Publications by authors named "Hyun Seung Kang"

Background And Objectives: The role of bypass surgery in intracranial atherosclerotic steno-occlusive diseases (ICADs) remains controversial. We aimed to analyze the surgical outcomes of bypass surgery in patients with the ICADs in a single tertiary institution.

Methods: Among 1018 cases of low-flow bypass surgery between 2003 and 2022, 215 patients with the ICAD refractory to medical treatment were finally enrolled in this study.

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The necessity of bilateral bypass in adult moyamoya disease (MMD) remains unclear despite its recommendation for pediatric and hemorrhagic cases. We aimed to investigate the natural course of hemodynamically stable unoperated hemispheres after bypass surgery for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD. Among 288 patients, the mean age at the first operation of the unstable hemispheres was 40.

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Vein of Galen aneurysmal malformation is one of important pediatric arteriovenous shunt diseases, especially among neonates and infants. Here, early history of the disease identification, basic pathoanatomy with a focus on the embryonic median prosencephalic vein, classification and differential diagnoses, and recent genetic studies are reviewed.

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Objective: Chronic subdural hematomas (cSDHs) are generally known to result from traumatic tears of bridging veins. However, the causes of repeat spontaneous cSDHs are still unclear. We investigated the changes in vasculature in the human dura mater and outer membrane (OM) of cSDHs to elucidate the cause of their spontaneous repetition.

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Background: Precommunicating (P1) segment aneurysms of the posterior cerebral artery are rare, with few studies reported to date. Herein, we address the clinical and radiologic outcomes of their endovascular treatment.

Methods: For this study, we retrieved prospectively collected data on 35 consecutive patients with 37 P1 aneurysms, analyzing the clinical ramifications and morphologic outcomes of treatment.

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Article Synopsis
  • There is limited research on the link between cerebral hyperperfusion syndrome (CHS) and blood-brain barrier (BBB) disruption in humans, prompting a study to explore this association post-bypass surgery in patients with cerebrovascular diseases.
  • The study involved 36 patients, analyzing changes in brain perfusion and permeability using advanced MRI techniques at different stages: pre-surgery, post-surgery, and discharge.
  • Findings indicated that in CHS patients, specific perfusion and permeability metrics significantly changed post-surgery, suggesting that BBB disruption may play a role in the development of CHS following the surgical procedure.
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Few risk factors for the development of intracranial aneurysms (IAs) are known. We investigated the potential role of thyroid diseases in IA development using nationwide real-world data. A nested case-control study within the National Health Insurance Service-National Sample Cohort data from 2002 to 2019 was performed.

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Objective: Much emphasis has been put on the use of antiplatelet medication for the prevention of ischemic events in the treatment of cerebral aneurysms with stent assistance. In this regard, the effectiveness and safety of a low-dose prasugrel regimen during the periprocedural period was recently reported. The purpose of this study was to present the outcomes of patients on low-dose prasugrel regimens during the follow-up period after stent-assisted coil embolization (SACE) of cerebral aneurysms.

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Introduction: A proper stratification of intracranial aneurysms is critical in identifying rupture-destined aneurysms and unruptured intracranial aneurysms. We aimed to determine the utility of geometric and hemodynamic indexes in differentiating two types of aneurysms and to examine the characteristics of natural evolutionary changes of unruptured aneurysms.

Methods: Rupture-destined aneurysm refers to an aneurysm that undergoes subsequent aneurysmal subarachnoid hemorrhage (SAH).

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Article Synopsis
  • Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) has high mortality and poor functional outcomes, prompting the need for effective bundled treatments introduced in 2017 to improve patient conditions.
  • A study comparing 90 patients revealed that those receiving bundled treatments had significantly better functional outcomes and lower mortality rates after 6 months compared to those receiving conventional care.
  • The research concluded that bundled treatments, along with initial pupil reflex presence, are strongly associated with improved long-term outcomes in patients suffering from poor-grade aSAH.
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Article Synopsis
  • A genome-wide association study (GWAS) was conducted to identify genetic factors linked to adult moyamoya disease (MMD) in a Korean population, involving 216 patients and 296 controls using a specialized genetic array.
  • The analysis identified 21 significant single-nucleotide polymorphisms (SNPs), particularly in the 17q25.3 region, which includes genes such as RNF213, associated with a higher risk for MMD.
  • The study suggests that mutations in RNF213 are potential biomarkers for assessing susceptibility to MMD in Koreans, offering insights that could help in clinical evaluations of the disease.
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Objective: Preoperative transarterial embolization (TAE) of tumor feeders in hypervascular spine metastasis is known to reduce intraoperative estimated blood loss (EBL) during surgery. The effect of TAE varies for several reasons, and one controllable factor is the timing between embolization and surgery. However, the adequate timing remains unclear.

