIALS AND METHODS: The Pipeline was implanted in a total of 45 patients (mean age, 58 years; M:F=10:35) with 47 large/giant or fusiform aneurysms. We retrospectively evaluated the characteristics of the treated aneurysms, the periprocedural events, morbidity and mortality, and the early outcomes after Pipeline implantation. RESULTS: The aneurysms were located in the internal carotid artery (ICA) cavernous segment (n=25), ICA intradural segment (n=11), vertebrobasilar trunk (n=8), and middle cerebral artery (n=3). Procedure-related events occurred in 18 cases, consisting of incomplete expansion (n=8), shortening-migration (n=5), transient occlusion of a jailed branch (n=3), and in-stent thrombosis (n=2). Treatment-related morbidity occurred in two patients, but without mortality. Both patients had modified Rankin scale (mRS) scores of 2, but had an improved mRS score of 0 at 1-month follow-up. Of the 19 patients presenting with mass effect, 16 improved but three showed no changes in their presenting symptoms. All patients had excellent outcomes (mRS, 0 or 1) during the follow-up period (median, 6 months; range, 2-30 months). Vascular imaging follow-up (n=31, 65.9%; median, 3 months, range, 1-25 months) showed complete or near occlusion of the aneurysm in 24 patients (77.4%) and decreased sac size in seven patients (22.6%). CONCLUSION: In this initial multicenter study in Korea, the Pipeline seemed to be safe and effective for large/giant or fusiform aneurysms. However, a learning period may be required to alleviate device-related events.

Perfusion-Weighted MRI Parameters for Prediction of Early Progressive Infarction in Middle Cerebral Artery Occlusion

OBJECTIVE: Early progressive infarction (EPI) is frequently observed and related to poor functional outcome in patients with middle cerebral artery (MCA) infarction caused by MCA occlusion. We evaluated the perfusion parameters of magnetic resonance imaging (MRI) as a predictor of EPI. METHODS: We retrospectively analyzed patients with acute MCA territory infarction caused by MCA occlusion. EPI was defined as a National Institutes of Health Stroke Scale increment ≥2 points during 24 hours despite receiving standard treatment. Regional parameter ratios, such as cerebral blood flow and volume (rCBV) ratio (ipsilateral value/contralateral value) on perfusion MRI were analyzed to investigate the association with EPI. RESULTS: Sixty-four patients were enrolled in total. EPI was present in 18 (28%) subjects and all EPI occurred within 3 days after hospitalization. Diabetes mellitus, rCBV ratio and regional time to peak (rTTP) ratio showed statically significant differences in both groups. Multi-variate analysis indicated that history of diabetes mellitus [odds ratio (OR), 6.13; 95% confidence interval (CI), 1.55-24.24] and a low rCBV ratio (rCBV, <0.85; OR, 6.57; 95% CI, 1.4-30.27) was significantly correlated with EPI. CONCLUSION: The incidence of EPI is considerable in patients with acute MCA territory infarction caused by MCA occlusion. We suggest that rCBV ratio is a useful neuro-imaging parameter to predict EPI.

Treatment of the Superior Sagittal Sinus Thrombosis with the Mechanical Thrombectomy Using Stent-Retriever Device

Cerebral venous sinus thrombosisis an uncommon entity and its clinical presentations are highly variable. We present the case of superior sagittal sinus thrombosis. Although it was medical refractory, successfully treated with mechanical thrombectomy using the Solitaire FR device. A 27-year-old man who presented with venous infarction accompanied by petechial hemorrhage secondary to the superior sagittal sinus (SSS) thrombosis. Due to rapid deterioration despite of anticoagulation therapy, the patient was taken for endovascular treatment. We deployed the Solitaire FR device (4×20 mm) in the anterior portion of the thrombosed SSS, and it was left for ten minutes before the retraction. Thus, we removed a small amount of thrombus. But the sinus remained occluded. We therefore performed the thrombectomy using the same methods using the Solitaire FR (6×20 mm). Thus, we were successful in removing larger clots. Our case highlights not only that the mechanical thrombectomy using the Solitaire FR is effective in achieving revascularization both rapidly and efficiently available, but also that it might be another option in patients with cerebral venous sinus thrombosis who concurrently had rapid clinical deterioration with devastating consequences.

