• Proceedings of the KSME Conference
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• 2001.11b
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• pp.585-590
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• 2001

The hemodynamic characteristics were compared using commercial CFD code for the stenosed coronary and abdominal arteries. Numerical calculations were carried out in the axisymmetric arteries over the stenotic diameter ratios ranging from 0.25 to 0.875 (6 cases) employing the typical physiological flow conditions. In case of the coronary artery, there was only one recirculation zone observed distal to the stenosis throat during the major portion of the period. However, in case of the abdominal aorta, there were complex recirculation regions found proximal and distal to stenosis throat. For both models, the wall shear stresses(WSS) increased sharply in the converging stenosis, reaching a peak just upstream of the throat, and became negative or low values in the post-stenotic recirculation region. As the results, the oscillatory shear index(OSI) was abruptly increased at the stenosis throat. For the coronary stenosis model, the second peak in the OSI was observed distal to the stenosis. The distance between the first peak and the second peak was increased as the degree of the stenosis was raised. On the orther hand, the abdominal stenosis model showed a complex oscillatory behavior in the OSI index and did not showed such a strong second peak. As the degree of stenosis was increased, recirculation regions of the both arteries were extended much longer and flow pattern became more complex.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.661-666
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• 1989

Congenital coronary arterial fistulae are the most prevalent hemodynamically significant congenital coronary artery malformations. Definition of congenital coronary arterial fistula is a direct communication between a coronary artery and the lumen of one of the four cardiac chambers or coronary sinus or SVC, pulmonary artery or pulmonary vein close to the heart. It is often associated with additional congenital or acquired heart disease. A 49 year old male patient was admitted with the chief complaints of anginal pain and exertional dyspnea for 9 months. He was diagnosed as the right coronary arterial fistula combined with right coronary arteriosclerotic stenosis and old inferior myocardial infarction by cardiac evaluation. The right coronary arterial fistula was communicated between the just distal portion of acute marginal branch and coronary sinus. The operative procedure was as followings; after suture ligation of fistula opening in the coronary sinus under beating heart, coronary arterial bypass grafting with saphenous vein was performed at the just proximal portion of the posterior descending branch under cardiopulmonary bypass. The postoperative course was uneventful and he was discharged without anginal pain at the 8th postoperative day.

• Journal of Chest Surgery
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• v.32 no.10
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• pp.943-946
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• 1999

There was no significant difference in morbidity and mortality between those that received simultaneous operation for coronary artery disease and peripheral vascular disease versus those that received coronary artery bypass graft alone. Simultaneous operation is also cost effective. A 46 year-old patient with resting chest pain and intermittent claudication was diagnosed as unstable angina and Leriche's syndrome. We performed simultaneous revascularization for coronary artery stenosis with internal mammary artery and right gastroepiploic artery and a bifurcated vascular graft interposition between in the aorta, left common iliac and right femoral arteries for Leriche's syndrome. The postoperative coronary angiogram and aortogram revealed a good patency of the arterial conduits and vascular graft. He has been followed for 12 months without any problem.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.111-115
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• 1997

The objective of present study is to obtain information about stenosis effects on the blood flow in the coronary artery bifurcation. The three dimensional steady of blood in the coronary artery bifurcation with stenosis and without stenosis are simulated using the finite volume method. Apparent viscosity of blood is represented as a function of shear rate by the Carreau models. Velocities vectors and wall shear stresses along the branch tubes with stenosis are compared with those of without stenosis for steady flows. Flow phenomena in the stenosed branch tubes are discussed extensively.

• Journal of Chest Surgery
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• v.35 no.1
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• pp.20-26
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• 2002

