• Journal of Pharmaceutical Investigation
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• v.38 no.2
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• pp.93-98
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• 2008

The drug-eluting stent (DES) implantation is a widely acceptable treatment for coronary heart disease. It was reported that iron chelator had anti-proliferative effect on human vascular smooth muscle cells (HA-VSMCs). In this study, tetraphenylporphine (TPP) was selected as an iron chelator and drug for DES. MTT assay showed that TPP had antiproliferative effect on HA-VSMCs. TPP and polycaprolactone (PCL) were coated onto stainless steel plate using a spraycoating method. From the surface morphology examination of the coated plate by SEM, smooth polymer coating layer could be observed. The thickness of coating layer could be controlled by changing repeating time of coating. From in vitro release test, sustained release of TPP was observed from plate during two weeks. Thus, TPP as iron chelator can be used as drug for stent coating because of its antiproliferative effect and sustain release profile.

• Journal of Chest Surgery
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• v.38 no.6 s.251
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• pp.434-437
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• 2005

Since the operative mortality rate of the Acute aortic dissection has been reducing, a more extensive primary repair of the dissected aorta is preferred for acute aortic dissection to reduce the needs of secondary procedures. We performed a total aortic arch replacement with distal stent-grafting in acute type A aortic dissection. The patient was a 50-years old man. He recovered from the operation and was followed up for 7 months. The pseudolumen in the descending aorta was obliterated with the stent.

• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.5-10
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• 2012

There is a still unsettled issue about the comparison of long-term clinical effects between sirolimus-(SES) and paclitaxel-eluting stents (PES) for the patients with acute myocardial infarction (AMI). Therefore, we performed a retrospective analysis to evaluate the 4-year clinical outcome of SES as compared with PES after percutaneous coronary intervention (PCI) in patients with AMI. From January 2004 to August 2006, all consecutive patients with acute ST-segment elevation myocardial infarction (STEMI) underwent primary PCI and acute NSTEMI underwent PCI by implantation either SES or PES were enrolled. The occurrence of death, cardiac death, recurrent infarction, target vessel revascularization (TVR) and stent thrombosis were analyzed. The composite of major adverse cardiac events (MACE; death, recurrent infarction and TVR) were also analyzed. During the study period, total 668 AMI patients had visited. Of them, total 522 patients (299 with SES and 223 with PES) were enrolled. During 4-year clinical follow-up, there were similar occurrences of death ($18.3{\pm}3.0%$ vs. $14.6{\pm}2.2%$, p=0.26), cardiac death ($11.2{\pm}2.6%$ vs. $6.8{\pm}1.52%$, p=0.39), re-infarction ($6.4{\pm}1.8%$ vs. $3.3{\pm}1.1%$, p=0.31), and stent thrombosis ($5.4{\pm}1.7%$ vs. $3.2{\pm}1.1%$, p=0.53) between the two groups, consecutively. The occurrences of TVR ($10.0{\pm}3.0%$ vs. $4.0{\pm}1.2%$, p=0.008) and MACE ($29.4{\pm}3.5%$ vs. $19.4{\pm}2.5%$, p=0.003) were significantly higher in patients treated with PES than SES. In AMI patients treated with either SES or PES implantation, SES had a significantly lower risk of TVR and MACE during 4-year clinical follow-up. Rates of death, cardiac death or recurrent infarction, and stent thrombosis were similar.

• 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 Chest Surgery
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• v.39 no.10 s.267
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• pp.754-758
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• 2006

