• Journal of Chest Surgery
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• v.36 no.8
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• pp.630-632
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• 2003

In off-pump coronary artery bypass grafting (CABG), multiple proximal anastomosis may increase the risk of cerebral embolism (air, debris) and aortic injury (dissection, pseudoaneurysm). Radial artery (RA) has no intraluminal valve such as saphenous vein. We applied Cabrol technique using aortic root replacement for proximal anastomosis in off-pump CABG. Cabrol technique using RA graft can reduce numbers of proximal anastomosis and reduce number of aortic manipulation in off-pump CABG. We report a Cabrol technique for proximal anastomosis in off-pump CABG with RA graft.

• 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.

• Journal of Chest Surgery
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• v.38 no.5 s.250
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• pp.349-356
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• 2005

Background: Arterial conduits using in coronary artery bypass grafting (CABG) have been known a great long term patency rates, and improved short and long term clinical outcomes. It has been reported that Off pump CABG has better clinical results than CABG using cardiopulmonary bypass. To evaluate the advantage of arterial conduits over venous conduits and to avoid the adverse effects of cardiopulmonary bypass, we performed total arterial Off pump CABG. Material and Method: From January 2001 to October 2004, Off pump CABG using only arterial conduits was performed on 325 patients with a mean age of $59.3\pm11.9$ years ($36\~83$). Mean ejection fraction was $55.4\pm14.0\%\;(15\~86).$ Angiography showed left main disease or triple-vessel disease in $81.9\%$ of the patients. Indications of using arterial conduits was stenosis $\ge50\%$ of left anterior descending artery, stenosis $\ge80\%$ of branches of left circumflex artery, and stenosis $\ge90\%$ of right coronary artery and its branches. Multi-slice computed tomography was performed on 194 patients to evaluate the short term patency rates. Result: A total of 928 distal anastomoses were performed and the average anastomoses per a patient were $2.86\pm0.78$. There was 1 operative mortality. Postoperative complications were mediastinitis in 6 patients ($1.8\%$), renal failure in 4 patients ($1.2\%$), perioperative myocardial infarction in 3 patients ($0.9\%$), reoperation for bleeding in 3 patients ($0.9\%$). There was no postoperative stroke. Patency rate of arterial conduits was $99.3\%$ (581/585). There were 4 stenoses or competitive flows in 2 radial arteries and 2 right internal mammary arteries. Conclusion: Total arterial Off pump CABG appears to be safe, showing a low surgical mortality and morbidity and excellent short term patency rates of arterial conduits.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.659-665
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• 2003

The aim of this study was to evaluate the early and midterm results of off-pump total arterial revascularization using the skeletonized right gastroepiploic artery (RGEA) as a third arterial conduit. Material and Method: We prospectively analyzed 103 patients who underwent off-pump total arterial revascularization using bilateral internal thoracic arteries (ITAS) and RGEA. The RGEA was used as in situ graft in 88 patients, composite graft in 10 patients, and free graft in 5 patients. Postoperative coronary angiographies were performed before discharge in 100 patients, and at postoperative one year in 88 patients. Result: The RGEA showed a significantly higher free flow (130$\pm$95 ml/min) than that of right ITA(113$\pm$57 ml/min) or left ITA (107$\pm$55 ml/min), which was measured before anastomosis (p < 0.05). The total number of distal anastomoses was 3.8$\pm$0.7. The number of distal anastomoses per bilateral ITAs was 2.8$\pm$0.7 and the number of distal anastomosis per RGEA was 1.0. There were two morialities including one operative mortality. The late mortality was not related to cardiac events. Early postoperative morbidities were atrial fibrillation in 15 patients, bleeding reoperation in 4 patients, mediastinitis in 1 patients, perioperative myocardial infarction in 2 patient, and transient ARF in 3 patients. Postoperative coronary angiographies showed the early patency rate of 98.6％ (272/276) for ITAs and 97.0％ (97/100) for RGEA, respectively (p=ns), and the one-year patency rate of 95.9％ (234/244) for ITAs and 88.6％ (78/88) for RGEA, respectively (p=0.07). Flow competition between the RGEA and NCA (native coronary artery) was seen in 5 of the 100 patients (5.0％) immediate postoperatively and 7 of the 88 patients (8.0％) 1 year after surgery. Since July, 2000, we measured transit time flow intraoperatively and could reduce flow competition significantly Conclusion: The skeletonized RGEA demonstrated excellent early and midterm patency rates and could be used as a third arterial graft following the bilateral ITAs.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.884-892
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• 1998

