• 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.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.36 no.5
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• pp.309-315
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• 2003

Background: To avoid the adverse effects of cardiopulmonary bypass and to overcome late vein graft failure we routinely peformed off-pump total arterial coronary revascularization. Material and Method: From July 2000 to August 2001, 104 consecutive patients underwent first elective off-pump total arterial coronary revascularization. Both internal mammary, radial and gastroepiploic arteries were used. Sequential and composite grafts were used to achieve complete revascularization. Perioperative adverse events and postoperative angiograms were analyzed. Result: A total of 252 arterial conduits were used with an average of 2.47 grafts per patient. A total of 326 distal anastomosis were performed with a mean of 3.13 distal anastomosis per patient. Cross over to on-pump occurred in seven patients (6.7%). Of these 4 were due to unstable hemodynamics during lateral or posterior wall stabilization as a result of cardiomegaly and 3 were due to uncontrolled bleeding during dissection of diffusely dimunitive deeply placed intramyocardial coronary arteries. There were no opeartive deaths. Two cases of perioperative myocardial infarction and transient neurologic complications occurred, respectively. Of the 312 distal anastomoses, 308 (98.7%) were compatible with Fitz-Gibboll A or B patency grading. Conclusion: Off-pump total arterial coronary revascularization was technically feasible in most elective cases with satisfactory early results. However, on-pump coronary bypass surgery should be considered in difficult circumstances, such as cardiomegaly or unfavorable anatomy of the target coronary artery.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.458-472
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• 1987

A heart supplies bloods of about 15, 000 liters to each human organ in a day. A normal function of heart valves is necessary to this act of heart. The disease of heart valve develops to a narrowness of a closure, resulting in an abnormal circulation of bloods. In an attempt to eliminate the affliction of heart valves, the operation method to repair with artificial heart valves has been developed and saved numerous patients over past 30 years. This replacement operation has been performed since early 1960`s in Korea, but all the artificial heart valves used are imported from abroad with very high costs until recent years. The artificial heart valve using pyrolytic carbon has been developed at KAIST, which was proved to be stable in the mechanical performance and durability. Therefore, the in viva performance of this valve was examined through animal tests. The artificial heart valves used in this study are tilting disc type valves, in which the disc were made of graphite coated with pyrolytic carbon and the cages were made of titanium. In viva testings of these valves were performed in 12 dogs, in which right ventriculo-pulmonary arterial [Croup I] or inter-aortic [Croup IV] valved conduit was implanted using polytetrafluoroethylene conduits containing KAIST valve and aortic valve [Group II] or pulmonary valve [Croup III] was replaced by a KAIST valve with a 21mm or 19mm tissue annulus diameter. In group I and II, pre-and post-operative transvalvular pressure gradient was measured and compared with other prosthetic valves. During post operative period laboratory examination was performed including hemoglobin, hematocrit, red cell count, white cell, lactic acid dehydrogenase and platelet. The eight surviving dogs were sacrificed and autopsy was performed at 2, 6, and 8 weeks. KAIST valve has low transvalvular gradient and relatively high orifice area. Average ventriculo-aortic peak systolic transvalvular gradient was 14 mmHg in 21 mm valve and 19 mmHg in 19 mm valve. The valve has slight intravascular hemolysis effect. Thrombogenic effect of low polishing quality and eddy currents around small orifice is high. The valve has vulnerability of disc movement. These animal tests suggest that the improvement of the heart valve design, surface polishing state and prescription methods.

• Journal of Chest Surgery
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• v.39 no.4 s.261
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• pp.298-303
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• 2006

Background: This study was performed to investigate the outcomes of vascular operations that were done in patients with atheroscerosis obliterans (ASO) of lower limb. Material and Method: Forty patients underwent vascular operations from December 1996 to June 2004. The patient's records were analyzed retrospectively. Mean age was $66{\pm}8$ years (range, $47{\sim}81$ years). Gender ratio was 37:3 (male:female). Result: The operations were done on 50 lower limbs of 40 patients. The names of operations were femoropopliteal bypass in 12 patients (30%), femorofemoral bypass in 12 (30%), femorofemoral bypass and femoropopliteal bypass in five (12.5%), aorta-lower limb artery bypass in five (12.5%), axillofemoral bypass in two (5%), iliopopliteal bypass in two (5%), and endarterectomy in two (5%). All bypass surgeries were done with prosthetic conduits. Mean follow up period was $33.2{\pm}23.2$ months (range, $3.8{\sim}90.2$ months). The cumulative patency rates of 1 and 5 years were 75.5 and 58.7% respectively. In six patients, amputation of the lower limb was done. In eight patients, 12 complications occurred. After the first operation, 10 patients underwent reoperations. Conclusion: Our lower limb arterial bypass surgery revealed acceptable patency rate, but not a few patients required reoperations. An epochal treatment modality that can inhibit the progress of ASO and improve long term patency should be established.

