• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.86-94
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• 1996

Coronary angiography should be performed to verify the patency of bypass graft if coronary artery disease is said to be surgically corrected. Rest/stress myocardial SPECT could be used as a noninvasive alternative to prove patency of bypass graft and functional significance of graft patency by showing improvement of rest perfusion and perfusion reserve after operation. We evaluated the outcome of coronary artery bypass graft surgery by comparing rest/dipyridamole-stress myocardial SPECT before and after operation. Myocardial SPECT were performed $19{\pm}23$ days before and $108{\pm}19$ days after operation in 44 patients(M:F=25:19). Segmental perfusion were scored with 0(normal) to 3(defect) independently for each image set of rest and stress. Perfusion scores were compared between pre and postoperative images. Rest/stress images of pre and post-operative SPECT were compared in paired sets. Postoperative change of perfusion was determined as no change, improvement or aggravation for each artery territory. Postoperative outcome of patients were analyzed. Overall, 74%(158 segments) of 215 segments which had perfusion decrease before operation showed improvement. Among 60 artery territories, 37 territories(62%) improved. Among 42 patients with perfusion decrease in preoperative SPECT, 21 patients(47%) improved after operation. Severe persistent defects improved in 43%(6/14). We concluded that bypass surgery improved myocardial perfusion in dipyridamole stress induced or persistent decrease and that rest/stress myocardial SPECT could be used as a guide for which artery should be operated.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.202-209
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• 2008

Background: The introduction of Drug Eluting Stents (DES) decreased the number of patients referred for coronary artery bypass grafting (CABG). The impact of DES on CABG (Step 1) was studied and compared with the 1-year outcome after CABG with DES (Step 2). Material and Method: Surgical results for patients who underwent off-pump CABG (OPCAB) before the introduction of DES(n=298) were compared with those who underwent OPCAB after the introduction of DES (n=288) (Step 1). Postoperative 30-day and 1-year results were also compared between the patients who underwent percutaneous coronary intervention (PCI) using DES (n=220) and those who underwent OPCAB (n=255) (Step 2). Result: Since the introduction of DES, the ratio of CABG versus PCI decreased. In the CABG group, the number of high risk patients such as elderly patients (age 62 vs. 64, p=0.023), those with chronic renal failure (4% vs. 9%, p=0.021), calcification of the ascending aorta (9% vs. 15%, p=0.043), or frequency of urgent or emergent operations (12% vs. 22%, p=0.002) increased. However, there were no differences in the cardiac death and graft patency rates between the two groups (step 1). During the one-year follow up period, the rate of target vessel revascularization (12.3% vs. 2.4%, p<0.001) and major adverse cardiac events (MACE: death, myocardial infarct, TVR) were higher in the DES than the CABG group (13.6% vs 4.3%) (stage 2). Conclusion: Introduction of DES decreased the number of patients referred for surgery, and increased the comorbidity in patients who underwent CABG. DES increased the rate of target vessel revascularization, and the occurrence of MACE during the 1-year follow-up. However, there was no difference in the incidence of myocardial infarction and cardiac death between the two groups.

• 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.32 no.5
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• pp.433-437
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• 1999

Background: Left main coronary artery (LMCA) angioplasty is another option in the surgical treatment for LMCA disease because of its advantages over the conventional coronary artery bypass grafting (CABG). Material and Method: Between July 1994 and December 1997, 15 patients underwent left main coronary angioplasty for the stenoses of LMCA. There were 8 males and 7 females with the mean age of 53.3${\pm}$8.8 years. The locations of the LMCA stenoses were proximal one-third of the LMCA in 9, middle one-third in 1, distal one-third in 3, and the whole length of the LMCA in 2 cases. Nine patients had peripheral coronary lesions in addition to the LMCA stenosis. The LMCA was approached anteriorly with or without transsection of the main pulmonary artery. The angioplasty was performed with onlay patch widening using an autologous pericardium (14 cases) or saphenous vein (1 case). Additional graftings were required in 9 cases, and both LMCA angioplasty and right coronary ostial angioplasty were done in 1 case. Result: There was no operative mortality. One case needed redo CABG due to the stenosis of the angioplasty site which developed 4 months postoperatively. Coronary angiography was performed in 8 cases one year postoperatively, and revealed good patency of the angioplasty site except for one who showed 50% stenosis at the angioplasty site. No patient complained of angina with a mean follow up of 23${\pm}$11 months. Conclusion: Surgical angioplasty of the LMCA stenosis can be performed in selected cases with safety and good mid-term results.

• 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.5
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• pp.303-308
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• 2003

Background: It has been known that internal thoracic artery grafting has a better patency rate compare to other graft conduits in coronary revascularization. Better patency rates can be expected in more coronary arteries with the use of bilateral internal thoracic artery. However, there were some debates on the complications after the use of bilateral internal thoracic artery. The purpose of our study was to reveal the results of bilateral internal thoracic artery. Material and Method: The 26 coronary artery bypass operations with bilateral internal thoracic artery were performed from July 2001 to May 2002. We compared the results of 8 diabetic patients to those of 18 non-diabetic patients. We compared the results of BITA (bilateral internal thoracic artery) group to those of SITA (single internal thoracic artery) group that were 20 patients and performed during same period. Result: There was no mortality. There was one wound complication in the diabetic group and one in the non-diabetic group. There were no significant differences in operation time, duration of mechanical ventilation, amount of bleeding, infusing duration of cardiotonics, and complication between two groups. There were no significant differences in results between the BITA group and the SITA group. Conclusion: There were no significant differences in early results between the BITA group and the SITA group, and there were no significant differences in results between the diabetic group and the non-diabetic group. We think coronary artery bypass grafting with the use of bilateral internal thoracic artery is considered in diabetic patients.