Background: The gastroepiploic artery is not only an alternative graft but also may be considered an important primary graft for coronary revascularization. However, the long-term patency of the gastroepiploic arterial graft is yet to be determined and the incidence of perioperative spasm and long-term patency of a coronary graft may be affected by the properties of the graft response to certain vasoactive substances. The reactivity of the gastroepiploic artery to vasoactive substances has not been studied extensively and the results of the studies are contradictory. Material and Method: This study was designed to test the reactivity of human gastroepiploic artery to four constrictors and four relaxants. The middle sections of the human gastroepiploic arteries were collected from the patients undergoing gastrectomy and the arterial rings with intact endothelium were suspended in organ baths for isometric tension recording. Result: Epinephrine, norepinephrine, and potassium chloride induced the maximum constriction to higher forces (7.0$\pm$1.1g, 6.6$\pm$0.9g, and 6.5$\pm$1.1g) than 5-hydroxytryptamine did (3.8$\pm$1.7g, p<0.05). Nitroprusside and histamine induced almost full relaxation in the gastroepiploic arteries preconstricted with norepinephrine. There was no significant difference between two relaxants regarding maximum relaxation force. Acetylcholine induced the maximum relaxation to weaker force when compared with nitroprusside and histamine (p<0.05), and isoproterenol was the weakest of the relaxants (p<0.05 compared with acetylcholine). Conclusion: The gastroepiploic artery has a strong capacity of endothelium-dependent relaxation which could have an important influence on long-term patency. The gastroepiploic artery exhibits a potent contractility to catecholamines and the enhanced contractility may facilitate vasospasm in the presence of high circulating levels of catecholamines. Nitroprusside, a potent relaxant in gastroepiploic artery, might be beneficial for the treatment of gastroepiploic arterial graft spasm. The gastroepiploic arterial graft with intact endothelium may respond weakly to beta-adrenoceptor agonist and 5-hydroxytryptamine.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.35-42
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• 2004

Background: For the treatment of isolated left main coronary artery disease, twelve arterial revascularizations with Y-composite grafts using left internal thoracic artery and radial artery or right gastroepiploic artery were peformed. This study was performed to investigate whether V-composite graft can satisfy the blood flow required to make myocardium act properly or not. Borderline stenotic lesions on the left main coronary artery, which are very prone to remodel the bypassed vessels due to competitive flows, were also considered. Material and Method: Among 247 patients who underwent coronary artery bypass grafting from March 2000 to April 2003, 12 patients (4.7%) who had received total arterial revascularizations for the isolated left main coronary artery disease were studied retrospectively. Result: left anterior descending arteries were bypassed with left internal thoracic artery by off-pump technique in all patients, however, 2 cases of left obtuse marginal branches were bypassed under on-pump beating heart. Except for one patient, who did not have an obtuse marginal branch more than 1 mm in diameter, 11 patients had gone through complete arterial revascularizations by use of the Y shape arterial graft. Among five patients who had less than 75% stenosis, one patient showed string sign on left internal thoracic artery grafted to left anterior descending artery. However, two grafts to obtuse marginal blanches were completely obstructed and one showed slender sign. There were no graft-dominant flow in patients with stenotic lesion less than 75%. On the contrary to the result of patients with stenotic lesions less than 75%, all the patients with stenotic lesions more than 90% showed graft-dominant blood flow. Conclusion: In conclusion, it is assumed that, when stenotic lesions are over 90%, coronary artery bypass grafting with an Y shape arterial graft could possibly give enough help to the obstructed coronary arteries in blood supplying to myocardium, which needs massive quantity of blood to act well. However, when patients have borderline stenoses, through scrupulous examinations, more prudent and flexible decisions are required in choosing the treatment methods, such as, direct anastomosis of vein or artery to aorta, or adding supplementary treatment methods like percutaneous coronary intervention, rather than choosing a fixed treatment methods.