Background: Surgical role for acute coronary syndrome has been reduced in recent years due to development of drug eluting stent. We evaluated the surgical results of acute coronary syndrome in our hospital. Material and Method: Between January 2001 and August 2005, 416 patients underwent coronary artery bypass grafting (CABG) under diagnosis of non-ST-elevation acute coronary syndrome (NSTE ACS). Mean age was $61.8{\pm}9.0$ years and 276 (66.3%) patients were male. 324 (77.9%) patients had triple vessel disease and 92 (22.1%) had left main disease at angiographic study. 236 (56.7%) patients had hypertension and 174 (41.8%) had diabetes mellitus. Conventional on-pump CABG was performed in 194 patients (46.6%) and off-pump CABG in 222 (53.4%). Total arterial revascularization with no touch technique was done in 97 patients (23.3%). The number of total distal anastomosis was 1,306 and the number per patient was $3.21{\pm}1.71$. Result: Surgical mortality rate was 1.0% (4 patients) and postoperative complication rate was 15.6% (65 patients). Graft patency was checked at mean $3.7{\pm}7.6$ months (from 1 to 37 months) postoperatively with multi-directional computed tomography in 152 patients. Left internal mammary artery was patent in 95.3%, right internal mammary artery in 98.1%, radial artery in 92.2% and saphenous vein in 89.0%. Conclusion: The surgical treatment of NSTE ACS showed relatively low mortality rate and good graft patency rate. Further study is needed to compare the long term results with drug eluting stent.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1915-1918
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• 2003

Atherosclerosis, which is a degenerate disease, is believed to occur in the vascular system due to deposition of cholesterol and low density lipoprotein(LDL) or thrombosis on the blood vessel. Atherosclerosis narrows arterial lumen, which is known as stenosis phenomenon of blood vessel. Pathogenesis of atherosclerosis is thought to occur mainly by aging. Restenosis phenomenon is observed in the same site of insertion of a stent and balloon angioplasty after treatment of interventional theraphy. Several hypothetical theories related to the generation of atherosclerosis have been reported: high shear stress theory, low shear stress theory, high shear stress gradient theory, flow separation and turbulence theory and high pressure theory. However, no one theory clearly explains the causes of atherosclerosis. In the present study the generation of atherosclerosis in the left coronary artery is investigated. The hypotheses are verified by using the computer simulation.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1637-1640
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• 2004

관상동맥 폐색증 환자들에 대해서 시술되는 stent 삽입 시술이나 관상동맥 우회로 시술 중에는 X-ray 등의 조영 영상이 시술의 기준이 되고 있다. 따라서 조영 영상에서 혈관을 빠르게 인식하는 것은 정확하고 효과적인 시술의 필수 조건이다. 이러한 시술 중 빠르고 정확한 혈관 인식을 위하여 본 논문에서는 심혈관 조영 영상으로부터 관상동맥의 형태를 자동적으로 영상분할하기 위한 방법을 제안한다. 우선 조영 영상에서 혈관을 분명하게 인식하기 위해서는 잡음을 제거하기 위한 필터링이 필요한 데, Anisotropic diffusion을 이용한 필터링은 이미지 내 물체의 경계선을 보존하고, 영역 내의 잡음을 제거하는 데 효과적이다. 정확한 영상분할을 수행하기 위해서는 대부분의 경우 사용자가 영상 내에 관심 영역을 지정하는 인터렉션이 필요하지만 이는 사용자에게 불편함을 줄 수 있다. 따라서 이러한 번거로움을 최소화하고, 정확한 결과를 유도하기 위해서 자동 씨드 영역 추출 알고리즘을 제안한다. 따라서 조영 영상에 필터링을 적용한 후 추출된 씨드 영역과 추출된 에지와 Adaptive region-growing을 복합적으로 사용하는 영상분할을 수행하게 되면 보다 효과적인 관상동맥 영상 분할의 결과를 얻을 수 있었다.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.319-336
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• 2020