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.

Trans-radial Carotid Artery Stenting in a Patient with Abdominal Aortic Occlusion

We report transradial access (TRA) for emergency carotid artery stenting (CAS) as a useful alternative when the femoral artery cannot be accessed. A 63-year-old man arrived at our emergency room 30 minutes after left hemiplegia and loss of consciousness. Brain computed tomography (CT) anigograpy showed occlusion of the right interntal carotid artery (ICA) and CT perfusion revealed delayed time-to-peak in the territory of the middle cerebral artery. For, endovascular treatment, trans-femoral access (TFA) was attempted but failed due to occlusion of the abdominal aorta. So, we changed access route via radial artery and confirmed proximal ICA dissection. CAS was attempted via TRA and it was successfully performed. Final angiography showed recanalization of ICA and patient was clinically improved.

Management of Asymptomatic Carotid Stenosis for Primary Stroke Prevention: 2012 Focused Update of Korean Clinical Practice Guidelines for Stroke

Extracranial carotid stenosis is a well-established, modifiable risk factor for stroke. Asymptomatic extracranial carotid stenosis is increasingly being detected due to the introduction of less-invasive and more-sensitive advanced diagnostic technologies. For severe asymptomatic stenosis, earlier pivotal clinical trials demonstrated the benefit of carotid endarterectomy over the best medical therapy. Since then, great advances have been made in interventional and medical therapies as well as surgical techniques. The first edition of the Korean Stroke Clinical Practice Guidelines for primary stroke prevention for the management of asymptomatic carotid stenosis reflected evidences published before June 2007. After the publication of the first edition, several major clinical trials and observational studies have been published, and major guidelines updated their recommendation. Accordingly, the writing group of Korean Stroke Clinical Practice Guidelines (CPG) decided to provide timely updated evidence-based recommendations. The Korean Stroke CPG writing committee has searched and reviewed literatures related to the management of asymptomatic carotid stenosis including published guidelines, meta-analyses, randomized clinical trials, and nonrandomized studies published between June 2007 and Feb 2011. We summarized the new evidences and revised our recommendations. Key changes in the updated guidelines are the benefit of intensive medical therapy and further evidence of carotid artery stenting as an alternative to carotid endarterectomy. The current updated guidelines underwent extensive peer review by experts from the Korean Stroke Society, Korean Society of Intravascular Neurosurgery, Korean Society of Interventional Neuroradiology, Korean Society of Cerebrovascular Surgery, and Korean Neurological Association. New evidences will be continuously reflected in future updated guidelines.

Focused Update of 2009 Korean Clinical Practice Guidelines for the Surgical or Interventional treatment of Extracranial Carotid Artery Stenosis in Secondary Prevention of Stroke / 대한뇌졸중학회지

Since the publication of the first edition of Korean clinical practice guidelines of secondary stroke prevention, encouraging data from recent large clinical trials and meta-analysis have led us to consider many therapeutic options in the treatment of symptomatic extracranial carotid stenosis. Accordingly, the writing group of Clinical Research Center for Stroke decided to provide recent views on the therapeutic revascularization of extracranial carotid stenosis, and timely evidence-based recommendations. In this updated version, new evidences about carotid angioplasty/stenting, treatment timing, and perioperative preparation are given, and qualifying conditions for operator are elucidated. This refinement was based on current consensus between Korean Society of Intravascular Neurosurgery, Korean Society of Interventional Neuroradiology, and Korean Society of Cerebrovascular Surgery and approved by Korean Stroke Society, Korean Neurological Association, and Korean Society of Geriatric Neurology. These recommendations are subject to future correction based on new evidences from ongoing and future studies.

