• Journal of Korean Neurosurgical Society
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• v.44 no.3
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• pp.159-162
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• 2008

Stenting is a useful alternative treatment modality in carotid artery stenosis patients who are too high-risk to undergo carotid endarterectomy (CEA). We report a case of contralateral cerebral infarction after stenting for extracranial carotid stenosis. A 78-year-old woman was admitted to the hospital with left-sided weakness. Based on magnetic resonance imaging (MRI) of the brain and conventional angiography, she was diagnosed with an acute watershed infarct of the right hemisphere secondary to severe carotid stenosis. Stenting was performed for treatment of the right carotid artery stenosis after a one-week cerebral angiogram was completed. Thirty minutes after stent placement, the patient exhibited a generalized seizure. Four hours later, brain MRI revealed left hemispheric cerebral infarction. Complex aorta-like arch elongation, tortuosity, calcification, and acute angulation at the origin of the supra-aortic arteries may increase the risk of procedural complications. In our case, we suggest that difficult carotid artery catheterization, with aggressive maneuvering during stenting, likely injured the tortuous, atherosclerotic aortic arch, and led to infarction of the contralateral cerebral hemisphere by thromboemboli formed on the wall of the atherosclerotic aorta.

• Journal of Chest Surgery
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• v.33 no.9
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• pp.748-751
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• 2000

The diffuse form of supravalvar aortic stenosis represents a surgical challenge when the ascending aorta, aortic arch, proximal descending thoracic aorta and arch arteries are involved. It can be treated by a variety of surgical approaches. We report a case of severe diffuse supravalvar aortic stenosis combined with an aortic valve anomaly and occlusion of the right coronary artery ostium in a 14-year-old boy with Williams syndrome. We enlarged the aortic root(Nick's procedure), ascending aorta, aortic arch, proximal descending thoracic aorta, and innominate artery with patches and replaced aortic valve with 19 mm St. Jude valve. Deep hypothermic circulatory arrest and retrograde cerebral perfusion were used during repair of the arch and arch artery.

• Journal of Chest Surgery
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• v.27 no.5
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• pp.394-398
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• 1994

Takayasu`s arteritis is one of chronic inflammatory disease characteristically involving the aorta and it`s major branches. We experienced two surgical cases of Takayasu`s arteritis associated with the stenosis of the descending thoracic aorta. One case was 15 year-old girl and she was admitted because of dyspnea on exertion for 12 months. Aortogram showed the stenosis of the descending thoracic aorta from just below left subclavian artery to the 9th thoracic vetebra. The other case was 10 year-old girl and she was admitted because of URI and hypertension. Aortogram showed narrowing of right innominate artery, but developed collateral circulation, and the stenosis of the descending thoracic aorta near the 9th thoracic vertebra. In each case, bypass graft from the ascending aorta to the abdominal aorta just above the inferior mesenteric artery was performed with satisfactory result.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.105-110
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• 2008

Renovascular hypertension results from a lesion that impairs blood flow to a part of or all, of one or both kidneys. Renal artery stenosis is the major cause of renovascular hypertension and the most common cause of treatable secondary hypertension. Recently, percutaneous transluminal renal angioplasty(PTRA) with or without stent placement, has become the preferred choice for correcting symptomatic renal artery stenosis since it is less invasive than surgical reconstruction. PTRA with balloons designed for the dilatation for the dilatation of the coronary artery can be tried in small sized renal artery stenosis. We report a case of renovascular hypertension in a 13-year-old male who had small sized renal artery stenosis. Hypertension was controlled by PTRA with balloon dilatation.