• 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.38 no.11 s.256
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• pp.761-772
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• 2005

Background: Following the implantation of heart valve prostheses, it is important to maintain therapeutic INR to reduce the risk of thromboembolism. The objective of this study was to suggest a practical dosing guideline for Korean outpatients with prosthetic heart valves managed by a pharmacist-run anticoagulation service (ACS). Material and Method: A retrospective chart review was completed for all patients enrolled in the ACS at Seoul National University Hospital from March, 1997 to September, 2000. Patients who were at least 6 months post-valve replacement and had nontherapeutic INR value (less than 2.0 or greater than 3.0) were included. The data on 688 patients (1,782 visits) requiring dosing adjustment without any known drug or food interaction with warfarin were analyzed. The amount of adjusted dose and INR changes based on the INR at the time of the event were calculated. Aortic valve replacements (AVR) patients and mitral or double valve replacement (MVR/DVR) patients were evaluated separately. Result: Two methods for the warfarin dosage adjustment were suggested: Guideline I (mg-based total weekly dose (TWD) adjustment), Guideline II (percentage-based TWD adjustment). The effectiveness of Guideline 1 was superior to Guideline II overall in patients with both AVR and MVR/DVR. Conclusion: The guideline suggested in this study could be useful when the dosage adjustment of wafarin is necessary in outpatients with mechanical heart valves.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.535-545
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• 2005

Environmental survey from some abandoned metal mine areas was undertaken on to assess the risk of adverse health effects on human exposure to arsenic influenced by past Au-Ag mining activities. Elevated levels of As were found in tailings from the studied mine areas. This high concentration may have a impact on soils and waters around the tailing piles. In order to perform the human risk assessment, chemical analysis data of soils, rice grains and waters fur As have been used. The HQ values fer As via the rice grain and groundwater consumption were significantly higher compared with other exposure pathways in all metal mine areas. However, there were minimal soil and water dermal contact risks. The resulting Hl values of As from the Dongil, Okdong and Hwacheon mine areas were higher than 5.0, and their toxic risk due to drinking water and rice grain was strong in these mine areas. The cancer risk of being exposed to As by the rice grain route from the Dongil, Okdong and Hwacheon mine areas was $5.2\times10^{-4},\;6.0\times10^{-4}\;and\;8.1\times10^{-4}$, respectively. The As cancer risk via the exposure pathway of drinking water from these mine areas exceeded the acceptable risk of 1 in 10,000 fer regulatory purposes. Thus, the daily intakes of groundwater and rice grain by the local residents from the Dongil, Okdong and Hwacheon mine areas can pose a potential health threat if exposed by long-term arsenic exposure.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.149-159
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• 2008

Background: With increasing coronary bypass and peripheral vascular surgeries, the demand for homologous vascular or synthetic conduits has continued to grow, but wide-spread application has been limited by dismal patency rates. Although cryopreserved allograft valves may provide a suitable alternative, current viability or patency of implanted allograft vascular conduits has been unsatisfactory. Material and Method: We serially analyzed the outcomes of canine femoral artery and saphenous vein allograft implants after storage in either $4^{\circ}C\;or\;-170^{\circ}C$. Result: There were no differences in graft flow rate (patency) (p=0.264), rate of thrombosis (p=0.264), presence of endothelium (p=0.587), or immunohistochemical staining for thrombomodulin (p=0.657) were detected between grafts stored in $4^{\circ}C\;and\;-170^{\circ}C$. Greater flow occurred in the arterial grafts versus the venous grafts (p=0.030), irrespective of the preservation method, with a significantly lower incidence of thrombosis (p=0.030) in arterial allografts. There was a correlation coefficient of -0.654 between thrombosis and positive immunohistochemical staining for thrombomodulin (p=0.006) and a correlation coefficient of 0.520 (p=0.0049) between the endothelial presence and positive immunohistochemical staining for thrombomodulin. The relationship between the presence of endothelium and thrombomodulin expression failed to show any correlation within the first 2 weeks (p=0.306). However, a strong correlation was seen after 1 month (p=0.0008). Conclusion: Tissue storage in either $4^{\circ}C\;or\;-170^{\circ}C$ in 10% DMSO/RPMI-1640 preservation solution preserved grafts equally well. In terms of thrombosis and graft patency, arterial grafts were superior to venous grafts. Considering the poor correlation between thrombomodulin expression and the presence of an endothelium in the implanted graft within the first two weeks, grafts in this period would not be thromboresistant.