• Journal of Korean Neurosurgical Society
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• v.60 no.3
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• pp.335-347
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• 2017

Intravenous recombinant tissue plasminogen activator had been the only approved treatment for acute ischemic stroke since its approval in 1995. However, the restrictive time window, numerous contraindications, and its low recanalization rate were all limitations of this modality. Under those circumstances, endovascular stroke therapy went through a great evolution during the past two decades of intravenous thrombolysis. The results of the 2013 randomized trials for endovascular stroke therapy were neutral, although they were limited by insufficient imaging screening at enrollment, early-generation devices with less efficacy, and treatment delays. Huge progress was made in 2015, as there were five randomized clinical trials which all demonstrated the safety and efficacy of endovascular stroke treatment. Despite differences in detail patient enrollment criteria, all 5 trials employed key factors for good functional recovery; (1) screening with non-invasive imaging to identify the proximal occlusion and exclude a large infarct core, (2) using highly effective modern thrombectomy devices mainly with stent retriever, and (3) establishment of a fast workflow to achieve effective reperfusion. The results of those trials indicate that modern thrombectomy devices can allow for faster and more effective reperfusion, which can lead to improved clinical outcomes compared to intravenous thrombolysis alone. These advances in mechanical thrombectomy are promising in the global fight against ischemic stroke-related disability and mortality. Two current mainstreams among such mechanical thrombectomy techniques, "stent retriever thrombectomy" and "direct clot aspiration", are the topic of this review. Stent retriever thrombectomy using Solitaire and Trevo retriever will be firstly discussed. And, the commonalities and the differences between two major clot aspiration thrombectomy techniques; a direct aspiration first pass technique (ADAPT) and forced arterial suction thrombectomy (FAST), will be additionally explained. Finally, details regarding the combination of direct clot aspiration and stent retriever thrombectomy, the switching strategy and the Solumbra technique, will be described.

• Journal of Korean Neurosurgical Society
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• v.63 no.1
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• pp.14-25
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• 2020

Proximal flow control achieved with a balloon guide catheter (BGC) during endovascular treatment of acute ischemic stroke is reviewed in this article. In clinical practice, BGCs offer a multi-faceted approach for clot retrieval by creating proximal flow arrest, reducing embolic burden, and shortening procedure time. Evaluation of frontline thrombectomy procedures with BGCs revealed advantages of combined use over the conventional guide catheter (CGC), notably in the significant reduction of distal emboli to both the affected and previously unaffected territories. Recently, new measures of early and complete reperfusion at first thrombectomy pass have been identified as independent predictors of improved outcomes, which were consistently demonstrated with use of BGC as a safe and effective option to minimize number of passes during intervention. Prior randomized controlled trials reported the positive correlation between BGC-treated patients and a lower risk of mortality as well as shortened procedure time. While BGC use is more common in stent retriever-mediated mechanical thrombectomy, preliminary data has shown the potential benefit of device application during contact aspiration thrombectomy to achieve successful recanalization. However, the question of which major endovascular strategy reigns superior as a frontline remains to be answered. Along with clinical case assessments, BGC performance during in-vitro simulation was analyzed to further understand mechanisms for optimization of thrombectomy technique.

• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.717-722
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• 2020

Objective : Dissection of the middle cerebral artery (MCA) is less common than dissection of vessels in the vertebrobasilar system or carotid artery. Acute complete occlusion related to MCA dissection is extremely rare. We report an endovascular approach in patients with acute complete occlusion due to MCA dissection. Methods : We reviewed retrospectively the endovascular procedure and clinical results for acute-stroke patients who underwent recanalization from October 2014 through December 2018. Initial imaging findings and the endovascular procedure were analyzed for patients with acute complete occlusion due to MCA dissection. Results : We undertook first-line aspiration thrombectomy using a Penumbra catheter in 294 patients with acute occlusion of the M1 segment. Of these patients, seven were confirmed to have acute complete occlusion due to MCA dissection. All patients had angiographic findings of an intimal flap at the proximal occlusion site of the MCA. One patient complained of severe headache during microcatheter passage through the occluded lesion and died due to massive bleeding caused by rupture of the false lumen. The remaining patients underwent initial contact aspiration thrombectomy without microcatheter passage. After aspiration thrombectomy, six patients had delayed flow through the MCA. One patient underwent stenting of the MCA because of progressive symptoms. Conclusion : An intimal flap at the proximal portion of an occluded MCA can suggest the possibility of MCA dissection. Contrast aspiration thrombectomy without microcatheter passage can reduce the risk of false lumen rupture in cases of MCA dissection.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.562-576
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• 2020