• Korea-Australia Rheology Journal
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• v.16 no.2
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• pp.101-108
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• 2004

The hemodynamics behavior of the blood flow is influenced by the presence of the arterial stenosis. If the stenosis is present in an artery, normal blood flow is disturbed. In the present study, the characteristics of pulsatile flow in the blood vessel with stenosis are investigated by the finite volume method. For the validation of numerical model, the computation results are compared with the experimental ones of Ojha et al. in the case of 45％ stenosis with a trapezoidal profile. Comparisons between the measured and the computed velocity profiles are favorable to our solutions. Finally, the effects of stenosis severity and wall shear stress are discussed in the present computational analysis. It can be seen, where the non-dimensional peak velocity is displayed for all the stenosis models at a given severity of stenosis, that it is exponentially increased. Although the stenosis and the boundary conditions are all symmetric, the asymmetric flow can be detected in the more than 57％ stenosis. The instability by a three-dimensional symmetry-breaking leads to the asymmetric separation and the intense swirling motion downstream of the stenosis.

• Korea-Australia Rheology Journal
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• v.21 no.2
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• pp.119-126
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• 2009

A numerical analysis is performed to investigate the effect of rotation on the blood flow characteristics with four different angular velocities. The artery has a cylindrical shape with 50% stenosis rate symmetrically distributed at the middle. Blood flow is considered a non-Newtonian fluid. Using the Carreau model, we apply the pulsatile velocity profile at the inlet boundary. The period of the heart beat is one second. In comparison with no-rotation case, the flow recirculation zone (FRZ) contracts and its duration is reduced in axially rotating artery. Also wall shear stress is larger after the FRZ disappears. Although the geometry of artery is axisymmetry, the spiral wave and asymmetric flow occur clearly at the small rotation rate. It is caused that the flow is influenced by the effects of the rotation and the stenosis at same time.

• The Journal of Internal Korean Medicine
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• v.38 no.6
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• pp.1096-1100
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• 2017

The carotid artery is one of the main vessels supplying blood to the brain. Carotid artery stenosis is mostly caused by atherosclerosis, a disease where cholesterol is deposited in the arterial blood vessels. Tremor refers to rhythmic shaking of a body part. Tremor is a symptom of many diseases, including Parkinson's disease, essential tremor, orthostatic tremor, cerebellar disease, peripheral neuropathy, and alcohol withdrawal. Tremors may be classified as postural, rest, and action tremors. Tremor of a patient with stenosis of the left carotid artery decreased with acupuncture treatment. The acupoints were GB20, TE17, GV8 and GV11. This case shows that the acupuncture treatment is effective against tremor.

• Journal of Chest Surgery
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• v.25 no.3
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• pp.307-314
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• 1992

The internal mammary artery has been advocated for use in bypass grafting owing to its superior long-term patency when compared to saphenous vein grafts. Concern exists that the flow through internal mammary artery may be inadequate during periods of peak myocardial demand when the internal mammary artery graft was used for proximal left anterior descending artery stenosis. This flow adequacy was investigated in 13 consecutive patients with a mean proximal left anterior descending artery stenosis of 84.2% who were selected for coronary bypass using internal mammary artery. We checked flow and diameter of left internal mammary artery without intraluminal dilatation just before anastomosis to left anterior descending artery during cardiopulmonary bypass. Clinical results were evaluated postoperatively with clinical symptoms, echocardiographies, stress tests, and coronary angiographies. The mean internal mammary artery flow measured just before anastomosis was 38ml/ min[range of 20 to 80ml /min] and its mean internal diameter 1.4mm. Maximal workload was improved from preoperative value of 6.3$\pm$2.5METS to postoperative value of 9.1$\pm$1.4 METS in 9 patients who Paired-test can be used. Cardiac symptoms recurred in two patients after bypass surgery, but they were not related to left internal mammary artery grafts. All patients were discharged in postoperatively 9.3 days[range of 7 to 20 days] after operation without mortality. Thus, on the basis of these findings, the internal mammary artery is a reasonable graft that we can routinely use for proximal left descending artery stenosis if internal diameter of the internal mammary artery is more than 1.0mm and its flow is more than 20ml /min at mean arterial pressure of 50 to 60mmHg during cardiopulmonary bypass.

