• Journal of Chest Surgery
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• v.37 no.4
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• pp.322-327
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• 2004

Coronary artery bypass grafting on the beating heart is no longer a new methods for any cardiac surgeon. We evaluated the application of the off-pump coronary artery bypass procedure relative to safety and efficiency as measured by postoperative complication and operative mortality. Material and Method: We used our retrospective database to compare the patients having off-pump coronary surgery (n=100) with those having on-pump coronary surgery (n=100) between June, 1999 and August, 2002. Patients whom underwent associated valvular or aortic aneurysmal operation were excluded. Result: Neither groups showed any differences in the patient's risk factors and extent of coronary disease. Off-pump CABG group did not have significantly less mean operation time (295$\pm$73 min vs 323$\pm$83 min, p=ns) and mean hospital day (15.34$\pm$6.02 day vs 13.80$\pm$4.95 day, p=ns). However, off-pump CABG group had significantly shorter mean ventilation time (17.3$\pm$11.27 hour vs 24.98$\pm$16.1 hour, p＜0.05). No patients were converted to on-pump CABG in off-pump CABG. Intraoperative hemodynamic instability in off-pump CABG were 6 cases, of whom 2 cases were in lateral wall approach and 4 cases in right coronary anastomosis. Postoperative mortality was 1 case in off-pump CABG and 2 cases in on-pump CABG. Intra-aortic ballon pump (IABP) was applied in 1 case with off-pump CABG and in 2 cases with on-pump CABG. No patients presented postoperative cerebral infarction ＆ stroke in off-pump CABG but 2 patients in on-pump CABG. Postoperative arrhythmia presented in 4 cases with off-pump CABG and in 6 cases with on-pump CABG. Acute renal failure (ARF) was complicated in 3 cases with off-pump CABG and in 2 cases with on-pump CABG. Conclusion: This study documented the immediate safety and efficiency of the off-pump CABG procedure.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.480-483
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• 1999

The widely accepted method for coronary artery bypass grafting(CABG) is performing the distal coronary artery anastomoses on the flaccid and nonbeating heart with the aid of cardiopulmonary bypass(CPB) and cardioplegic arrest. However, current cardioplegic techniques are not consistent in avoiding myocardial ischemic damages especially in high risk patients undergoing CABG. In this regard, "Off-Pump" seems to be an ideal method for preventing myocardial ischemic damage and adverse effects during CPB. However, "Off-pump" CABG is not always technically feasible. We report 2 cases of "On-pump" CABG performed on the beating heart in high risk patients; The first patient had left ventricular dysfunction(Ejection Fraction=25%), and the second patient had cardiogenic shock after percutaneous transluminal coronary angioplasty.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.877-883
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• 1998

Background: Cardiopulmonary bypass(CPB), a standard adjunct for open heart surgery, can also play an important role in treating patients with noncardiac diseases. Material and Method: We report a collective analysis of noncardiac applications of cardiopulmonary bypass experienced at Seoul National University Hospital from 1969 to 1996. Out of a total of 20 patients, 8 were treated for membranous obstruction of inferior vena cava(MOVC), 5 for malignant melanoma, 3 for pulmonary embolism, 1 for double lung transplantation, 1 for intracranial giant aneurysm(GA), 1 for renal cell carcinoma(RC), and 1 for liposarcoma. CPB was used to induce profound hypothermia with circulatory arrest in 6 patients(MOVC 4, GA 1, RC 1). Result: CPB time was 113 mins on average for MOVC, 161 mins for GA, and 156 mins for RC, while the lowest rectal temperature was 26$^{\circ}C$ on average in MOVC, and 19$^{\circ}C$ in GA and RC. Postoperative recovery was good in all MOVC patients. The patient with GA, who underwent reoperation for the removal of hematoma, died 14 days postoperatively. The patient with RC recovered from the operation in a good condition but died from metastatic spread 6 months later. CPB was instituted for pulmonary embolectomy in 3 patients, in whom postoperative courses were uneventful, except in 1 patient who showed transient neurologic symptoms. CPB was used in a patient with double-lung transplantation for hemodynamic and ventilatory support. The patient was weaned successfully from CPB but died from low output and septicemia 19 days postoperatively. CPB without circulatory arrest was used to treat in 4 patients with MOVC. These patients showed good postoperative courses. CPB was used to administer high concentrations of chemotherapeutic agents to the extremities in 6 patients(malignant melanoma 5, recurrent liposarcoma 1). CPB time was 153 mins on average. No complications such as edema and neurologic disability were found. Conclusion: Although CPB has a limited indication in noncardiac diseases, if properly applied, it can be a very useful adjunct in a variety of surgical cases.

