• Journal of Korean Neurosurgical Society
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• v.40 no.1
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• pp.28-30
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• 2006

Two patients presented with amaurosis fugax[AMF]. despite treatment with antiplatelet drugs and anticoagulants due to previous transient ischemic attacks. Angiography demonstrated severe stenosis in the cavernous and petrous internal carotid artery[ICA] respectively, with reduced flow in the ophthalmic artery[OA]. Endovascular stent placement in both patients resulted in normalization of the vessel lumen of the stenotic vessel segments. In addition, complete restoration of OA flow was noted immediately after stenting. Both patients showed no further episode of AMF over a follow-up period of 38 and 23 months respectively. Our clinical and angiographic findings suggest that hemodynamic Insufficiency in retinal vasculature caused by a stenosis of the cavernous or petrous ICA can be treated successfully by endovascular stent.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.48-50
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• 2014

A 70-year-old woman presented with headaches and recurrent stroke symptoms. During five years, the patient has been treated for cerebral infarction associated with severe atherosclerotic stenosis of the internal carotid artery. Three-year follow-up magnetic resonance angiography showed a tiny de novo aneurysm arising from the distal part of atherosclerotic internal carotid artery. And 5-year follow-up three-dimensional CT angiogram demonstrated a definite aneurysm enlargement as large as requiring treatment. During dissection of aneurysm, the oculomotor nerve was found to be penetrated with the growing de novo aneurysm. The authors report a case of a de novo aneurysm, which resulted from atherosclerotic stenosis of the internal carotid artery at the supraclinoid portion, that was found to be penetrating the oculomotor nerve with no ocular palsy.

• Investigative Magnetic Resonance Imaging
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• v.21 no.4
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• pp.242-251
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• 2017

Purpose: To investigate the association of carotid intraplaque hemorrhage (IPH) with acute cerebral ischemic events and progression of stenosis using magnetic resonance (MR) imaging. Materials and Methods: From April 2014 to December 2016, 53 patients underwent carotid plaque MR imaging, including magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) sequence. A total of 66 carotid arteries in 53 patients had carotid stenosis, and they were included in this study. Carotid arteries were classified according to the presence of IPH, the age of hemorrhage, and degree of stenosis. We assessed ipsilateral cerebrovascular event rates and progression of stenosis between the IPH and no-IPH groups. Results: Of the 61 carotid arteries assessed, 34 (56%) had IPH, and 27 (44%) had no IPH. Acute cerebral ischemic events were more frequent in the IPH group (47% vs. 22%, P = 0.045), especially in the < 30%-stenosis group (100% vs. 0%, P = 0.028). However, there was no significant difference in the incidence of ischemic events according to the age of hemorrhage (50% vs. 44%, P = 0.492). Among the 61 carotid arteries, 20 carotid arteries had previously undergone carotid artery imaging and were evaluated for plaque progression. The trend for progression of stenosis favored the IPH group versus the no-IPH group, with a marginal P-value ($20%{\pm}12.7$ vs. $9.6%{\pm}5.7$, P = 0.063). Conclusion: IPH was associated with an increased incidence of acute ischemic events, especially in the mild-stenosis group and it was also associated with progression of stenosis. Evaluation of the carotid IPH by carotid plaque MR could improve discrimination of carotid plaques that cause ischemic events and progression of stenosis.

• Journal of radiological science and technology
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• v.42 no.5
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• pp.351-356
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• 2019

