• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.153-159
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• 2012

Bypass anastomosis is frequently adopted for surgical treatments of stenosed coronary arteries. Optimal coronary bypass grafting should be investigated to improve the patency in arterial bypass techniques. The objective of this study is to analyze the effects of Y-grafting bypasses and T-grafting bypasses for various bifurcation and anastomotic angles. In order to find the optimal geometric configuration, the hemodynamic characteristics are obtained and compared with each other for different geometries. We found that both the left anterior descending artery (LAD) and left circumflex artery (LCX) blood flows were distributed evenly when the bypass grafting angle and bifurcated angle were $30^{\circ}$ and $15^{\circ}$, respectively,.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.230-239
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• 1994

In Order to evaluate determinants of successful percutaneous transluminal coronary angioplasty (PTCA), PTCA was performed for 172 coronary arterial lesions in 120 patients (89 male, 31 female) at Yeungnam university hospital from Sep. 1992 to Aug. 1993. The corinary artery luminal diameter at the site of the original stenosis was eveluated from end-diastolic frames of identical projections of the preangioplasty and immediate post angioplasty. The coronary luminal and balloon diameters were measured with using of computer measuring system. Overall success rate of 172 attempted lesions was 87.2%. Success rate of female patients was 93.5% and higher than those of male patients. According to the clinical diagnosis, success rate in stable angina was 93.7% and higher than those of post myocardial infarction angina, unstable angina and acute myocardial infarcrion. Success rate of American Heart Association type C lesion was 65.5% and lower those of type A (95.7%), type B (89.5%). There was signfifcantly difference in preangioplasty luminal stenosis, elastic recoil and length of lesion between successful PTCA group and failed PTCA group. Success rate of lesion location at a bend > $45^{\circ}$ and presence of intracoronary thrombus were lower than than those of other angiographic findings. In coclusion, primary angioplasty success was affected by specific angiographic factors. Stenosis severity, thrombus, lesion location at a bend > $45^{\circ}$, elastic recoil, and length of lesion were the principle of determinants of coronary angioplasty success rate.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.326-329
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• 1997

Coronary artery bypass grafting(CABG) without cardiopulmonary bypass(CPB) is now an accepted technique of myocardial revascularization in selective cases of coronary arterial occlusive disease. The lesion was total(100%) occlusion of proximal right coronary artery(RCA) without any evidence of dis,Base in the rest of coronary arteries. Percutaneous transluminal angioplasty(PTCA) was tried but unsuccessful. We herein report a case of successful CABG to right coronary artery without CPB on a patient with complete occlusion of RCA and symptomatic wit minimal activity.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1190-1196
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• 1997

Between July 1994 and August 1995, 78 patients underwent coronary artery bypass graft at Seoul National University Hospital. Coronary angiogram was performed one year after coronary artery bypass graft in 49 patients(62.8%) for evaluation of the graft patency and analysis of the risk factors for graft occlusion. The patency rates of both the internal mammary artery and the radial artery grafts were 100% , although three internal mammary artery grafts(5.0%) were narrowed(string sign). And that of the saphenous vein grafts were 85.2%. Multivariate analysis for the preoperative, operative, and postoperative factors was done between the widely patent and the narrowed internal mammary artery graft groups, and between the patent and the occluded saphenous vein graft groups by the general linear models procedure. Patient's age($\geq$60 years), postoperative intraaortic balloon pump insertion, bleeding, and acute renal failure were found to be the significant risk factors for internal mammary artery graft narrowing, and coronary artery size(< 1.5 mm) was the significant risk factor for the saphenous vein graft occlusion (p<0.05) . This study confirms that the arterial graft is superior to the vein graft at one-year patency rate, and suggests the risk factors for graft occlusion during the first postoperative year. Knowledge of this study may provide a basis for estimating the risk factors for graft occlusion, and thereby modifying surgical strategy and postoperative surveillance.

• Proceedings of the KTCVS Conference
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• 1998.10a
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• pp.70-70
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• 1998

• Journal of Yeungnam Medical Science
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• v.16 no.1
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• pp.101-107
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• 1999

We evaluated the results of sequential SPECT dual-isotope imaging with Tl-201 and Tc-99m MIBI in 24 patients. all of whom also had coronary angiography within the past one month. Coronary angiography showed that 12 patients had no CAD, 4 patients had one-vessel CAD, 7 patients had two-vessel CAD and 1 patient had three-vessel CAD. Serial studies of resting Tl-201 and dipyridamole stress Tc-99m MIBI were completed within 2 hours. When more than 50% of coronary artery narrowing was considered significant, the overall sensitivity and specificity of CAD detection were 91.7%. The sensitivity of CAD detection in patients with one-vessel and multi-vessel diseases was 75% and 100%. respectively. Therefore, sequential dual-isotope SPECT demonstrated high sensitivity and specificity for CAD detection. In conclusion, sequential dual-isotope imaging is feasible and can be completed in a short time and may therefore enhance laboratory throughput and patient convenience.