• Journal of Chest Surgery
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• v.40 no.8
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• pp.546-551
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• 2007

Background: The radial artery is gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there have been limited reports about its angiographic patency compared with that of internal thoracic artery or saphenous vein. We tried to evaluate angiographic patency of radial artery graft and to compare that of radial artery and other gratis with retrospective manner. Material and Method: From January 2001 to Jure 2006, totally 132 patients (male 92, female 40) who underwent coronary artery bypass graft using radial artery were re-admitted to our hospital for follow up angiographic examination. Mean age was 58.2+8.87 and mean follow up duration was 32 month ($2{\sim}110$ month). Off pump and on pump bypass surgery were performed 74 and 58 patients respectively. Along with radial artery, left internal thoracic arteries were used in 57 cases, concomitant left internal thoracic artery and saphenous veins were used in 47 cases and bilateral internal thoracic arteries were used in 20 cases. Result: Totally 412 distal anastomosis were performed and 376 anastomosis remained patent (91.2%). Left internal thoracic artery showed the most excellent patency in all of the conduits (98.5%). Radial artery graft patency was 90.8% (169/186). There was no statistical difference of the patency by conduit between on-pump and off-pump group. But radial artery showed more higher patency rate (98/110, 89%) in the severe stenotic lesion that preoperatively revealed more than 90% stenosis than in the lesser severe (<90%) stenotic lesion (60/76, 78%)(p < 0.005). Radial artery conduit represented the worst result when it was grafted in the right coronary system. But when it was positioned in the left heart especially diagonal or obtuse marginal area, patency was comparable with left internal thoracic artery. Conclusion: Radial artery graft showed good midterm patency when it was used in the severe stenotic lesion more than 90% and left coronary system. But great notice should be taken when it is grafted in the right coronary system or less severe stenotic lesion.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.583-590
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• 2001

The aim of this study was to compare one-year graft patency after coronary artery bypass grafting without cardiopulmonary bypass(OPCAB) with that of conventional CABG and that of on-pump beating CABG, and to demonstrate any differences in patency of various conduits among the three groups. Material and Method: We analyzed the results of OPCAB cases(group I; n=122) compared with those of conventional CABG cases(group II; n=65) and those of on-pump beating CABG cases(group III; n=19). In group I, coronary angiography(CAG) was performed immediately postoperatively and 1 year after surgery. In group II and III, CAG was performed 1 year after surgery. Graft patency was graded as grade A(excellent), grade B(fair), or grade O(occluded). Result: The average number of distal anastomoses in groups I, II, and II were 3.1$\pm$1.1, 3.7$\pm$0.9, and 3.6$\pm$0.9, respectively. In group I, postoperative CAG was performed in 92%(112/122) of patients before discharge. The patency rate(grade A+B) was 96.4$(162/168) for arterial grafts, and 85.6%(160/187) for saphenous vein grafts(SVG). One-year follow-up CAG was performed in 74%(90/122) of patients. The patency rate was 97.8%(132/135) for arterial grafts, and 67.9%(106/156) for SVG. In group II, one-year follow-up CAG was performed in 65%(42/65) of patients. The patency rate(grade A+B) was 93.5%(43/46) for arterial grafts, and 86.8%(33/38) for SVG. Conclusion: Our results demonstrated that the patency rate of SVG after OPCAB was significantly lower than that of arterial grafts in the early postoperative CAG(p<0.001), and was also significantly lower than those of SVG of group II(p<0.001) and group III(p<0.01) in the postoperative one-year CAG, although there was no significant difference is one-year patency of arterial grafts among the three groups. Our data suggest that a specific perioperative anticoagulant therapy may be advisable in patients undergoing OPCAB with SVG.

