• International Journal of Vascular Biomedical Engineering
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• 제1권2호
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• pp.20-29
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• 2003

A new treatment for coronary artery occlusive disease is being developed in which a shunt or conduit is placed directly connecting the left ventricle with the diseased artery at a point distal to the obstruction. To aid in assessing and optimizing its benefit, a computational model of the cardiovascular system was developed and used to explore various design conditions. Simulation results indicate that in complete LAD occlusion, flow can be returned to approximately 65% of normal if the conduit resistance is equal for forward and reverse flow, increasing to 80% in the limit in which backflow resistance is infinite. Increases in flow rate produced by asymmetric flow resistance are considerably enhanced in the case of a partial LAD obstruction since the primary effect of resistance asymmetry is to prevent leakage back into the ventricle("steal") during diastole. Increased arterial compliance has little effect on net flow with a symmetric shunt, but leads to considerable augmentation when the resistance is asymmetric. These results suggest that an LV-LAD conduit will be beneficial when stenosis resistance(Rst) > 27 PRU if resistance is symmetric.

• Journal of Chest Surgery
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• 제28권9호
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• pp.876-880
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• 1995

The optimal surgical approach to the patients with coronary artery disease combined with carotid artery stenosis is controversial. We report two cases of successful surgical management of the patients with combined obstructive coronary and carotid artery disease. The first case was a 69-year-old female who had unstable angina pectoris and a past medical history of left carotid endarterectomy. She was revealed to have triple vessel coronary disease and nearly total occlusion of right internal carotid artery. She was undergone staged right carotid endarterectomy 10 days before coronary bypass surgery. The second case, a 54-year-old male with a past medical history of left hemiparesis and dysarthria, was admitted due to unstable angina pectoris. He was revealed to have triple-vessel coronary disease and more than 90% stenosis of left internal carotid artery and 50% stenosis of right internal carotid artery. In the latter case, a combined coronary bypass surgery and left carotid endarterectomy was done. In both cases, postoperative neurologic complications were not observed.

• Journal of Chest Surgery
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• 제50권2호
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• pp.105-109
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• 2017

Coronary arterial involvement in Takayasu arteritis (TA) is not uncommon. Herein, we describe a case of TA with celiac trunk and superior mesenteric artery occlusion combined with coronary artery disease. Bilateral huge internal thoracic arteries (ITAs) and the inferior mesenteric artery provided the major visceral collateral circulation. After percutaneous intervention to the right coronary artery, off-pump coronary artery bypass grafting for the left coronary territory was done using a right ITA graft and its large side branch because of its relatively minor contribution to the visceral collateral circulation.

• Journal of Chest Surgery
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• 제23권3호
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• pp.514-521
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• 1990

Patient with aortic valvular disease have increased left ventricular work and greater myocardial oxygen demand, which may aggravate the effect of concomitant coronary artery disease. Thus in patient who repair aortic valve replacement, concomitant aortocoronary bypass surgery is often performed when angiographically significant coronary artery disease is present. This approach is supported by reports that revascularization does not increase operative risk when associated coronary artery disease is present and significantly reduce the occurrence of late sudden death. Recently we have experienced one case of aortic valve replacement concomitant with aorta-coronary bypass surgery. The patient was 56 year-old male and admitted with complaint of anterior chest pain especially during his exercise. He was diagnosed as aortic valve stenosis and regurgitation [GIII] with proximal right main coronary artery occlusion We performed aortic valve replacement with aorta coronary bypass surgery by use of saphenous vein. Post operative course was uneventful and chest pain was relieved. Post operative coronary angiogram disclosed good patency of grafted vessel.

• Korean Journal of Radiology
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• 제20권6호
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• pp.1001-1002
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• 2019

• Journal of Chest Surgery
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• 제56권5호
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• pp.359-361
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• 2023

Coronary ostium obstruction due to dislodgement of the prosthetic valve is a rare and life-threatening complication, and particular caution is required for sutureless aortic valve replacement (AVR) with concomitant valvular surgery. In general, coronary artery bypass surgery is performed when coronary ostium obstruction occurs after AVR, but other options may need to be considered in some cases. Herein, we present a case of coronary artery occlusion in an 82-year-old female patient who had undergone AVR and mitral valve replacement for aortic valve stenosis and mitral valve stenosis at the age of 77 years. A hybrid procedure involving redo AVR and percutaneous coronary intervention after left main coronary ostium endarterectomy was performed. To summarize, we present a case of hybrid AVR in a patient with coronary artery obstruction after AVR that was successfully managed using this method.