This study aimed to determine whether there was a difference in measurements between North American Symptomatic Carotid Endarterectomy Trial(NASCET) and Warfarin-Aspirin Symptomatic Intracranial Disease(WASID) methods that measure the middle cerebral artery stenosis in Digital Subtraction Angiography (DSA) and Magnetic Resonance Angiography (MRA). It involved 24 patients who had completed both DSA and MRA among patients with Middle Cerebral Artery (MCA) stenosis. The Middle Cerebral Artery (MCA) stenosis was measured using the NASCET and WASID methods through a retrospective analysis. For the NASCET and WASID methods, they performed measurements on normal blood vessels located far from and close to the stenosis, respectively. The mean value and standard deviation of the Digital Subtraction Angiography (DSA) measured by the NASCET method were 59.23% and 13.27%. On the other hand, those of the Digital Subtraction Angiography (DSA) measured by the WASID method were 66.64% and 12.47%. And, the mean value and standard deviation of the Magnetic Resonance Angiography (MRA) measured by the NASCET method were 49.82% and 12.06%. By contrast, those of the Magnetic Resonance Angiography (MRA) measured by the WASID method were 56.63% and 10.67%. All the p-values obtained by the Pearson and Spearman correlation tests in the Digital Subtraction Angiography (DSA) and the Magnetic Resonance Angiography (MRA) were <0.01. In conclusion, this study suggests that both the NASCET and WASID methods to measure the middle cerebral artery stenosis in the Digital Subtraction Angiography (DSA) and the Magnetic Resonance Angiography (MRA) can be used if they are not used interchangeably.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.179-187
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• 2005

The characteristics of blood flow and the interaction between the blood vessel and blood flow play important roles in plaque cap rupture and the growth of atherosclerosis which may lead directly to a heart attack or a stroke. In this study, carotid arteries with different stenoses have been numerically simulated to investigate the wall shear stress(WSS) and the elastic motion of the vessel. Blood flow has been treated as physiological, laminar and incompressible flow. To model the shear thining behavior of the blood, the Carreau-Yasuda model has been employed but the viscoelasticity of blood has not been considered. The results show that the WSS of $severe(75\%)$ stenosis is much higher than those of $25\%\;and\;50\%$ stenosis in the region of stenosis. With the increase in the stenosis thickness, the expansion ratio of the center of the stenosis decreases while the expansion ratio of the upstream region of the stenosis increases.

• Korean Journal of Radiology
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• v.2 no.1
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• pp.52-56
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• 2001

Extracranial carotid artery dissection may manifest as arterial stenosis or occlusion, or as dissecting aneurysm formation. Anticoagulation and/or antiplatelet therapy is the first-line treatment, but because it is effective and less invasive than other procedures, endovascular treatment of carotid artery dissection has recently attracted interest. We encountered two consecutive cases of trauma-related extracranial internal carotid artery dissection, one in the suprabulbar portion and one in the subpetrosal portion. We managed the patient with suprabulbar dissection using a self-expandable metallic stent and managed the patient with subpetrosal dissection using a balloon-expandable metallic stent. In both patients the dissecting aneurysm disappeared, and at follow-up improved luminal patency was observed.

• Journal of Chest Surgery
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• v.39 no.11 s.268
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• pp.815-821
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• 2006

Background: Carotid endarterectomy is an effective treatment modality in patients with severe carotid artery stenosis, but it may result in serious postoperative complications, We analyzed the results of the carotid endarterectomy performed in our institution to reduce the complications related to the card endarterectomy. Material and Method: We analyzed retrospectively the medical records of 74 patients(76 cases) who underwent carotid endarterectomy for carotid artery stenosis by a single surgeon from February 1996 to July 2004. Result: There were 64 men and 10 women. The mean age of the patients was 63.6 years old. Carotid endarterectomy only was performed in 63 cases, carotid endarterectomy with patch angioplasty in 8 cases, and carotid endarterectomy with segmental resection of internal carotid artery and end to end anastomosis in 5 cases. Intra-arterial shunt was used in 29 cases. The mean back pressures of internal carotid arteries checked after clamping common carotid arteries and external carotid arteries were $23.48{\pm}10.04$ mmHg in 25 cases with changes in electroencephalography(group A) and $47.16{\pm}16.04$ mmHg in 51 cases without changes in electroencephalography(group B). There was no statistical difference in the mean back pressure of internal carotid arteries between two groups(p=0.095), but the back pressures of internal carotid arteries of all patients with changes in electroencephalography were under 40 mmHg. When there was no ischemic change of electroencephalography after clamping common carotid artery and external carotid artery, we did not make use of intra-arterial shunt regardless of the back pressure of internal carotid artery. Operative complications were transient hypoglossal nerve palsy in four cases, cerebral hemorrhage occurred at previous cerebral infarction site in two cases, mild cerebral infarction in one case, hematoma due to anastomosis site bleeding in one case, and upper airway obstruction due to laryngeal edema probably caused by excessive retraction during operation in two cases. One patient expired due to cerebral hemorrhage occurring at previous cerebral infarction site. Conclusion: Carotid endarterectomy is a safe operative procedure showing low operative mortality. We suggest that intra-arterial shunt usage should be decided according to the ischemic change of electroercephalography regardless of the back pressure of internal carotid artery. Excessive retraction during operation should be avoided to prevent upper alway obstruction due to laryngeal edema and if upper airway obstruction is suspected, prompt management is essential.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.456-461
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• 2018