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.191-196
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• 2005

We analysed the characteristics of anastomotic sites after coronary artery bypass grafting (CABG) using coronary angiographies (CAGs) performed at one and five years postoperatively in the same patient population. Material and Method: Among the 219 patients who underwent isolated CABGs between January 1995 and December 1997, follow-up coronary angiograms were performed in 149 ($75.3\%$) patients at one year and in 115 ($58.1\%$) patients at five years postoperatively. FitzGibbon grading system was used to evaluate the anastomotic sites. Result: The patency rates of arterial grafts at one- and five-year were $96.5\%$ (192/199) and $93.1\%$ (134/144), which were higher than those of saphenous vein grafts (SVGs) ($82.9\%$ (224/270) and $77.5\%$ (141/182), respectively) (p=0.01). Although there were significant decreases in the patency rates between one- and five-year CAGs of both arterial and venous grafts, the proportion of FitzGibbon grade B among the SVGs was increased from $5.2\%$ (one-year) to $8.2\%$ (five-year), suggesting the progression of vein graft disease (p < 0.01). Conclusion: The patency rate of the arterial graft was higher than that of SVG in both one- and five-year CAGs. The attrition rate of saphenous vein graft was higher than arterial grafts.

• Journal of Chest Surgery
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• v.35 no.3
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• pp.182-187
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• 2002

Background: There have been many reports of coronary angiographic findings after coronary bypass grafting, most of which are focused on the graft patency rate of the bypass conduits. However, postoperative angiography can provide numerous informations other than patency rates that are useful for establishing operative strategy. Material and Method: We studied 73 patients in whom coronary angiography was done after more than 1 month of CABG. Mean interval from the operation to coronary angiography was 10.6 months and the reasons for coronary angiography follow up were residual or recurrent angina in 54 patients, abnormalities on myocardial perfusion scan or echocardiography in 13 patients, and for simple follow up in 6 patients. Result: Overall graft patency rate was 80.9% (internal thoracic artery 100%, saphenous vein 75.0%) in patients of simple follow up and 61.6%(internal thoracic artery 81.1%, saphenous vein 55.3%) in patients with ischemia. Progression of native coronary arterial disease proximal to the grafting site was found in 50 patients(68.5%). Among 201 coronary arterial branches that had not been completely occluded preoperatively, ninty five branches(47.3%) revealed progression of diameter stenosis by more than 20% on the follow up study. Among them, 64 branches(31.8%) progressed to total occlusion. The incidence of disease progression was highter in the coronary arteries with patent grafts(57.5%) than in those with occluded grafts(36.3%)(p<0.05), Comparing internal thoracic artery graft with saphenous vein graft, internal thoracic artery was superior to saphenous vein, not only in terms of patency(83.3% vs 56.6%), but also in terms of result of later percutaneous intervention success rate(100% vs 62%, p<0.05). Conclusion: Due to the considerable incidence of progression of native coronary artery stenosis in the early postoperative periods, bypass grafting of a vessel with borderline stenosis, especially with vein graft, must be done prudently. And it was confirmed again that revascularization of left anterior descending artery is most important and that internal thoracic artery was superior to saphenous vein.

• Journal of Chest Surgery
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• v.32 no.11
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• pp.1009-1016
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• 1999

Background: Minimally invasive direct coronary artery bypass surgery(MIDCAB) has been increasing in interest along with the new techniques in myocardial immobilization for easier and safer procedures. Until the opening of the era of new techniques, adequate accuracy and good patency of grafts were debatable. Our experiences of MIDCAB were studied according to the stages of technical developments. Material and Methods: Since March 1996, 55 patients have undergone MIDCAB procedures. The patients of off-pump CABG(no cardiopulmonary bypass under full sternotomy) were excluded from the study. In the early experience(Stage I), a left anterior small thoracotomy through the left parasternal incision was performed(n=6); then an approach through the lower partial sternotomy was used(Stage II, n=33); and recently, a chest wall elevator for harvesting the internal thoracic artery and the foot plate for myocardial immobilization have been used(USSC, Norwalk, CT)(Stage III, n=16). Result: The surgical procedures of four patients in the Stage II group have been converted to conventional bypass because of the deeply seated left anterior descending coronary artery in two patients, fracture of the calcific lesion in the right coronary artery in one patient, and a cardiogenic shock during hypothermia in the other patient with ventricular dysfunction. Two patients in stage II experienced symptomatic recurrences after surgery and restenosis was verified on angiocardiography. They were managed by interventional procedures. All the other patients were doing well without symptoms, except one patients in Stage II who underwent PTCA procedure for a lesion in the circumflex artery during the follow up period. Conclusion: The new and specialized devices are essential to the development of MIDCAB surgery. MIDCAB and the hybrid procedures in multi-vessel disease are on the way to further development. So far, our experience is limited only to a single device among the many new devices for the purpose.

• 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.