Background: Due to the concern of flow competition or retrograde steal, it has been generally suggested that the right gastroepiploic artery(RGEA) pedicled graft should be used in critical coronary stenosis lesion. The study was designed to evaluate the potential of retrograde flow competition in the RGEA pedicled graft by measuring the native pressure differences(PD) between the normal coronary artery and celiac arterial pressure, which would be compared with trans-stenosis pressure gradients(TSPG) in coronary artery occlusive disease. Material and Method: Between July, 1998 and February, 1999, pressures of the right coronary artery and the right gastroepiploic artery(or the celiac artery) were measured in patients with the patent right coronary artery(n=12). The PD between the arteries was compared with the TSPG in the occlusive coronary arteries(n=32). Result: The pressures of the normal right coronary artery and celiac artery were 143$\pm$23 vs. 134$\pm$17mmHg in systole(p<0.005), 74$\pm$13 vs. 73$\pm$14mmHg in diastole(p=NS), and 100$\pm$16 vs. 97$\pm$15mmHg in mean (p<0.05). The PD between the arteries were -8~25mmHg in systole, -4~7mmHg in diastole, and -1~10mmHg in mean. The TSPG measured in the occlusive coronary arteries were -4~19(7$\pm$5.8)mmHg in the lesion less than 75% stenosis vs. 7~74(27$\pm$18.3)mmHg in the 75% or over stenosis lesion(p<0.005). The normally existing pressure difference between the coronary arteries and RGEA(15~20mmHg) was significantlyless than the TSPG in .the occlusive coronary artery with 75% or over stenosis(p<0.001). Conclusion: If the pressure gradient between the RGEA and the coronary artery distal to the stenosis is the main determinant of development of retrograde flow competiton in the RGEA pedicled graft, the above data suggests that there will be little chance of competition when It is used in the coronary lesion with 75% or over stenosis.

• Journal of Chest Surgery
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• v.49 no.4
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• pp.225-231
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• 2016

Throughout its 30-year history, the right gastroepiploic artery (GEA) has been useful for in situ grafts in coronary artery bypass grafting (CABG). The early graft patency rate is high, and the late patency rate has improved by using the skeletonized GEA graft and proper target selection, which involves having a target coronary artery with a tight >90% stenosis. Total arterial revascularization with the internal thoracic artery and GEA grafts is an option for achieving better outcomes from CABG procedures.

• Journal of Chest Surgery
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• v.45 no.4
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• pp.251-253
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• 2012

We report a redo coronary artery bypass grafting (CABG) in a 55-year-old man. Angina recurred 7 years after the initial surgery. Coronary angiography showed all patent grafts except a faint visualization of the in situ right gastroepiploic artery (RGEA) graft, which was anastomosed to the posterior descending coronary artery, associated with celiac axis stenosis. Redo-CABG was performed at postoperative 10 years because of aggravated angina and decreased perfusion of the inferior wall in the myocardial single photon emission computed tomography. The saphenous vein graft was interposed between the 2 in situ grafts used previously; the right internal thoracic artery and RGEA grafts. Angina was relieved and myocardial perfusion was improved.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.688-691
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• 2002

Takayasu's arteritis is a chronic inflammatory disease of unknown cause. It predominantly affects the aortic arch and its branches. Concomitant involvement of coronary and renal arteries is a rare entity. In this report, we described successful treatment of a patient with Takayasu's arteritis associated with coronary and renal arteries stenosis. A 23-year-old woman was presented with chest pain on exertion. Angiographic studies demonstrated left main coronary, bilateral renal, and left subclavian arteries stenosis. She underwent angioplasty and stenting of bilateral renal artery. After one week, coronary artery bypass grafting using greater saphenous veins and aorto-subclavian bypass with PTFE vascular graft were done simultaneously. She was discharged on the 13th postoperative day without any complications.

• Journal of Chest Surgery
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• v.26 no.11
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• pp.833-837
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• 1993

In an effort to reduce the stroke rate of patients after coronary artery bypass, many authors have studied the prevalence of the extracranial carotid disease and its role in determining neurologic morbidity and mortality rates. From April 1992 to August 1993, Seventy-five patients undergoing coronary artery bypass were preoperatively evaluated for presence of carotid and femoral stenosis by Duplex sono. Among them, fourteen patients was positive by Duplex sono and overall prevalence of carotid or femoral stenosis was 18.7%. And significant carotid stenosis [ > 60% ] had proved to be in 3 patients [ 4.0% ].Prophylatic bilateral carotid endarterectomy was performed in one patient, at 5 months prior to and , 1 week prior to coronary artery bypass respectively. Their mean age was 57.6 years [ ranged from 40 to 70 years] and were composed of 10 males and 4 females. There was no postoperative morbidiry and mortality related to neurologic complications. Our data, although small, suggest that preoperative carotid screening is helpful to determine patients at high risk of stroke, and significant simultaneous carotid and coronary atherosclerosis should be corrected in selected patients by staged operations when feasible.

• 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.