Carotid artery stenting (CAS) has emerged as an alternative treatment for carotid stenosis in patients poorly suited for endarterectomy. Intracerebral hemorrhage following carotid revascularization (endarterectomy, angioplasty, artery stenting) is rare and thought to be related to reperfusion injury in most cases. Early experience suggests an increased incidence of hemorrhage following CAS as compared to endarterectomy. In this study, data were obtained through a case report on an 80-year-old male patient with cerebral infarction. The 80-year-old hypertensive man developed sudden monoparesis in the left arm. He underwent CAS for 90% stenosis of the left proximal internal carotid artery. Brain CT after procedure showed acute hematoma with left posterior cerebral artery territorial hemorrhage, including the upper thalamus with extended intraventricular hemorrhage (IVH). Since this hemorrhage occurred in vascular territory unlikely to have been supplied by the treated artery, this case suggests that the mechanism of intracerebral hemorrhage following CAS may in some cases be different from hyperperfusion hemorrhage classically described following endarterectomy.

• Journal of Korean Neurosurgical Society
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• v.47 no.6
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• pp.428-432
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• 2010

Objective : An effective intervention has not yet been established for patients with acute occlusion of the internal carotid artery (ICA). The aim of our study was to investigate the feasibility, safety, and efficacy of emergent stent placement of carotid artery to improve neurologic symptoms and clinical outcome. Methods : Of 84 consecutive patients with severe ICA stenosis who were admitted to our institution from March 2006 to May 2009, 10 patients with acute ICA occlusion (11.9%) underwent emergency carotid artery stent placement. We reviewed their records for neurologic outcome using the National Institutes of Health Stroke Scale (NIHSS) score, before and at 7 days after stent placement; clinical outcome using the modified Rankin Scale score (mRS) and Glasgow Outcome Scale (GOS); frequency of procedure-related complications; and recurrence rate of ipsilateral ischemic stroke within 90 days. Results : Carotid lesions were dilated completely in all patients. Median NIHSS scores before emergency stent placement and at 7 days were 16.6 and 6, respectively, showing significant improvement. Eight patients (80%) had favorable outcomes (mRS score 0-2 and GOS 4-5). Complications occurred in two patients (20%): stent insertion failed in one and an intracerebral hemorrhage occurred in the other. Ipsilateral ischemic stroke did not recur within 3 months. Conclusion : Emergency carotid artery stent placement can improve the 7-day neurologic outcome and the 90-day clinical outcome in selected patients with acute cerebral infarction.

• Journal of Korean Neurosurgical Society
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• v.56 no.5
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• pp.441-443
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• 2014

Cerebral hyperperfusion syndrome (CHS) is increasingly recognized as an uncommon, but serious, complication subsequent to carotid artery stenting (CAS) and carotid endarterectomy (CEA). The onset of CHS generally occurs within two weeks of CEA and CAS, and a delay in the onset of CHS of over one week after CAS is quite rare. We describe a patient who developed CHS three weeks after CAS with status epilepticus.