Primary Thoracic Epidural Melanoma : A Case Report

A 68-year-old woman with progressive paraparesis and altered sensation lasting approximately five days was admitted to our clinic. Magnetic resonance imaging (MRI) revealed an advanced stage T7-8 epidural mass ventral to the spinal cord, which was believed to be a metastatic tumor considering the patient's age. A highly enhanced epidural mass and pedicle appeared during the MR scan. However, the pathologic findings were compatible with the diagnosis of a primary meningeal melanocytic tumor. Primary epidural melanomas are extremely rare lesions. This case was finally diagnosed as a primary thoracic spinal epidural melanoma.

Is Transradial Cerebral Angiography Feasible and Safe? A Single Center's Experience

OBJECTIVE: Although a transradial angiography is accepted as the gold standard for cardiovascular procedures, cerebral angiography has been performed via transfemoral approach in most institutions. The purpose of this study is to present our experience concerning the feasibility, efficacy, and safety of a transradial approach to cerebral angiography as an alternative to a transfemoral approach. METHODS: Between February 2007 and October 2009, a total of 1,240 cerebral angiographies were performed via a transradial approach in a single center. The right radial approach was used as an initial access route. The procedure continued only after the ulnar artery was proven to provide satisfactory collateral perfusion according to two tests (a modified Allen's test and forearm angiography). RESULTS: The procedural success rate was 94.8% with a mean duration of 28 minutes. All supra-aortic vessels were successfully catheterized with a success rate of 100%. The success rates of selective catheterization to the right vertebral artery, right internal carotid artery, left internal carotid artery, and left vertebral artery were 96.1%, 98.6%, 82.6% and 52.2%, respectively. The procedure was performed more than twice in 73 patients (5.9%), including up to 4 times in 2 patients. The radial artery occlusion was found in 4 patients (5.4%) on follow-up cerebral angiography, but no ischemic symptoms were observed in any of the cases. CONCLUSION: This study suggests that cerebral angiography using a transradial approach can be performed with minimal risk of morbidity. In particular, this procedure might be useful for follow-up angiographies and place less stress on patients.

Changes in Bypass Flow during Temporary Occlusion of Unused Branch of Superficial Temporal Artery

OBJECTIVE: Some neurosurgeons intentionally ligate the branches of the superficial temporal artery (STA) that are not used in standard STA-to-middle cerebral artery (MCA) anastomosis for the purpose of improving the flow rate in the bypass graft. We investigated changes in bypass flow during temporary occlusion of such unused branches of the STA. METHODS: Bypass blood flow was measured by a quantitative microvascular ultrasonic flow probe before and after temporary occlusion of branches of the STA that were not used for anastomosis. We performed measurements on twelve subjects and statistically assessed changes in flow. We also examined all the patients with digital subtraction angiography in order to observe any post-operative changes in STA diameter. RESULTS: Initial STA flow ranged from 15 mL/min to 85 mL/min, and the flow did not change significantly during occlusion as compared with pre-occlusion flow. The occlusion time was extended by 30 minutes in all cases, but this did not contribute to any significant flow change. CONCLUSION: The amount of bypass flow in the STA seems to be influenced not by donor vessel status but by recipient vessel demand. Ligation of the unused STA branch after completion of anastomosis does not contribute to improvement in bypass flow immediately after surgery, and furthermore, carries some risk of skin necrosis. It is better to leave the unused branch of the STA intact for use in secondary operation and to prevent donor vessel occlusion.