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Objective: Little is known about the relationship between postoperative changes in cerebral perfusion and the ivy sign representing leptomeningeal collateral burden in moyamoya disease (MMD). This study aimed to investigate the usefulness of the ivy sign in evaluating cerebral perfusion status following bypass surgery in patients with adult MMD.

Methods: Two hundred thirty-three hemispheres in 192 patients with adult MMD undergoing combined bypass between 2010 and 2018 were retrospectively enrolled.

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Purpose: In the endovascular era, postcoiling recanalization of cerebral aneurysms is occurring with greater frequency. Repeat coiling is usually done to prevent rebleeding, although long-term outcomes of re-embolization have yet to be adequately investigated. The present study was undertaken to assess clinical and radiographic outcomes of re-embolization in recanalized aneurysms, focusing on procedural safety, efficacy, and durability.

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Background: Cerebral aneurysms are not common among children and most of them are presented with subarachnoid hemorrhage or mass effect. Here, we describe a rare case of a pediatric giant aneurysm presented with cerebral infarction.

Case Description: A 38-month-old boy visited the emergency room due to left hemiparesis and left central type facial palsy.

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Introduction: Concerns about spontaneous intracranial hemorrhages (sICHs) have increased over time with the increasing use of antithrombotic agents. Hence, we aimed to analyze the risk and risk fractions for antithrombotics in sICHs in South Korea.

Methods: From the National Health Insurance Service-National Sample Cohort including 1,108,369 citizens, 4,385 cases, aged 20 years or more and newly diagnosed as sICHs between 2003 and 2015, were included in this study.

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Objective: Several particular morphological factors that contribute to the hemodynamics of the anterior communicating artery (ACoA) have been documented, but no study has investigated the role of the degree of anterior cerebral artery (ACA) rotation on the presence of ACoA aneurysms (ACoAAs).

Methods: A retrospective study of an institutional aneurysm database was performed; patients with ruptured or nonruptured ACoAAs were selected. Two sex- and age-matched control groups were identified: control Group A (nonaneurysms) and control Group B (middle cerebral artery aneurysms).

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Background: Reconstructive strategies for unruptured vertebral artery dissecting aneurysms (VADAs) have increasingly relied on newly developed endovascular devices. However, their clinical performance metrics are seldom reported.

Objective: To compare stent-assisted coil embolization (SACE) and flow-diverting stent (FDS) deployment as treatments for unruptured VADAs, focusing on efficacy and safety.

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Intracranial dural arteriovenous fistulas (DAVF) are abnormal connections between intracranial arterial and venous systems within the dural layers. Intracranial DAVFs are rare but can occur wherever dural components exist. The pathogenesis of DAVFs is controversial.

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Purpose: Stent protective or balloon remodeling techniques have enabled coil embolization of complexly configured aneurysms. Still, the utility of such methods may be limited in some small-caliber and/or inherently tortuous lesions. The present study was conducted to examine the efficacy of microcatheter protection (MCP) when applied in these circumstances.

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It is critical to identify the ruptured cerebral arteriovenous malformations (AVMs) for secondary prevention. However, there are rare cases unidentified on the radiological evaluation. We report on a patient with the delayed appearance of radiologically occult AVM as a probable cause of the previous intracerebral hemorrhage (ICH).

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The treatment of complicated anterior cerebral artery aneurysms remains challenging. Here, the authors describe a case of ruptured complicated A3 aneurysm, which was treated with trapping and in-situ bypass. A 47-year-old man presented to the emergency department with severe headache and vomiting.

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Objective: Intracranial vertebral artery dissecting aneurysm (VADA) may present as aneurysmal dilation alone, dilation with coexisting stenosis, or, in some cases, as a recurrent aneurysm after previous reconstructive treatment. To date, the clinical utility of flow diverters in VADA has not been examined according to these various circumstances. This study aims to report the safety and efficacy of flow diverters in the treatment of various manifestations of intracranial VADA.

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