Acute ischemic stroke is one of the leading causes of disability and death around the world, especially in developed countries. Since the introduction of the 2nd generation devices, endovascular treatment of acute ischemic stroke has rapidly developed and is now considered to be a standard treatment. Here, we summarize the results of recent randomized clinical trials that have compared endovascular thrombectomy with conventional treatment for acute stroke and review the indications, current devices, and endovascular thrombectomy methods used.

• Korean Journal of Radiology
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• v.21 no.1
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• pp.101-107
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• 2020

Objective: Avoiding a catastrophic outcome may be a more realistic goal than achieving functional independence in the treatment of acute stroke in octogenarians. This study aimed to investigate predictors of catastrophic outcome in elderly patients after an endovascular thrombectomy with an acute anterior circulation large vessel occlusion (LVO). Materials and Methods: Data from 82 patients aged ≥ 80 years, who were treated with thrombectomy for acute anterior circulation LVO, were analyzed. The association between clinical/imaging variables and catastrophic outcomes was assessed. A catastrophic outcome was defined as a modified Rankin Scale score of 4-6 at 90 days. Results: Successful reperfusion was achieved in 61 patients (74.4%), while 47 patients (57.3%) had a catastrophic outcome. The 90-day mortality rate of the treated patients was 15.9% (13/82). The catastrophic outcome group had a significantly lower baseline diffusion-weighted imaging-Alberta stroke program early CT score (DWI-ASPECTS) (7 vs. 8, p = 0.014) and a longer procedure time (42 minutes vs. 29 minutes, p = 0.031) compared to the non-catastrophic outcome group. Successful reperfusion was significantly less frequent in the catastrophic outcome group (63.8% vs. 88.6%, p = 0.011) compared to the non-catastrophic outcome group. In a binary logistic regression analysis, DWI-ASPECTS (odds ratio [OR], 0.709; 95% confidence interval [CI], 0.524-0.960; p = 0.026) and successful reperfusion (OR, 0.242; 95% CI, 0.071-0.822; p = 0.023) were independent predictors of a catastrophic outcome. Conclusion: Baseline infarct size and reperfusion status were independently associated with a catastrophic outcome after endovascular thrombectomy in elderly patients aged ≥ 80 years with acute anterior circulation LVO.

• Journal of Korean Neurosurgical Society
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• v.67 no.4
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• pp.397-410
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• 2024

Endovascular thrombectomy (EVT) has been established as the standard of care in the treatment of acute ischemic stroke (AIS) based on landmark randomized controlled trials. Nevertheless, while the strict eligibility of EVT for AIS patients restrict the wide application of EVT, a considerable population still undergoes off-label EVT. Besides, it is important to acknowledge that recanalization is not achieved in approximately 20% of procedures, and more than 50% of patients who undergo EVT still do not experience a favorable outcome. This article reviews the brief history of EVT trials and recent progressions in the treatment of AIS, with focusing on the expanding eligibility criteria, new target for EVT, and the evolution of EVT techniques.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.3
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• pp.333-339
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• 2023

Aortic dissection is one of the causes of acute ischemic stroke. Endovascular recanalization therapy (EVT) has emerged as an essential treatment for acute ischemic stroke due to large artery occlusion. However, it is rarely performed in the situation of hidden aortic dissection (AD). Two patients presented to the emergency room with focal neurologic deficits. The first patient was diagnosed with right internal carotid artery (ICA) occlusion. Angiography revealed that the ICA was occluded by the dissection flap. After a stent deployment in the proximal ICA, the antegrade flow was restored. The patient was diagnosed with AD on chest computed tomography (CT) after EVT. For the second patient, intraarterial thrombectomy was performed to treat left middle cerebral artery occlusion. AD was first detected on echocardiography, which was performed after EVT. Herein, we report successful endovascular recanalization therapy performed in two patients with acute ischemic stroke in the situation of undiagnosed aortic dissection. We also reviewed previous case reports and relevant literature.

