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Biomedical subjects

Sun Yong Kim

Publications and source records attributed to Sun Yong Kim.

9 recordsLinked to original sources
PubMed2006

Stenting for vertebrobasilar dissection: a possible treatment option for nonhemorrhagic vertebrobasilar dissection.

INTRODUCTION: It has been reported that stent placement may improve compromised blood flow resulting from vertebrobasilar dissection. In this study the technical feasibility, safety, as well as short-term outcome of stent placement for the treatment of nonhemorrhagic vertebrobasilar dissection was retrospectively investigated. METHODS: Ten patients (eight men, two women; age range 36 to 45 years) with nonhemorrhagic vertebrobasilar dissection were treated by stenting. Nine lesions were located at the vertebral artery (VA) (one bilateral case) and two at the basilar artery. Seven patients presented with ischemic symptoms and three with headache. Among the nine VA dissections, eight lesions involved the posterior inferior cerebellar artery (PICA). Angiographic findings included abrupt or irregular vessel narrowing with aneurysmal dilatation in nine lesions and irregular bulbous aneurysmal dilatation in two lesions. RESULTS: Placement of a stent-within-a-stent was performed in six lesions and single stent in five lesions. Initial treatments were technically successful in all patients. Follow-up was performed using digital subtraction angiography (six patients) or CT angiography (two patients). Successful occlusion or decreased contrast filling of the aneurysm sac was noted in six patients (seven lesions), increased aneurysm sac filling in one patient, and parent artery occlusion in one patient. PICA flow was preserved in all those with follow-up (1 week to 17 months). CONCLUSION: Stent placement is technically feasible and safe for the treatment of vertebrobasilar artery dissection, especially for preserving PICA and/or major perforating arteries. However, a study with a larger population and longer follow-up is necessary for validation of the efficacy of this treatment modality.

Adult↗
PubMed2006

Comparison of spontaneous intracranial vertebral artery dissection with large artery disease.

OBJECTIVE: To compare clinical and angiographic characteristics and stroke patterns between spontaneous intracranial vertebral artery dissection (VAD) and vertebral large artery disease (LAD) (atherosclerosis). DESIGN: Retrospective study. SETTING: Tertiary referral center for cerebrovascular diseases. Patients Twenty-two patients with spontaneous VAD and 25 with LAD in the intracranial portion of the vertebral artery. MAIN OUTCOME MEASURES: We compared (1) clinical characteristics, including epidemiologic data, vascular risk factors including inflammatory markers, the presence of headache, and stroke syndromes and severity; (2) stroke pattern on diffusion-weighted imaging, which was classified as vertebral perforator infarct, basilar perforator infarct, small scattered infarct, large scattered infarct, and territorial infarct; and (3) angiographic findings, ie, the distribution of involved arteries, degree of stenosis, and the involvement on the anterior circulation and calcification of vertebral artery. RESULTS: Although patients with VAD were younger, and more often had headaches and fewer vascular risk factors than those with LAD (P<.01 in all cases), these clinical features were also observed in some LAD patients. Diffusion-weighted imaging data showed that vertebral perforator infarct and small scattered infarct were most common in the VAD group, while territorial infarct and large scattered infarct were most common in the LAD group (P = .02). On angiography, LAD more frequently had anterior circulation arterial involvement (P = .002), higher degree of stenosis (P = .002), and calcifications (P = .008). CONCLUSION: Our findings indicate that results of diffusion-weighted imaging and noninvasive vascular studies might provide clues to the clinical characteristics in differential diagnosis between VAD and LAD.

Aged↗
PubMed2006

Blood blister-like aneurysms at nonbranching sites of the internal carotid artery.

OBJECT: The clinical features of blood blister-like aneurysms (BBAs) that arise at nonbranching sites of the internal carotid artery (ICA) differ from those of saccular aneurysms. In this study, the authors attempt to describe optimal treatments for BBAs, which have yet to be clearly established. METHODS: Ten of 483 patients with aneurysmal subarachnoid hemorrhage who had been seen at the authors' institution between March 2001 and June 2005 had intraoperatively confirmed BBAs at nonbranching sites of the ICA. All ten patients were women between the ages of 37 and 64 years (mean age 49.3 years); five had a history of hypertension. The BBAs were localized to the right side of the ICA in seven cases. All patients were successfully treated; clipping was undertaken in six, clipping combined with wrapping in three, and trapping in one. These methods were used in conjunction with various other surgical techniques such as brain relaxation by draining cerebrospinal fluid, anterior clinoidectomy, exposing the cervical ICA, gentle subpial dissection (for aneurysms that adhered to the frontal lobe), complete trapping of the ICA before clipping, and protecting the brain. Clip slippage occurred at the end of dural closing in two cases; the aneurysm was completely obliterated using multiple clips combined with ICA stenosis in one of these cases and ICA trapping with good collateral flow in the other. An excellent clinical outcome was achieved in eight patients, whereas two patients were disabled from massive vasospasm. The authors retrospectively reviewed radiological and surgical data in all cases to determine which treatment methods produced a favorable outcome. CONCLUSIONS: Blood blister-like aneurysms located at nonbranching sites of the ICA are difficult to treat. Preoperative awareness and careful consideration of these lesions during surgery can prevent poor clinical outcomes.

