• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.136-141
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• 2021

The crossing Y-stent method is one of the indispensable techniques to achieve sufficient neck coverage during coil embolization of bifurcation aneurysms with a wide neck and/or branch incorporation. However, the inevitable hourglass-like expansion of the second stent at the crossing point can result in insufficient vessel wall apposition, reduced aneurysm neck coverage, delayed endothelialization, and subsequent higher risks of acute or delayed thrombosis. It also interferes with engagement of the microcatheter into the aneurysm after stent installation. We expected to be able to reduce these disadvantages by installing a noncrossing type Y-stent using the Solitaire AB stent, which is fully retrievable with a tapered proximal end. Here we report the techniques and two successful cases.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.359-369
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• 2019

To evaluate the effect of simultaneous use of platelet glycoprotein IIb / IIIa receptor blocker and catheter assisted thrombus aspiration in the treatment of coronary stent thrombosis. 267 patients ($64.6{\pm}12.1years$, 187 men) with stent thrombosis on coronary angiography at Chonnam National University Hospital from July 2008 to July 2017 were enrolled. We devided two groups based on treatment modalities: Group I (N=32, platelet glycoprotein IIb / IIIa receptor blocker and thrombo-aspiration), Group II (N =235, either platelet glycoprotein IIb /IIIa receptor blocker or thrombo-aspiration, or none of both), and the major cardiac events including death, revascularization and stent thrombosis were followed up for 1 year. There were no significant differences in clinical characteristics between the two groups including age (Group I: $60.8{\pm}12.9$ vs. Group II: $65.1{\pm}11.9$, p= 0.603), male (Group I: 75.0% vs. Group II: 69.4%, p=0.681), and left ventricular ejection fraction (Group I: $58.1{\pm}9.0%$ vs. Group II: $59.5{\pm}11.9%$, p= 0.127). The major cardiac events did not differ between the two groups (Group I: 12.5% vs. Group II: 23.8%, p=0.180). The secondary endopoints were as followings: The mortality rate (Group I: 0% vs. 13.2%, Group II: p=0.034), target lesion revascularization (Group I: 9.4% vs Group II: 6.4%, p=0.461) and stent thrombosis (Group I: 3.1% vs. Group II: 4.7%, p=1.000). In conclusion, in the treatment of coronary artery stent thrombosis, simultaneous use of platelet glycoprotein IIb / IIIa receptor blocker and thrombus aspiration was associated with better clinical outcomes regarding 1 year mortality.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.273-283
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• 2012

Drug-eluting stents (DES) have significantly reduced in-stent restenosis, compared to bare-metal stents (BMS). However, there remains concern for the increased risk of stent thrombosis (ST) associated with DES. The present study sought to evaluate the incidence, clinical characteristics and outcome of ST in patients with acute myocardial infarction (MI) during a 1-year follow-up. 80 patients who developed ST were divided into 2 groups according to stent type: group I (DES-ST, n = 57 ) and group II (BMS-ST, n = 23 ). There were no differences between group I and II in the overall incidence of ST (2.7% vs. 4.3%, p=0.064) and in the incidence of each type of ST: acute ST (8.8% vs. 2.3%), subacute ST (50.9% vs. 60.9%), late ST (19.3% vs. 8.7%), and very late ST (21.1% vs. 17.4%) (p=0.605). Predictors of 1-year mortality were the occurrence of ST (OR 8.12, 95% CI 2.83-23.61, p<0.001), left ventricular ejection fraction<40% (OR 6.41, 95% CI 2.42-16.96, p<0.001), and age${\geq}$75 years (OR 4.98, 95% CI 1.95-12.74, p=0.001).

