• Journal of Chest Surgery
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• v.40 no.9
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• pp.633-636
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• 2007

Coronary artery spasm immediately after the coronary artery bypass graft (CABG) surgery is rare but it can cause sudden and severe hypotension or a ventricular arrhythmia. We report a case of low cardiac output syndrome caused by a right coronary artery spasm following CABG that did not show any significant stenotic lesions on preoperative coronary angiography.

• Journal of Chest Surgery
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• v.47 no.3
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• pp.225-232
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• 2014

Background: Redo coronary artery bypass grafting (CABG) is still associated with increased morbidity and mortality as compared to the first-time operation. Further, the application of the off-pump technique to redo CABG is limited due to technical difficulties. The aim of this retrospective study was to analyze early and midterm results after redo CABG and compare the outcome of redo on-pump and off-pump CABG. Methods: From June 1996 to October 2011, elective redo CABG was performed in 32 patients. Mean age was 64.8 years (on pump 64.3 years vs. off pump 65.5 years; p=0.658), and 21 patients were male. Among these patients, 14 (43.8%) underwent on-pump CABG, and 18 (56.2%) underwent off-pump CABG. Results: Internal thoracic artery was used in 22 patients (68.8%), and total arterial revascularization was achieved in 17 patients (53.1%). The average number of distal anastomoses was 2.13, and the rate of incomplete revascularization was 43.8%. The rate of total arterial revascularization was higher in the off-pump group (14.3% vs. 83.3%, p<0.001), and the use of saphenous vein graft was more in the on-pump group (78.6% vs. 16.7%, p<0.001). Overall hospital mortality was 3.1% (n=1) and was comparable in both groups (on pump 7.1% vs. off pump 0%; p=0.249). Postoperative complications occurred in 9 patients (64.2%), and the rate of complications was high in the on-pump group without statistical significance (64.2% vs. 33.3%, p=0.082). The mean follow-up duration was 5.4 years, and overall survival at 10 years was $86.0%{\pm}10.5%$. There was no significant difference in the 10-year survival rate between the two groups (79.6% vs. 100%, p=0.225). Conclusion: Redo CABG can be safely performed with acceptable mortality. Redo off-pump coronary artery bypass is feasible with low mortality and morbidity, comparable target vessel bypass grafting, and long-term survival. The off-pump technique might be considered a safe option for redo CABG in high-risk patients.

• Journal of Chest Surgery
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• v.33 no.8
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• pp.638-642
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• 2000

Background: In an effort t enhance long term patency of coronary bypass grafts, utilization of arterial conduits have been on an icrease. With the same objective, we have been using the right gastroepiploic artery(RGEA)in coronary artery bypass procedures since 1998. The current paper has been undertaken with the aim of assessing the apropriateness, problems, and short term results of using the RGEA as an arterial graft conduit by studying the postoperative clinical results of 100 patients than received coronary artery bypass grafting (CARG) with this artery. Material and Method: Between May of 1998 and May of 1999, an analysis of the mortality, postoperative myocardial infarction, and the need for IABP insertion as a result of low cardiac output were made between 100 consecutive patients undergoing CABG with the RGEA. Result: There was one postoperative death due to cerebral infarction. Postoperative complications/morbidity comprised myocardial infarction in 2, cerebral infarct in 3, reoperation due to bleeding in 1, mediastinitis in 1, and low cardiac output syndrome necessitating IABP in 3 patients. Complicatons related to harvesting of the arterial grafts were not experienced in any of the patients. Conclusion: The results of the current data show that utilization of the RGEA in CABG is not associated with increased mortality/morbidity and demonstrates satisfactory short term results suggesting the usefulnessof this conduit as an arterial graft.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.476-482
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• 2005