Adult↗
PubMed2005

One-stage embolization in patients with acutely ruptured poor-grade aneurysm.

BACKGROUND: Early or ultra-early surgery for patients in poor neurological condition (Hunt and Hess grade IV or V) after ictus of aneurysmal subarachnoid hemorrhage is increasingly reported to prevent early rebleeding. To prevent any rebleeding after hospital admission, we have treated patients with poor-grade aneurysm during the same session as when diagnostic angiography is performed ("one-stage embolization"). The aim of the present study is to determine whether this treatment modality is a viable management option for this group of patients. METHODS: We retrospectively reviewed 18 consecutive patients who presented with acutely ruptured aneurysms and were in very poor neurological condition and who were treated with one-stage embolization. RESULTS: We observed 2 complications related to the endovascular procedure: partial occlusion of the parent artery and aneurysm rupture during the procedure. According to the Glasgow Outcome Scale, good recovery occurred in 8 patients, and moderate and severe disabilities occurred in 4 and 3 patients, respectively, and 3 patients died. No rebleeding occurred after the procedure. The mean follow-up of the surviving patients (those who were alive more than 30 days after embolization) was 13.7 months (4-25 months). Three patients had surgery after endovascular procedure: 2 surgical clipping of failed or partial aneurysm embolization and 1 emergency coil removal with clipping. A permanent ventriculoperitoneal shunt was placed in 11 patients. CONCLUSIONS: We achieved promising results by using one-stage embolization to prevent ultra-early rebleeding followed by aggressive resuscitation. The active involvement of the endovascular team from the stage of diagnostic angiogram is a prerequisite for this treatment strategy.

Acute Disease↗
PubMed2005

Ruptured aneurysm of the anomalous cerebellar artery originating from internal carotid artery presenting with carotid cavernous fistula: a case report.

We report a case of a ruptured aneurysm of the anomalous cerebellar artery originating from internal carotid artery presenting with a carotid cavernous fistula (CCF). An initial angiogram showed the typical appearance of a CCF with a direct fistulous tract with focal aneurysmal dilation from the ascending cavernous segment of the right internal carotid artery. A postembolization angiogram of the right internal carotid disclosed the anomalous cerebellar artery originating from the fistula point of the internal carotid artery.

Adult↗
PubMed2003

Inferring gene networks from time series microarray data using dynamic Bayesian networks.

Dynamic Bayesian networks (DBNs) are considered as a promising model for inferring gene networks from time series microarray data. DBNs have overtaken Bayesian networks (BNs) as DBNs can construct cyclic regulations using time delay information. In this paper, a general framework for DBN modelling is outlined. Both discrete and continuous DBN models are constructed systematically and criteria for learning network structures are introduced from a Bayesian statistical viewpoint. This paper reviews the applications of DBNs over the past years. Real data applications for Saccharomyces cerevisiae time series gene expression data are also shown.

Algorithms↗
PubMed2003

The role of transcranial Doppler in symptomatic striatocapsular small deep infarction.

BACKGROUND AND PURPOSE: The transcranial Doppler (TCD) findings in symptomatic small deep infarction are not well known. The aim of this study was to evaluate the role of TCD in striatocapsular small deep infarctions (SSDIs). METHODS: The cerebral angiography and TCD findings were analyzed on 100 patients with symptomatic cerebral infarcts on the middle cerebral artery (MCA) territory. The sensitivity, specificity, and accuracy of TCD in detecting the MCA lesions were compared between lacunar group (the patients with lacunar syndrome and SSDIs on magnetic resonance image) and nonlacunar group. RESULTS: Thirty-eight patients were classified as the lacunar group, whereas 62 patients as the nonlacunar group. On angiography, occlusive lesion of MCA was found in 18 of the lacunar group and 24 patients of the nonlacunar group. The degree of MCA stenosis was higher in the nonlacunar group (80.8% +/- 21.2%) than the lacunar group (60.4% +/- 21.6%). The accuracy of TCD for the detection of MCA stenosis was not different between the groups. However, the sensitivity of TCD in the lacunar group was lower (72%) than in the nonlacunar group (88%), and it might have been due to the difference in the degree of MCA stenosis among the groups. CONCLUSION: Occlusive lesions of the MCA should be considered as a potential cause of SSDIs. In this respect, TCD may be used for screening candidates for conventional angiography in those patients. High rate of mild-degree stenosis of MCA in patients with SSDIs, however, caused a risk for missing such stenosis on TCD.

Adult↗