• Applied Microscopy
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• 제23권1호
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• pp.139-163
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• 1993

Background: It has been well established and is now no longer a controversial issue that ischemia produces a series of inflammatory reactions and the ischemic myocardium cannot survive without adequate restoration of coronary flow, ie, reperfusion. Nevertheless, controversies that intravascular pluggings (IVP) by polymorphonuclear leukocytes (PMNs) or platelets may cause contractile dysfunction in ischemia and even in repefusion still remain. Accordingly, we attempted to examine the intravascular plug fomation as well as the ultrastructural changes in myocytes and microvessels and to determine the relation among them. Methods: 1) Human (n= 10, 39-63 years of age; 3 females and 7 males): left ventricular myocardium (LVM) was biopsied from chronic ischemic heart disease patient during bypass surgery. 2) Calf (Holstein-Friesian species, n=4): Circumflex branch of the left coronary artery (LCx) was occluded (ischemia) for 45 minutes and recanalized (reperfusion) for 3 and 6 hours, respectively and LVMs were biopsied after occlusion and recanalization, respectiverly. 3) Rat (Sprague-Dawley species, n=20): Left coronary artery (LCA) was occluded for 20 minutes and recanalized for an hour as the method described by Selye et al., (1960) and hearts were removed after occlusion and recanalization, respectively. 4) Pig (landrace type, n=7): Anterior ascending branch of the left coronary artery (LAD) was coccluded for 45 minutes and recanalized for 2 hours and LVMs were biopsied after occlusion and recanalization, repectively. All of the LVMs were routinely prepared for transmissiom electron microscopy. Rseults: In human, most of the LVM showed irreversible ultrastructural changes in myocytes and frequent IVPs by PMNs or platelets without any significant correlation with age or sex. In the animal LVM, myocytes showed reversible ultrastructural changes with slight variations in accordance with the species, duration of ischemia and reperfusion or site of biopsy, however, injuries were more severe in the subendocardial myocytes and IVPs by PMNs or platelets were frequently observed. Ultrastructural changes in the myocytes seemed to be gradually improved by recanalization, howerver, IVPs were still observed after recanalization. Conclusion: These results suggest that microvessels are more resistant to ischemic insult than the myocytes themselves and IVP by PMNs and platelets may play an important role to produce ischemic or reperfusion injuries. Thus, it is favorable that angioplasty is preceded by thrombolysis and it is likely that restoration of myocardial function requires relarively long period of time even after recanalization.

• Advances in biomechanics and applications
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• 제1권4호
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• pp.279-292
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• 2014

This paper presents some simulations of fluxes and pressures in the coronary network, in the case of very severe coronary disease (several stenoses on the left branches and total occlusion of the right coronary artery). In that case, coronary artery bypass graft surgery is the commonly performed procedure. However, the success of the intervention depends on many factors. Modeling of the coronary circulation is thus important since it can help to understand the influence of all these factors on the coronary haemodynamics. We previously developed an analog electrical model that includes the eventual presence of collateral flows, and can describe the different revascularization strategies (two grafts, three grafts, ...). The aim of the present work is to introduce in our simulations the time-dependence of the coronary microvascular resistances, in order to better represent the effect of the systolic ventricular contraction (which induces an elevation of the resistances because the vessels are squeezed).

• Journal of Yeungnam Medical Science
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• 제35권2호
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• pp.227-231
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• 2018

Left main coronary artery (LMCA) thrombosis is rare and the cause should be determined. A previously healthy young man presented with severe chest pain and dyspnea. The electrocardiogram showed typical ST-segment elevation myocardial infarction with clinical instability. Emergency coronary angiography revealed complete LMCA occlusion by thrombosis. After reperfusion, the patient was admitted to the cardiac care unit. He was diagnosed with hemolytic anemia and tested positive for antinuclear antibodies. Systemic lupus erythematosus (SLE) and LMCA disease due to systemic thrombosis were diagnosed. Steroids were started and the patient was discharged without complications. We report this rare case of LMCA thrombosis as an initial presentation of SLE.

• Journal of Trauma and Injury
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• 제33권3호
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• pp.186-190
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• 2020

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been increasingly used in recent years as a resuscitative adjunct for trauma patients with life-threatening non-compressible torso hemorrhage. By blocking the aorta temporarily with an inflated balloon, REBOA preserves cerebral and coronary perfusion while diminishing exsanguination below the balloon, thereby providing time for resuscitation and definitive bleeding control. When determining the occlusion zone during the REBOA procedure, factors such tortuosity of the aorta, co-occurring minor chest injuries, and the severity of shock must be considered, as well as the main injury site. This paper describes a case of high Zone I REBOA in an elderly patient with a tortuous aorta who had concomitant injuries of the chest and pelvis.