Unexpected Complication of Intravenous Recombinant Tissue Plasminogen Activator Thrombolysis in a Patient with Acute Ischemic Stroke: Aortic Dissection / 대한뇌혈관외과학회지

We report here on a case of acute aortic dissection after intravenous tissue plasminogen activator (t-PA) administration in a patient with acute ischemic stroke. A 75-year-old woman with a history of hypertension and diabetes mellitus presented with left hemiplegia and a decreased mentality. The admission studies revealed severe stenosis of the right middle cerebral artery and decreased cerebral perfusion. Initial chest radiography showed hypertensive cardiovascular changes and increased interstial markings on both lung fields. Cyanosis and cardiac arrest occurred 80 minutes after intravenous t-PA administration. Emergency cardiopulmonary resuscitation was done and chest CT showed a dissection involving the whole aorta and pericardial effusion due to bleeding. In spite of our earnest efforts, the patient died. It should be kept in mind that aortic dissection can occur after intravenous t-PA administration and an early clinical suspicion and diagnosis is needed to avoid this devastating complication.

Spontaneous Bilateral Basal Ganglia Hemorrhage: Case Report / 대한뇌혈관외과학회지

A 39-year old man presented with comatose mentality. Brain computerized tomography revealed bilateral basal ganglia hemorrhage. The amount of hematoma was 35 cc each. He had no hypertension history through out regular health examination. Emergenct hematoma evacuation was performed. Histopathologic study disclosed no evidence of amyloid angiopathy or infection. He died 4 days after the operation due to myocardiac infarction. This report describe a rare case of simultaneous bilateral cerebral hemorrhages without history of hypertension.

Comparative Study of Cerebral Vasospasm between Endovascular Treatment and Conventional Surgery of Acutely Ruptured Aneurysms: Clinical Study / 대한뇌혈관외과학회지

OBJECT: Generally, it seems like that the incidence of vasospasm of vasospasm in endovascular coil embolization is higher than clipping in aneurysmal subarachnoid hemorrhage. But endovascular coil embolization in our study group was not associated with higher incidence of symptomatic vasospasm than direct clipping and we made an analysis of that cause. METHODS: The authors reviewed 220 patients with aneurysmal subarachnoid hemorrhage who had been treated with either neck clipping or coil embolization by a single surgeon between January 1997 and December 2002. Poor initial grade (Hunt & Hess grade IV & V) patients were excluded. Finally 171 patients were enrolled in this study. 126 patients(74%) underwent direct surgical clipping and 45 patients (26%) underwent endovascular treatments of their aneurysms. RESULTS: Overall symptomatic vasospasm occurred in 32 (19%) patients, 4 of 45 patients (9%) were coiling group and 28 of 126 (22%) were surgically treated group. There was no difference between two groups in age, initial Hunt & Hess grade, Glasgow coma scale, operation time, treatment initiation time, patient's medical status. CONCLUSIONS: Patients who underwent coil embolization were not more likely to suffer from symptomatic vasospasm than aneurysm neck clipping in better clinical grades (Hunt & Hess grade of I to III) patients in our institute.

Usefulness of Drug-Eluting Stents in Angioplasty and Stenting of the Vertebral Artery Origin : Comparison with Bare Stents: Clinical Research / 대한뇌혈관외과학회지

OBJECT: In the treatment of coronary atherosclerosis, drug-eluting stents are effective in decreasing the rate of major adverse cardiac events and angiographic restenosis compared with bare metal stents. However, the benefits and safety of using these new devices in the cerebral vasculature have not been evaluated. To assess the effectiveness of drug-eluting stents in the cerebral vasculature, the authors analyzed clinical and angiographic results after percutaneous transluminal angioplasty and stenting in patients with vertebral artery origin stenosis. METHODS: Ninety-one patients with 99 vertebral origin stenoses treated with percutaneous endovascular balloon angioplasty and stent placement during a period of 5.1 years (September 1999-October 2004). Follow-up angiograms were obtained from 38 patients with 42 lesions (24 men, 14 women ; mean age, 61.9 yrs ; mean follow-up period, 9.1 months). We reviewed the clinical and radiological records of these patients. RESULTS: Bare stents were implanted in 30 lesions, while drug-eluting stents were implanted in 12 lesions, with a mean residual stenosis of 5.1 %. The overall rate of moderate-to-severe restenosis (> or =50%) was 31.0 % (13 of 42 cases). The restenosis rate in the bare stent group was 36.7 %, compared with 16.7 % in the drug-eluting stent group (p=0.282). Comparing the restenosis rate in stented lesions with reference diameters less than 3.5 mm (11 with bare stents, 12 with drug-eluting stents), the restenosis rates were 63.6 % in the bare stent-group and 16.7 % in the drug-eluting stent-group (p=0.029). CONCLUSION: Drug-eluting stents placed in vertebral artery origin stenosis have lower restenosis rate than bare stents, particularly in small-sized vessels.