• Korean Journal of Radiology
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• v.24 no.8
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• pp.784-794
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• 2023

Objective: To determine whether dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) can be used to evaluate posterior cerebral circulation in pediatric patients with moyamoya disease (MMD) who underwent anterior revascularization. Materials and Methods: This study retrospectively included 73 patients with MMD who underwent DSC perfusion MRI (age, 12.2 ± 6.1 years) between January 2016 and December 2020, owing to recent-onset clinical symptoms during the follow-up period after completion of anterior revascularization. DSC perfusion images were analyzed using a dedicated software package (NordicICE; Nordic NeuroLab) for the middle cerebral artery (MCA), posterior cerebral artery (PCA), and posterior border zone between the two regions (PCA-MCA). Patients were divided into two groups; the PCA stenosis group included 30 patients with newly confirmed PCA involvement, while the no PCA stenosis group included 43 patients without PCA involvement. The relationship between DSC perfusion parameters and PCA stenosis, as well as the performance of the parameters in discriminating between groups, were analyzed. Results: In the PCA stenosis group, the mean follow-up duration was 5.3 years after anterior revascularization, and visual disturbances were a common symptom. Normalized cerebral blood volume was increased, and both the normalized time-topeak (nTTP) and mean transit time values were significantly delayed in the PCA stenosis group compared with those in the no PCA stenosis group in the PCA and PCA-MCA border zones. TTP_PCA (odds ratio [OR] = 6.745; 95% confidence interval [CI] = 2.665-17.074; P < 0.001) and CBV_PCA-MCA (OR = 1.567; 95% CI = 1.021-2.406; P = 0.040) were independently associated with PCA stenosis. TTP_PCA showed the highest receiver operating characteristic curve area in discriminating for PCA stenosis (0.895; 95% CI = 0.803-0.986). Conclusion: nTTP can be used to effectively diagnose PCA stenosis. Therefore, DSC perfusion MRI may be a valuable tool for monitoring PCA stenosis in patients with MMD.

• Journal of Chest Surgery
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• v.35 no.1
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• pp.20-26
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• 2002

Background: Due to the concern of flow competition or retrograde steal, it has been generally suggested that the right gastroepiploic artery(RGEA) pedicled graft should be used in critical coronary stenosis lesion. The study was designed to evaluate the potential of retrograde flow competition in the RGEA pedicled graft by measuring the native pressure differences(PD) between the normal coronary artery and celiac arterial pressure, which would be compared with trans-stenosis pressure gradients(TSPG) in coronary artery occlusive disease. Material and Method: Between July, 1998 and February, 1999, pressures of the right coronary artery and the right gastroepiploic artery(or the celiac artery) were measured in patients with the patent right coronary artery(n=12). The PD between the arteries was compared with the TSPG in the occlusive coronary arteries(n=32). Result: The pressures of the normal right coronary artery and celiac artery were 143$\pm$23 vs. 134$\pm$17mmHg in systole(p<0.005), 74$\pm$13 vs. 73$\pm$14mmHg in diastole(p=NS), and 100$\pm$16 vs. 97$\pm$15mmHg in mean (p<0.05). The PD between the arteries were -8~25mmHg in systole, -4~7mmHg in diastole, and -1~10mmHg in mean. The TSPG measured in the occlusive coronary arteries were -4~19(7$\pm$5.8)mmHg in the lesion less than 75% stenosis vs. 7~74(27$\pm$18.3)mmHg in the 75% or over stenosis lesion(p<0.005). The normally existing pressure difference between the coronary arteries and RGEA(15~20mmHg) was significantlyless than the TSPG in .the occlusive coronary artery with 75% or over stenosis(p<0.001). Conclusion: If the pressure gradient between the RGEA and the coronary artery distal to the stenosis is the main determinant of development of retrograde flow competiton in the RGEA pedicled graft, the above data suggests that there will be little chance of competition when It is used in the coronary lesion with 75% or over stenosis.