• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.405-413
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• 2019

Objective : We evaluated efficacy of combining proximal balloon guiding catheter (antegrade flow arrest) and distal access catheter (aspiration at the site of occlusion) in thrombectomy for anterior circulation ischemic stroke. Methods : We retrospectively analyzed 116 patients who underwent mechanical thrombectomy with stent retriever. The patients were divided by the techniques adopted, the combined technique (proximal balloon guiding catheter and large bore distal access catheter) group (n=57, 49.1%) and the conventional (guiding catheter with stent retriever) technique group (n=59, 50.9%). We evaluated baseline characteristics (epidemiologic data, clinical and imaging characteristics) and procedure details (the number of retrieval attempts, procedure time), as well as angiographic (thrombolysis in cerebral infarction (TICI) score, distal thrombus migration) and clinical outcome (National Institutes of Health Stroke Scale at discharge, modified Rankin Scale [mRS] at 3 months) of them. Results : The number of retrieval attempts was lower (p=0.002) and the first-pass successful reperfusion rate was higher (56.1% vs. 28.8%; p=0.003) in the combined technique group. And the rate of final result of TICI score 3 was higher (68.4% vs. 28.8%; p<0.01) and distal thrombus migration rate was also lower (15.8% vs. 40.7%; p=0.021) in the combined technique group. Early strong neurologic improvement (improvement of National Institutes of Health Stroke Scale ${\geq}11$ or National Institutes of Health Stroke Scale ${\leq}1$ at discharge) rate (57.9% vs. 36.2%; p=0.02) and favorable clinical outcome (mRS at 3 months ${\leq}2$) rate (59.6% vs. 33.9%; p=0.005) were also better in the combined technique group. Conclusion : The combined technique needs lesser attempts, decreases distal migration, increases TICI 3 reperfusion and achieves better clinical outcomes.

• Journal of Veterinary Clinics
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• v.33 no.6
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• pp.372-375
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• 2016

A four-year old, intact male, mixed-breed dog had a history of chronic snoring sound and dyspnea. Based on the results of computed tomography, the patient was diagnosed as nasopharyngeal stenosis. Balloon dilatation in the area of stenosis was performed using a balloon dilator inserted retrograde fashion through the working channel of an endoscope. Clinical signs were relieved but reappeared after 3 weeks. Thirty-four days following the first balloon dilatation treatment, a second procedure was performed; the balloon catheter was inserted in antegrade fashion through the left nostril and was filled with contrast agent under fluoroscopic guidance. Because of the relapse of clinical signs after 6 months, the patient received additional balloon dilatation procedure by the antegrade approach. At the one-year follow-up, the owner said that the clinical signs of nasopharyngeal stenosis had been completely resolved. Balloon dilatation could be a minimally invasive and effective treatment for nasopharyngeal stenosis, although the repetition of the procedure may be required.

• Korean Journal of Plant Resources
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• v.26 no.6
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• pp.678-685
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• 2013

The objective of this study was to examine the effect of 7 traditional Korean formulations (7TKFs) on intimal thickening of rat carotid artery injured by balloon catheter in vivo and on the proliferation of human smooth muscle cells (HASMCs) and secretion of matrix metalloproteinase-2 (MMP-2) in vitro. 7TKFs (400 mg/kg) were administered orally for 4 weeks from the day of balloon injury in the rats. HASMC proliferation was assessed by 3-(4,5-dimethylthiazol-2)-2,5-diphenyltetrazolium bromide (MTT) assay while enzymatic action of MMP-2 was carried out by gelatin zymography. Among 7TKFs, Samhwang-sasim-tang (SST), Banha-sasim-tang (BST) and Kegi-honghwa-tang (KHT) significantly reduced the intimal thickening by suppressing HASMC proliferation and MMP-2 expression in both extracellular and intracellular levels. Thus, the results suggest that SST, BST and KHT can be considered as a therapeutic value in the prevention of atherosclerosis because restenosis after PTCA (percutaneous transluminal coronary angioplasty) is supposed to be 'accelerated atherosclerosis'.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.331-334
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• 2004

In clinical use, coronary stents keep coronary arteries open after expansion with a balloon catheter and prevent the expanded artery from collapsing. Coronary stents are positioned in artery by catheter with a balloon along a guide wire to the lesion site. Flexibility is one of important ability for delivery. In this paper, Palmaz-Schatz stent and Tenax complete stent were selected because these are the most representative of tubular stents. Finite element analyses for the stent system were performed using ABAQUS/Standard code. The present study estimated the flexibility of coronary stents due to loading directions. Moreover the present paper suggests a numerical method to test the flexibility of stents. In conclusion this paper shows how the finite element analysis can be effectively organized in the stent development.

• Journal of Chest Surgery
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• v.46 no.3
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• pp.212-215
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• 2013

A 79-year-old man was admitted to Samsung Changwon Hospital due to chest pain and dyspnea. The ejection fraction was 31% and mean pressure gradient between the left ventricle and aorta was 69.4 mmHg on echocardiography. Chest computed tomography showed severe calcification of the ascending aorta. Aortic valve replacement was successfully performed using a thoracic endovascular aortic repair balloon catheter without classic aortic cross clamping. The patient was discharged on the eleventh postoperative day.