• Journal of Medicine and Life Science
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• v.20 no.3
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• pp.131-134
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• 2023

Here, we present a case of a 56-year-old man with acute myocardial infarction. The patient underwent percutaneous coronary intervention (PCI) at the left main bifurcation and mid-left anterior descending artery using drugeluting stents. Four months after the PCI, the patient was readmitted for cardiac arrest. Coronary angiography (CAG) revealed stent thrombosis in the left main-to-proximal left anterior descending artery and in-stent restenosis in the left main-to-proximal left circumflex artery. We performed balloon angioplasty at the left main to mid-left anterior descending artery and left main to proximal left circumflex artery stents; subsequently, blood flow was fully restored. However, contrast agent extravasation was observed outside the mid-portion of the left main artery to the proximal left anterior descending artery stent, indicating the presence of a coronary artery aneurysm (CAA) outside the stent. After guideline-directed medical therapy with dual antiplatelet agents and high-intensity statins, follow-up CAG revealed near-resolution of the CAA, absence of stenotic lesions, and good blood flow.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.757-762
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• 2009

Background: Compression of the left common iliac vein by the overriding common iliac artery is frequently combined with acute deep vein thrombosis in patients with May-Thurner Syndrome. We evaluate the results of treatment with thrombolysis and thrombectomy followed by stenting in 34 patients with May-Thurner Syndrome combined with lower extremity deep venous thrombosis. Material and Method: The authors retrospectively reviewed the records of 34 patients (mean age: $65{\pm}14$ year old) who had undergone stent insertion for acute deep vein thrombosis that was caused by May-Thurner syndrome. After thrombectomy and thrombolysis, insertion of a wall stent and balloon angioplasty were performed to relieve the compression of the left common iliac vein. Urokinase at a rate of 80,000 to 120,000 U/hour was infused into the thrombosed vein via a multi-side hole thrombolysis catheter. A retrieval inferior vena cava (IVC) filter was placed to protect against pulmonary embolism in 30 patients (88%). Oral anticoagulation with warfarin was maintained for 3 months, and follow-up Multi Detector Computerized Tomography (MDCT) angiography was done at the date of the patients' hospital discharge and at the 6 months follow-up. Result: The symptoms of deep venous thrombosis disappeared in two patients (4%), and there was clinical improvement within 48 hours in twenty eight patients (82%), but there was no improvement in four patients (8%). The MDCT angiography at discharge showed no thrombus in 9 patients (26%) and partial thrombus in 21 (62%), whereas the follow-up MDCT at $6.4{\pm}5.5$ months (32 patients) revealed no thrombus in 23 patients (72%), and partial thrombus in 9 patients (26%). Two patients (6%) had recurrence of DVT, so they underwent retreatment. Conclusion: Stent insertion with catheter-directed thrombolysis and thrombectomy is an effective treatment for May-Thurner syndrome combined with acute deep vein thrombosis in the lower extremity.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.202-205
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• 2003

Deep vein thrombosis (DVT) is a common disease. However, May-Thurner syndrome, which is the cause of DVT, is an uncommon processes in which there is an impaired venous return due to compression of the left iliac vein by the overlying right common artery. This condition results in a left iliofemoral deep thrombosis and severe leg edema. It is, therefore, called iliac compression syndrome. Catheter-directed thrombolytic therapy of acute extensive iliofemoral DVT and balloon angioplasty with venous stenting are recommended. Two cases with history of left leg swelling are diagnosed as May-Thurner syndrome, which was demonstrated by venography. We successfully treated the patients with thrombolysis, balloon angioplasty, and stent insertion at the site of common iliac vein compression. Therefore, we report the cases with overall review of the literature.

• Journal of Korean Neurosurgical Society
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• v.53 no.5
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• pp.274-280
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• 2013

Objective : To evaluate the feasibility and clinical and angiographic outcomes of stent-assisted embolization for complex middle cerebral artery (MCA) aneurysms. Methods : The records of 23 consecutive patients with 24 MCA aneurysms, who underwent stent-assisted embolization of the aneurysm, were retrospectively evaluated. Results : Fifteen aneurysms were treated with one stent and 8 were treated using more than two stents (5 a stent-within-a-stent, 1 triple stents, and two Y-stent). Angiographically, complete or near complete occlusion was achieved in 15 aneurysms (65.2%), residual neck in five (21.7%), and residual aneurysm in three (13.1%). Five aneurysms demonstrated thrombosis within the stent during the procedure and hospitalization, and were resolved by intraarterial and intravenous Tirofiban injection. Symptomatic thromboembolic complications were developed in five patients and permanent deficits demonstrated in two patients with modified Rankin Scale 1 and 2, respectively. Treatment-related permanent morbidity and mortality rates were 8.3% and 0% with relatively high complication rate. Angiographic follow-up was available in 17 aneurysms at 6-31 months (mean, 13.2 months) and showed stable or improved in 15 (88.2%) and major and minor recurrence in one, respectively. Conclusion : Complex MCA aneurysms could be treated by stent-assisted coiling and showed lower recanalization rate during mid-term follow-up by effective flow diversion due to various stent-assisted techniques. Our results warrant further study with a longer follow-up period in a larger sample.

• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.853-863
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• 2021

Objective : Biodegradable poly-L-lactic acid (PLLA) with a highly biocompatible surface via tantalum (Ta) ion implantation can be an innovative solution for the problems associated with current biodegradable stents. The purpose of this study is to develop a Taimplanted PLLA stent for clinical use and to investigate its biological performance capabilities. Methods : A series of in vitro and in vivo tests were used to assess the biological performance of bare and Ta-implanted PLLA stents. The re-endothelialization ability and thrombogenicity were examined through in vitro endothelial cell and platelet adhesion tests. An in vivo swine model was used to evaluate the effects of Ta ion implantation on subacute restenosis and thrombosis. Angiographic and histologic evaluations were conducted at one, two and three months post-treatment. Results : The Ta-implanted PLLA stent was successfully fabricated, exhibiting a smooth surface morphology and modified layer integration. After Ta ion implantation, the surface properties were more favorable for rapid endothelialization and for less platelet attachment compared to the bare PLLA stent. In an in vivo animal test, follow-up angiography showed no evidence of in-stent stenosis in either group. In a microscopic histologic examination, luminal thrombus formation was significantly suppressed in the Ta-implanted PLLA stent group according to the 2-month follow-up assessment (21.2% vs. 63.9%, p=0.005). Cells positive for CD 68, a marker for the monocyte lineage, were less frequently identified around the Ta-implanted PLLA stent in the 1-month follow-up assessments. Conclusion : The use of a Ta-implanted PLLA stent appears to promote re-endothelialization and anti-thrombogenicity.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.523-530
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• 2022

Objective : To evaluate the safety and efficacy of an overlapped stenting-assisted coiling technique in treating vertebral artery dissecting aneurysm (VADA) via Low-profile Visualized Intraluminal Support (LVIS) stent-within-Neuroform EZ stent. Methods : From January 2017 to June 2019, 18 consecutive patients with VADAs (ruptured : unruptured=5 : 13) were treated with the overlapping stents assisted-coiling technique in our center. The overlapping manner was a Neuroform EZ stent being deployed first, followed by LVIS stents placement using the 'shelf' technique. The patients' clinical characteristics, technical feasibility and safety, and immediate and follow-up angiographic results were retrospectively reviewed. Results : Seventeen (94.4%) procedures were technically successful with an exact deployment of the stents and patent parent or perforator arteries. The immediate angiographies after procedure confirmed Raymond class I, II, and III occlusion of VADAs were in 12 (66.7%), two (11.1%), and four cases (22.2%), respectively. Post-procedural complications developed in one patient (5.6%) with minor brainstem infarctions, which resulted from an in-stent thrombosis during the procedure. Angiographic follow-up at 5.7 months (range 3 to 9 months) demonstrated Raymond class I and II occlusion were in all cases (100%). The modified Rankin Scale scores at 21.3 months (range 15 to 42 months) 0-2 in 17 cases (94.4%) and three in one case (5.6%). Conclusion : Overlapping stents via LVIS stent-within-Neuroform EZ stent combined with coiling is safe and effective for patients with VADA in the midterm results.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.497-502
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• 2018

The coronary artery disease (CAD) is rapidly increasing such as angina pectoris and atherosclerosis. The CAD is induce by cholesterol and calcium like plaque absortion to artery wall. The percutaneouss coronary intervention is non-invasive treatment that narrowed-artery is expand by using balloon catheter and bare metallic stent. The metallic stents have been effective in reducing the dead by coronary artery disease, but the permanent presence of the metallic stent has been associated with persistent inflammation, and incidence of late thrombosis. Therefore, development bioresorbable vascular scaffold (BRS) is rapidly increasing for treatment of long-term complications and arterial restenosis by permanentmetal prosthesis such as stent. The review discusses the BRS trend for successfully development.