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.207-207
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• 2003

• Journal of Chest Surgery
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• v.40 no.11
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• pp.773-776
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• 2007

A 47-year-old male with hypertension, diabetes mellitus and heavy smoking, but no anginal symptoms, presented with claudication of the lower extremities. Extremity angiography with coronary angiography revealed peripheral arterial lesions including a left subclavian artery occlusion with coronary artery disease. The patient underwent an initial off-pump coronary artery bypass with an ascending aorto-axillary bypass. The right internal mammary artery was anastomosed to the left anterior descending coronary artery. The greater saphenous vein graft was connected from the ascending aorto-axillary bypass graft to the diagonal branch. At postoperative day 18, femorofemoral and bilateral femoropopliteal bypasses were performed. We report a case of the combined repair of coronary artery disease and a left subclavian artery occlusion.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.225-232
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• 2004

Purpose : Transient wall motion abnormality and contractile dysfunction of the left ventricle (LV) can be observed in patients with coronary artery disease due to post-stress myocardial stunning. To understand clinical characteristics of stress induced LV dysfunction, we have compared the findings of exercise stress test, myocardial perfusion SPECT and coronary angiography between subjects with and without post-stress LV dysfunction. Materials and Methods : Among subjects who underwent exercise stress test, myocardial perfusion SPECT and coronary angiography within a month of interval, we enrolled 36 patients with post-stress LV election fraction (LVEF) was $\geq5%$ lower than rest (stunning group) and 16 patients with difference of post-stress and rest LVEF was lesser than 1 %(non-stunning group) for this study. Treadmill exercise stress gated myocardial perfusion SPECT was performed with dual head SPECT camera using 740 MBq Tc-99m MIBI and coronary angiography was also performed by conventional Judkins method. Results : Stunning group had a significantly higher incidence of hypercholesterolemia than non-stunning group(45.5 vs. 7.1%, p=0.01). Stunning group also had higher incidence of diabetes mellitus and lower incidence of hypertension, but these were not statistically significant. Stunning group had larger and more severe perfusion defect in stress perfusion myocardial SPECT than non-stunning group(extent 18.2 vs. 9.2%, p=0.029; severity 13.5 vs. 6.9, p=0.040). Stunning group also had higher degree of reversibility of perfusion defect, higher incidence of positive exercise stress test and higher incidence of having severe stenosis ($80{\sim}99%$) in coronary angiography than non-stunning group, but these were not statistically significant. In stunning group, all of 4 patients without perfusion defect had significant coronary artery stenosis and had received revascularization treatment. Conclusion : Patients with post-stress LV dysfunction had larger and more severe perfusion defect and severe coronary artery stenosis than patients without post-stress LV dysfunction. All of the patients without perfusion defect in stunning group had significant coronary artery stenosis and needed revascularization. Therefore, we suggest that invasive diagnostic procedures and therapeutic interventions might be needed in patients with post-stress LV dysfunction.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.570-577
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• 2004

CT angiography is now available to evaluate the early graft patency after coronary bypass surgery. We investigated whether patency or occlusion of the bypass grafts can be visualized by CT angiography and what factors effect the visuality. Material and Method: Fifty patients underwent scanning with a 4-slice computed tomographic scanner (Somatom Volume ZoomTM; Siemens, Germany) before being discharged after coronary artery bypass grafting. To evaluate graft patency and relationship between the quality of graft image and the characteristics of the diseased coronary vessels, 50 internal thoracic artery grafts, 18 radial artery grafts, and 56 vein grafts were included in this study. Result: All vein grafts (24 grafts; 32 anastomoses) to left coronary artery system were well visualized, but 3 grafts (4.7%) of 30 vein grafts (35 anastomoses) to right coronary artery system were not visualized. The latter was also occluded in invasive coronary angiographic study. Thirty-nine (78%) internal thoracic artery grafts were well visualized, 8 (16%) faintly visualized, and 3 (6%) not visualized, but all the internal artery grafts were well patent in invasive coronary angiographic study. Conclusion: Unvisualized vein grafts in CT angiography means occlusion of the grafts, but unvisualized arterial grafts in CT angiography may not mean occlusion of the graft but result from competitive flow between the graft and coronary artery. To confirm patency of the unvisualized arterial grafts, invasive coronary angiography is needed.