Recently, coronary artery obstructive disease and coronary artery bypass graft surgery have increased, and the operative result has been improved. We reviewed 154 cases of coronary artery bypass graft surgery from Jan. 1985 to Jun. 2004. Material and Method: We reviewed 148 patients, 154 cases of coronary artery bypass surgery from Jan. 1985 to Jun. 2004. This investigation is designed to illustrate the preoperative diagnosis, severity of disease, operative method, the kind of used bypass graft used, number of distal anasomosis, associated surgery, and postoperative morbidity and mortality. Result: There were 84 males, 64 females and the average age was $58.9\pm8.3$ years old. Preoperative clinical diagnosis were unstable angina in 97 cases $(63.0\%)$, stable angina in 31 cases $(20.1\%)$, acute myocardial infarction in 12 cases $(7.8\%)$ and postinfartion angina in 14 cases $(9.1\%)$. Preoperative angiographic diagnosis were three-vessel disease in 68 $(44.2\%)$, two-vessel disease in 39 $(25.3\%)$, one-vessel disease in 35$(22.7\%)$, and left main disease in 12$(7.8\%)$ cases. There were 78 cases of on-pump coronary artery bypass graft surgery and 76 cases of off-pump coronary artery bypass graft surgery. The total distal anastomoses number was 319, mean number of anastomoses was $2.06\pm0.96$. There were 10 concomitant procedures. Postoperative intra-aortic balloon pump was used in 21$(13.6\%)$ cases, but only 4 cases were used at off-pump coronary artery bypass surgery. Total early mortality was $7.8\%$. The mortality was decreased as $4.5\%$ from Jan. 2001 to Jun. 2004. Post operative complication was perioperative yocardial infarction in 9cases$(5.8\%)$, low cardiac output syndrome in 17 cases$(11\%)$, and arrhythmia in 30 cases$(19.5\%)$ cases. Conclusion: Since 1985, The result of coronary artery bypass graft surgery has been improved because of more refined technique, use of off-pump coronary artery bypass surgery, use of internal thoracic artery and radial artery as bypass graft. We should study the long-term follow up more for better operative results.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.259-265
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• 1982

We have designed a new type of bubble oxygenator (KOREA-KIM VENOTHERM OXYGENATOR) made of PVC sheet and deforming mesh incorporated in the heat exchanger, and evaluated in experimental animal for the analysis of it`s efficiency. The Oxygenator has low priming volume with high flow rate up to 6 L/rain, and efficiency of heat exchanger was excellent as 1-$1.5^{\circ}C.$ using total cardiopulmonary bypass method under moderate to deep hypothermia. Average priming volume of 1317 ml with 30% hemodilution method was perfused with an average of 1.1-3.0 L/min.$M^2$of arterial blood and pure oxygen at a rate of 2-3.4 L/min for 49.6 minutes continuously in average. During total cardiopulmonary bypass, average $PaO_2$ was $159.8{\pm}60$mmHg, $PaCO_2$ $41.0{\pm}3$mmHg respectively under $SaO_2$ over 96% with systolic arterial pressure of 70 mmHg and CVP of 5-10 cm$H_2O$. Plasma free Hemoglobin was $7.0{\pm}4$ mg/dl with 25% drop of hemoglobin and hematocrit at the end of cardiopulmonary bypass. This KKV Oxygenator was observed to have excellent capabillty of oxygen and carbon dioxide gas transfer with small amount of blood trauma, and the efficiency of heat exchanger was satisfactory during cooling and rewarming of the bubbled blood. Disadvantages have included the somewhat poor deforming effect due to loose PVC fiber mesh, the extracompact character of Teflon filters, and the rough inner surface of the heat exchanger copper pipes.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.528-531
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• 2009

Transesophageal echocardiography (TEE) is widely used to evaluate the heart function and the result of surgery during a cardiac operation. The incidence of complications associated with TEE is low, yet critical complications such as lower pharyngeal injury and esophageal perforation may happen. We report hereon a case of 77-year old male patient who suffered from injury to the pyriform sinus and concurrent deep neck infection after off pump coronary artery bypass surgery and intraoperative TEE.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1550-1555
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• 1992