The purpose of this study was to compare the outcomes of two interventional methods, overlapping drug-eluting stents (DES) and long DES, for long-term clinical outcomes in patients with acute myocardial infarction (AMI). A total of 438 patients with AMI (65.9±11.0 years, 306 males) from June 2008 to March 2019 who had diffuse long coronary artery lesion, more than 30mm were divided into two groups; group I (overlapped DES group; n=140) and group II (long DES group; n=298). We compared the incidences of major adverse cardiac events [MACEs; cardiac death, myocardial infaction (MI), target lesion revascularization (TLR) and stent thrombosis (ST)] during 12 months between the two groups. Everolimus-eluting stent was more commonly used in group II than in group I (28.1% vs. 51.8% p<0.001). Mean lesion diameter was slightly longer in group II (3.1±0.3mm vs. 3.2±0.3mm, p=0.042), and prevalence of ACC/AHA lesion type C was higher in group I (41.7% vs. 25.4%, p<0.001). Incidences of MACEs during 12 months were higher in group I than group II (18.5% vs. 14.4%, p=0.034). The rates of cardiac death (2.1% vs. 4.4%, p=0.667), MI (5.0% vs. 2.7%, p=0.260) and stent thrombosis rate (0.7% vs. 1.7%, p=0.669) were similar between the two groups. However, TLR rate was higher in group I (10.7% vs. 5.6%, p=0.041). In multivariate logistic regression analysis, presence of diabetes mellitus [Hazard ratio (HR) 2.383, 95% confidence interval (CI) 1.332-4.260, p=0.003] and use of paclitaxel-eluting stent (HR) 2.367, 95% CI 1.371-4.086, p=0.002) were independent predictors of 12-month MACEs, without significant differences in prevalence between the two groups. In AMI patients with diffuse long lesion, TLR rate was higher in the overlapped DES group during 12-month follow-up. Presence of diabetes and use of paclitaxel-eluting stent were independent predictors of MACEs.

• Polymer(Korea)
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• v.34 no.2
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• pp.178-183
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• 2010

Medical metal stents inserted to patients with a cardiovascular disease associated with coronary artery system have relatively increased the survival rate. The development of new stents is, however, urgently required due to restenosis and late thrombosis generated in metal stents. To solve these problems, the biodegradable polymers such as poly(lactide-co-glycolide) (PLGA), poly(L-lactide)(PLLA), and poly ($\varepsilon$-caprolactone)(PCL) were mixed with alpha lipoic acid (ALA), which is well known to inhibit the proliferation of neointimal hyperplasia. Subsequently, the ALA-loaded polymers were coated on stainless steel by electrospray. The drug-eluting behaviors from the coated polymers were investigated according to kinds and concentrations of polymers, spray rates, and kinds of solvents. The drug-eluting rate from PCL with the lowest glass transition temperature was the fastest among three polymers and followed by PLGA and PLLA. The surface roughness increased as the spray rate was increased and also the drug-eluting rate was affected by kinds of solvents with different boiling point. It is expected that drug-eluting stent (DES) coated with ALA-loaded polymers can be applied practically for clinical applications by controlling the behavior of drug release.

• Journal of Chest Surgery
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• v.38 no.11 s.256
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• pp.733-738
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• 2005

Background: The possibility of incomplete revascularization and development of flow competition after revascularization of the borderline lesion made the hybrid strategy as an option for complete revascularization. Material and Method: From January f998 to July 2004, 25 $(3.2\%)$ patients underwent hybrid revascularization among 782 total OPCAB procedures. Clinical results and angiographic patencies were evalulated. Percutaneous coronary intervention (PCI) was peformed before CABG in 8 patients and after CABG in 47 patients. Result: The causes of PCIs before CABG were to achieve complete revascularization with minimally invasive surgery (n=7) and emergent PCI for culprit lesion (n=1). The indications of PCIs after CABG were high possibility of flow competition in the borderline lesion of right coronary artery territory (n=8), diffuse atheromatous lesion preventing anastomosis of graft (n=5), severe calcified ascending aorta with no more arterial grafi available (n=3), and intramyocardial coronary lesion (n=1). Mean number of distal anastomoses was $2.3\pm1.0$. Mean number of lesions treated by PCI was $1.2\pm0.4$. There was no operative or procedure-related mortality. PCI-related complication was periprocedural myocardial infarction in one patient, and complications related to CABG were transient atrial fibrillation (n=5), perioperative myocardial infarction (n=1), and transient renal dysfunction (n=1). Early postoperative coronary angiography $(1.8{pm}1.6days)$ revealed $100\%$ patency rate of grafts (57/57). The stenosis occurred in one patient performed PCI before CABG, which was successfully treated with re-ballooning. During midterm follow-up (mean; $25{\pm}26$ months), 1 patient died of congestive heart failure. All survivors (n=24) accomplished follow-up coronary angiographics, which showed .all grafts (56/57) were patent except one string sign. In-stent restenosis was developed in 2 patients who received bare metal stents. Conclusion: In selected patients, complete revascularization was achieved with low risk by taking the hybrid strategy.