• Journal of Chest Surgery
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• v.38 no.9 s.254
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• pp.601-608
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• 2005

Background: To maximize the histological advantage and minimize the physiological disadvantage, we have been using the skeletonized gastroepiploic artey (GEA) as a free graft for total arterial revascularization. The aims of the current study was to assess the efficacy of the skeletonized GEA as a composite or extended graft for total arterial revascularization. Material and Method: Between January 2000 and Feburary 2005, 133 patients (43 female, mean age=61.8 yrs) undergoing coronary artery bypass grafting (CABG) with a skeletonized GEA as free graft (22 extended, 107 composite and 4 others) were enrolled in this study. Coronary angiograms were performed in the immediate (median 44 days, n=86), early (median 366 days, n=56) and midterm (median 984 days, n=29) postoperative periods. Result: There were 3 ($2.2\%$) early and 4 ($3.3\%$) late cardiac-related deaths. The mean number of distal anastomoses per patient was 3.34 for total graft and 1.92 for GEA graft. The immediate, early, and midterm GEA patency were 157/159 ($98.7\%$), 106/142 ($94.6\%$), and 53/56 ($94.6\%$), respectively. During follow-up, four patients required percutaneous intracoronary intervention because of GEA and target coronary artery stenosis or competitive flow. Conclusion: These data demonstrate satisfactory clinical and angiographic results in the skeletonized GEA as free graft for total arterial revascularizatioh. Although we need a careful longer follow-up, the skeletonized GEA as a free graft will be a valuable option 'to be' for CABG.

• Journal of Chest Surgery
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• v.39 no.10 s.267
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• pp.759-764
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• 2006

Background: We analyzed post-operative angiography performed in symptomatic patients to evaluate the patency rates and the roles of grafts. Material and Method: We reviewed 52 (15%) coronary angiograms performed for recurrent angina after prior coronary artery bypass surgery from January 1995 to June 2005. A total of 345 patients underwent coronary artery bypass surgery during this period. There were 41 men and 11 women and the mean age was $64.07{\pm}15.58$ years. The median period from operation to re-angiogram was 68.5 months (range, 1 to 126 months). The numbers of grafts and peripheral anastomoses were 42 and 43 for internal thoracic artery (ITA), 14 and 20 for radial artery (RA), and 49 and 89 for saphenous vein. The mean number of anastomosis was 2.9 per patient, Result: The patency rates of ITA, RA and saphenous vein graft (SVG) were 37/43 (86%), 17/20 (85%) and 34/89 (38.2%). The patency rate of arterial grafts was significantly higher than that of SVG (p< 0.001) and the patency rate of the RA was comparable to that of ITA (p=0.942). The patency rate of sequential SVGs was higher than that of single SVG (40.3% vs 31.8%, p=0.478) and the patency rate of proximal segments in sequential anastomosis was higher than that in single anastomsis (55.6% vs 31.8%, p=0.097), but statistically not significant. Conclusion: Arterial grafts have markedly superior patency rates than SVGs, so consideration should be given to the vigorous use of arterial grafts. The patency rate of the RA was comparable to that of ITA.

• Journal of Chest Surgery
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• v.36 no.10
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• pp.734-740
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• 2003

Increasing interest in the use of arterial conduits is based on the better patency of left internal thoracic artery (LITA) than that of saphenous vein (SV) graft and radial artery (RA) is emerging as one of them. We compared the early result of coronary artery bypass grafting (CABG) using UTA and RA (RA group) with CABG using UTA and SV only (SV group). Material and Method: We compared the early operative results of 45 cases in RA group with 45 cases in SV group selected from 165 cases who had CABG between January 2000 and December 2002. The two groups had similar profiles of age, sex, NYHA functional class, left ventricular ejection fraction and coronary angiographic anatomy. We analysed each group on the preoperative risk factors and operative results. Result: There were no statically signigicant difference between groups in operative mortality and each morbidities (stroke, IABP insertion, perioperative MI), respectively. However, the overall incidence of mortality and morbidities was lower in RA group compared to SV group (p < 0.05). RA group (2.93$\pm$0.62 days) had shorter duration of ICU stay than SV group (3.55$\pm$0.95 days) (p<0.001). The patency on postoperative coronary angiography at 7∼14 days after operation in RA group patients were 100% of LITA and RA and 94.9% of SV. Conclusion: We had better early operative results in RA group compared with SV group.