From June 1989 to July 1992, we used centrifugal Biomedicus pump[CBP] in 20 patients In 9 cases, CBP was used as ventricular assistance after heart surgery for those who could not be weaned off bypass even with intra-aortic balloon counter-pulsation and with maximal inotropic support In 8 patients, CBP was used as partial left heart bypass during repair of aortic aneurysms or congenital aortic anomalies. And in 3 patients, CBP was used as vena caval bypass during resection of renal cell carcinoma with tumor extension into the inferior vena cava. In 2 of 9 patients with ventricular assistance, they were weaned off the device successfully after 16 hours and 7 days respectively. But the patients died of intracranial hemorrhage and sepsis, 7 and 29 days after weaning from cardiac support, respectively. In all the patients who underwent aortic of vena caval surgery using CBP as shunt, there were no complications such as postoperative bleeding necessitating reoperation, renal failure or neurologic sequelae. In conclusion, the centrifugal type of ventricular assistance may be potentially life saving treatment modality in patients with severe postoperative low cardiac output syndrome. The CBP can be safely employed for resection of renal cell carcinoma with vena caval tumor extension and for repair of aortic aneurysms.

• Journal of Korean Biological Nursing Science
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• v.9 no.1
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• pp.5-31
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• 2007

Purpose: The purpose of this study was to explore the knowledge and learning needs on cardiac rehabilitation of coronary artery bypass graft(CABG) patients. Method: The subjects consisted of 100 CABG patients at A hospital in Seoul. Data were collected by the two different kind of questionnaires which measure knowledge and learning needs on cardiac rehabilitation of CABG patients. The subjects responded the questionnaire on knowledge before CABG and that on learning needs before their discharge. Result: The mean score of knowledge on cardiac rehabilitation was 68.54. Knowledge on risk factor, nature of disease, diet, daily activity, medication, post operative care were great in order. The mean score of learning needs on cardiac rehabilitation was 4.28. Learning needs on diet, medication, nature of disease, post operative care, daily activity, risk factor were great in order. There were significant differences in knowledge according to occupation, economic status and family history(p=.021, p=.017, p=.023). There was a positive correlation between knowledge and learning needs(r=.3009, p=.002). Conclusion: Level of knowledge on cardiac rehabilitation of CABG patients is low and knowledge on postoperative care is the lowest, and learning needs are great in ail categories.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.3
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• pp.222-226
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• 2021

To comply with CE marking requirements, the electromagnetic compatibility (EMC) and low-voltage directive (LVD) tests are conducted on the sub-racks of International Thermonuclear Experimental Reactor (ITER) AC/DC converters and bypass switches. The EMC tests consist of a series of tests, including the electromagnetic interference test, the electromagnetic field immunity test, and the rapid transient burst immunity test. In the LVD test, the electric shock protection test, the xcessive temperature limit and heat resistance of equipment tests, and the fire spread prevention test are performed. This work presents and reviews the European Directive for EMC/LVD and introduces the methods of EMC and LVD tests for the sub-racks of AC/DC converters and bypass switches. It also evaluates the test method and results to meet the European Directive requirements for CE marking. The sub-racks of ITER AC/DC converters and bypass switches successfully pass the EMC and LVD tests.

• Journal of the Korean Society of Visualization
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• v.18 no.3
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• pp.103-108
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• 2020

RBC (red blood cell) deformability is one of factors inducing blood shear thinning effect. Reduction of RBC deformability increases blood viscosity in high shear region. In this study, 3D printed chip with proper distribution of wall shear rate (WSR) was proposed to measure RBC deformability of blood samples. To fabricate 3D printed chip, the design of 3D printed chip determined through numerical simulation was modified based on the resolution of the 3D printer. For the estimation of pressure drop in the 3D printed chip, two bypass outlets with low and high WSR are exposed to atmospheric pressure through the needles. By positioning the outlet of needles in the gravity direction, the formation of droplets at bypass outlets can be captured by smartphone. Through image processing and fast Fourier transform (FFT) analysis, the frequency of droplet formation was analyzed. Since the frequency of droplet formation is related with the pressure at bypass, high pressure drop caused by reduction of RBC deformability can be estimated by monitoring the formation of blood droplets using the smartphone.