Comparative Study of Cerebral Vasospasm between Endovascular Treatment and Conventional Surgery of Acutely Ruptured Aneurysms: Clinical Study / 대한뇌혈관외과학회지

OBJECT: Generally, it seems like that the incidence of vasospasm of vasospasm in endovascular coil embolization is higher than clipping in aneurysmal subarachnoid hemorrhage. But endovascular coil embolization in our study group was not associated with higher incidence of symptomatic vasospasm than direct clipping and we made an analysis of that cause. METHODS: The authors reviewed 220 patients with aneurysmal subarachnoid hemorrhage who had been treated with either neck clipping or coil embolization by a single surgeon between January 1997 and December 2002. Poor initial grade (Hunt & Hess grade IV & V) patients were excluded. Finally 171 patients were enrolled in this study. 126 patients(74%) underwent direct surgical clipping and 45 patients (26%) underwent endovascular treatments of their aneurysms. RESULTS: Overall symptomatic vasospasm occurred in 32 (19%) patients, 4 of 45 patients (9%) were coiling group and 28 of 126 (22%) were surgically treated group. There was no difference between two groups in age, initial Hunt & Hess grade, Glasgow coma scale, operation time, treatment initiation time, patient's medical status. CONCLUSIONS: Patients who underwent coil embolization were not more likely to suffer from symptomatic vasospasm than aneurysm neck clipping in better clinical grades (Hunt & Hess grade of I to III) patients in our institute.

Usefulness of Drug-Eluting Stents in Angioplasty and Stenting of the Vertebral Artery Origin : Comparison with Bare Stents: Clinical Research / 대한뇌혈관외과학회지

OBJECT: In the treatment of coronary atherosclerosis, drug-eluting stents are effective in decreasing the rate of major adverse cardiac events and angiographic restenosis compared with bare metal stents. However, the benefits and safety of using these new devices in the cerebral vasculature have not been evaluated. To assess the effectiveness of drug-eluting stents in the cerebral vasculature, the authors analyzed clinical and angiographic results after percutaneous transluminal angioplasty and stenting in patients with vertebral artery origin stenosis. METHODS: Ninety-one patients with 99 vertebral origin stenoses treated with percutaneous endovascular balloon angioplasty and stent placement during a period of 5.1 years (September 1999-October 2004). Follow-up angiograms were obtained from 38 patients with 42 lesions (24 men, 14 women ; mean age, 61.9 yrs ; mean follow-up period, 9.1 months). We reviewed the clinical and radiological records of these patients. RESULTS: Bare stents were implanted in 30 lesions, while drug-eluting stents were implanted in 12 lesions, with a mean residual stenosis of 5.1 %. The overall rate of moderate-to-severe restenosis (> or =50%) was 31.0 % (13 of 42 cases). The restenosis rate in the bare stent group was 36.7 %, compared with 16.7 % in the drug-eluting stent group (p=0.282). Comparing the restenosis rate in stented lesions with reference diameters less than 3.5 mm (11 with bare stents, 12 with drug-eluting stents), the restenosis rates were 63.6 % in the bare stent-group and 16.7 % in the drug-eluting stent-group (p=0.029). CONCLUSION: Drug-eluting stents placed in vertebral artery origin stenosis have lower restenosis rate than bare stents, particularly in small-sized vessels.