• International Journal of Vascular Biomedical Engineering
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• v.2 no.1
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• pp.25-30
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• 2004

Catheters are used to measure translesional pressure gradients in the stenosed coronary arteries. Uses of catheters during coronary angioplasty cause flow obstructions. A narrowed flow cross section with catheter effectively introduced a tighter stenosis than the enlarged residual stenoses after balloon angiplasty. Catheters in blood vessels cause pressure gradient rise and blood flow drop during the measurements. In this study, three dimensional computer simulations are conducted to investigate the flow blockage effects due to the catheter obstructions during the coronary angioplasty. The computer simulation models are generated by the data, which are measured by coronary angiogram, and the blood is treated as non-Newtonian fluid. The velocity, pressure, and wall shear stress variations are observed for the estimate of damages of blood vessel. This study is also extended to investigate the effects of stenotic vessel size, and shape and catheter size and location.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.707-708
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• 2002

Catheters are used to measure translesional pressure gradients in the stenosed coronary arteries. Catheter insertions during coronary angioplasty cause flow obstructions. A narrowed flow cross section with catheter present effectively introduced a tighter stenosis than the enlarged residual stenoses after balloon angiplasty. In general, the form of stenoses are no uniform. Sometimes, these are occurred the irregularly eccentricity If the analyses are conducted for uniform stenosed artery, the results will be underestimated. Thus, in this study, three dimensional computer simulations are conducted to investigate the flow blockage effects due to the catheter insertion during the coronary angioplasty. The results for the eccentric stenosed artery are compared with those of the concentric stenosed artery.

• 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.60 no.2
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• pp.155-164
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• 2017

Objective : To evaluate the efficacy of balloon guiding catheter (BGC) during thrombectomy in anterior circulation ischemic stroke. Methods : Sixty-two patients with acute anterior circulation ischemic stroke were treated with thrombectomy using a Solitaire stent from 2011 to 2016. Patients were divided into the BGC group (n=24, 39%) and the non-BGC group (n=38, 61%). The number of retrievals, procedure time, thrombolysis in cerebral infarction (TICI) grade, presence of distal emboli, and clinical outcomes at 3 months were evaluated. Results : Successful recanalization was more frequent in BGC than in non-BGC (83% vs. 66%, p=0.13). Distal emboli occurred less in BGC than in non-BGC (23.1% vs. 57.1%, p=0.02). Good clinical outcome was more frequent in BGC than in non-BGC (50% vs. 16%, p=0.03). The multivariate analysis showed that use of BGC was the only independent predictor of good clinical outcome (odds ratio, 5.19 : 95% confidence interval, 1.07-25.11). More patients in BGC were successfully recanalized in internal carotid artery (ICA) occlusion with small retrieval numbers (<3) than those in non-BGC (70% vs. 24%, p=0.005). In successfully recanalized ICA occlusion, distal emboli did not occur in BGC, whereas nine patients had distal emboli in non-BGC (0% vs. 75%, p=0.001) and good clinical outcome was superior in BGC than in non-BGC (55.6% vs. 8.3%, p=0.01). Conclusion : A BGC significantly reduces the number of retrievals and the occurrence of distal emboli, thereby resulting in better clinical outcomes in patients with anterior circulation ischemic stroke, particularly with ICA occlusion.

• Journal of Korean Neurosurgical Society
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• v.59 no.4
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• pp.379-384
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• 2016

Objective : Mechanical thrombectomy (MT) for acute intracranial internal carotid artery (ICA) occlusion is often complicated by difficult revascularization and non-involved territory embolization possibly related with larger clot-burden. This study aims to evaluate the efficacy of proximal aspiration thrombectomy (PAT) using a balloon-tipped guide catheter for clot-burden reduction in such cases with period-to-period analysis (period 1 : standard MT without PAT; period 2 : PAT first, then standard MT for the remaining occlusion). Methods : Eighty-six patients who underwent MT for acute intracranial ICA occlusion were included in this analysis from the prospectively maintained stroke registry (33 patients in period 1 and 53 in period 2). In period 2, 'responder' was defined as a case where some amount of clot was retrieved by PAT and the following angiography showed partial or full recanalization. Results : Fifteen of fifty-three patients in period 2 (28.3%) were 'responders' to PAT. There was a significantly higher incidence of atrial fibrillation in the 'responder' subgroup. Period 2 showed a significantly shorter puncture-to-reperfusion time (94.5 minutes vs. 56.0 minutes; p=0.002), a significantly higher Thrombolysis in Cerebral Infarction of 2b-3 reperfusion (45.5% vs. 73.6%; p=0.009), but only a trend for better 3-month favorable outcome (mRS 0-2; 36.4% vs. 54.7%; p=0.097). There was no increase in the incidence of procedure-related complications or intracranial hemorrhage in period 2. Conclusion : A strategy of PAT before standard MT may result in shorter puncture-to-reperfusion time and better angiographic outcome than a strategy of standard MT for acute intracranial ICA occlusion.