• Journal of Preventive Medicine and Public Health
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• v.56 no.2
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• pp.145-153
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• 2023

Objectives: Although it is difficult to define the quality of stroke care, acute ischemic stroke (AIS) patients with moderate-to-severe neurological deficits may benefit from thrombectomy-capable hospitals (TCHs) that have a stroke unit, stroke specialists, and a substantial endovascular thrombectomy (EVT) case volume. Methods: From national audit data collected between 2013 and 2016, potential EVT candidates arriving within 24 hours with a baseline National Institutes of Health Stroke Scale score ≥6 were identified. Hospitals were classified as TCHs (≥15 EVT case/y, stroke unit, and stroke specialists), primary stroke hospitals (PSHs) without EVT (PSHs-without-EVT, 0 case/y), and PSHs-with-EVT. Thirty-day and 1-year case-fatality rates (CFRs) were analyzed using random intercept multilevel logistic regression. Results: Out of 35 004 AIS patients, 7954 (22.7%) EVT candidates were included in this study. The average 30-day CFR was 16.3% in PSHs-without-EVT, 14.8% in PSHs-with-EVT, and 11.0% in TCHs. The average 1-year CFR was 37.5% in PSHs-without-EVT, 31.3% in PSHs-with-EVT, and 26.2% in TCHs. In TCHs, a significant reduction was not found in the 30-day CFR (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.76 to 1.12), but was found in the 1-year CFR (OR, 0.84; 95% CI, 0.73 to 0.96). Conclusions: The 1-year CFR was significantly reduced when EVT candidates were treated at TCHs. TCHs are not defined based solely on the number of EVTs, but also based on the presence of a stroke unit and stroke specialists. This supports the need for TCH certification in Korea and suggests that annual EVT case volume could be used to qualify TCHs.

• Journal of Korean Neurosurgical Society
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• v.59 no.4
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• pp.400-404
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• 2016

We report a case of acute ischemic stroke involving both the anterior and posterior circulation associated with a persistent primitive trigeminal artery (PPTA), treated by endovascular revascularization for acute basilar artery (BA) occlusion via the PPTA. An otherwise healthy 67-year-old man experienced sudden loss of consciousness and quadriplegia. Magnetic resonance imaging showed an extensive acute infarction in the right cerebral hemisphere, and magnetic resonance angiography showed occlusion of the right middle cerebral artery (MCA) and BA. Because the volume of infarction in the territory of the right MCA was extensive, we judged the use of intravenous tissue plasminogen activator to be contraindicated. Cerebral angiography revealed hypoplasia of both vertebral arteries and the presence of a PPTA from the right internal carotid artery. A microcatheter was introduced into the BA via the PPTA and revascularization was successfully performed using a Merci Retriever with adjuvant low-dose intraarterial urokinase. After treatment, his consciousness level and right motor weakness improved. Although persistent carotid-vertebrobasilar anastomoses such as a PPTA are relatively rare vascular anomalies, if the persistent primitive artery is present, it can be an access route for mechanical thrombectomy for acute ischemic stroke.

• Journal of Korean Neurosurgical Society
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• v.67 no.5
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• pp.578-585
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• 2024

Surgical treatment of refractory and extensive cerebral venous sinus thrombosis (CVST) has limited applications. Here, we describe an open, direct sinus thrombectomy in the early phase of extensive CVST. A 49-year-old man with extensive CVST that occurred after the coronavirus disease 2019 (COVID-19) vaccination and affected the drainage of the Labbé vein presented with clinical deterioration and left temporal hemorrhagic infarction. Since the patient had extensive CVST, we determined that systemic anticoagulation and endovascular treatment were not suitable treatment options. Therefore, we decided on an emergency surgical treatment and performed direct surgical thrombectomy. We followed extended suboccipital approach and made multiple incisions on the sinuses, exposing the posterior superior sagittal sinus to the transverse sigmoid junction. Consequently, the clinical condition of the patient dramatically improved, resulting in a favorable outcome with a modified Rankin scale score of 0. Performing emergency open surgical thrombectomy was a technically feasible treatment option that recanalize obstructed sinuses. Importantly, the patient recovered with a good clinical outcome. Early maximal surgical thrombectomy can be an effective and lifesaving method to treat extensive CVST with hemorrhagic infarction.