• Journal of Chest Surgery
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• v.30 no.7
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• pp.677-685
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• 1997

Thromboelastography(TEG) is the unique measure that gives rapid information about the whole clotting process. Simplifying the diagnosis of coagulopathy during operations, TEG can provide an adequate therapy for postoperative bleeding. Remarkable improvement in hemostasis after cardiopulmonary bypass(CPB) has been achieved by the treatment with proteinase inhibitor aprotinin, but the hemostatic mechanism of aprotinin during CPB is still unclear. This study was designed to evaluate the effects of aprotinin on coagulation system during CPB by using TEG. Forty patients who underwent CPB were divided into two groups: aprotinin(2u 106 kallikrein inhibition units, as a single dose into the cardiopulmonary bypass priming solution) treatment group(male 14, female 8, mean age=50.Byears) and no aprotinin treatment(control) group(male 10, female 8, mean age=53.4 years). TEG, activated clotting time, prothrombin time, activated partial thromboplastin time, platelet counts, fibrinogen an (ibrinogen degradation product(FDP) concentrations were checked before and after CPB(30 minutes after neutralization of heparin effect by protamine sulfate). There was no significant difference in other conventional coagulation tests of two groups except postcardiopulmonary bypass FDP concentration in control group, which was significantly increased compared to that in aprotinin group(p<0.05). In TEG variables of both groups, clot formation time(K) and alpha $angle(\alpha^{\circ})$ were significantly increased and decreased, respectively, after CPB(p<0.05), but fibrinolytic index(LYS60) was not changed during CPB. In aprotinin group, reaction time(R) was decreased significantly after CPB(p<0.05) but maximum amplitude(MA) was not changed(p>0.05). On the contrary, R was not changed markedly but MA was decreased significantly in control group after CPB(p<0.05). This result shows that main change in coagulation system during CPB is not hyperfibrinolysis but cecrease in clot strength by platelet dys unction, and the main effect of aprotinin during cardiopulmonary bypass is the maintenance of clot strength to the pre-CPB level by the preservation of platelet function.

• Journal of Chest Surgery
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• v.39 no.7 s.264
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• pp.505-510
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• 2006

Background: Small animal cardiopulmonary bypass (CPB) model would be a valuable tool for investigating path-ophysiological and therapeutic strategies on bypass. The main advantages of a small animal model include the reduced cost and time, and the fact that it does not require a full scale operating environment. However the rat CPB models have a number of technical limitations. Effective maintenance and control of core temperature by a heat exchanger is among them. The purpose of this study is to confirm the effect of rectal temperature maintenance using a heat exchanger of cardioplegia system in cardiopulmonary bypass model for rats. Material and Method: The miniature circuit consisted of a reservoir, heat exchanger, membrane oxygenator, roller pump, and static priming volume was 40 cc, Ten male Sprague-Dawley rats (mean weight 530 gram) were divided into two groups, and heat exchanger (HE) group was subjected to CPB with HE from a cardioplegia system, and control group was subjected to CPB with warm water circulating around the reservoir. Partial CPB was conducted at a flow rate of 40 mg/kg/min for 20 min after venous cannulation (via the internal juglar vein) and arterial cannulation (via the femoral artery). Rectal temperature were measured after anesthetic induction, a ter cannulation, 5, 10, 15, 20 min after CPB. Arterial blood gas with hematocrit was also analysed, 5 and 15 min after CPB. Result: Rectal temperature change differed between the two groups (p<0.01). The temperatures of HE group were well maintained during CPB, whereas control group was under progressive hypothermia, Rectal temperature 20 min after CPB was $36.16{\pm}0.32^{\circ}C$ in the HE group and $34.22{\pm}0.36^{\circ}C$ in the control group. Conclusion: We confirmed the effect of rectal temperature maintenance using a heat exchanger of cardioplegia system in cardiopulmonary bypass model for rats. This model would be a valuable tool for further use in hypothermic CPB experiment in rats.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.867-872
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• 1998

Background: The fixed dose regimen with activated coagulation time(ACT) is the most commonly employed method for determining the required dosage of heparin and protamine during cardiopulmonary bypass(CPB). Material and Method: We performed a prospective study on a fixed dose regimen for analyzing adequate dosages of heparin and protamine, the incidence of heparin resistance and heparin-induced thrombocyt openia, factors affecting ACT during CPB, and changes of ACT during aprotinin usage. 300 units/kg of heparin were administered to patients, and ACTs were measured after 5 mins. ACTs were checked at 10 mins and 30 mins after the onset of CPB, and then at 30 min intervals thereafter. If the measured ACT was under 400 secs, we added 100 units/kg of heparin. The heparin was reversed with 1 mg of protamine for each 100 units administered. If the measured ACT was longer than 130 secs 30 mins after protamine administration or if there was definitive evidence of a coagulation defect, we administered a further 0.5 mg/kg of protamine. Result: We studied 80 patients(50 adults and 30 children) who underwent open heart surgery(OHS) at Seoul National University Hospital. Preoperative ACT was 114.3${\pm}$19.3 secs in adults, and 119.5${\pm}$18.2 secs in children. There were no differences in preoperative ACT due to age, body weight, body surface area, or sex. The preoperative ACT was not influenced by a positive past history of OHS. Ten adults(20%) and 3 pediatric patients(10%) needed additional doses of heparin to maintain the ACT above 400 secs. Additional protamine administration was needed in 9 adults(18%) and 10 children(33%). Heparin resistance was found in only two adults. Heparin-induced thrombocytopenia was detected in 2 adults and 1 child. During CPB, ACT was prolonged. 12 adult patients received a low dose of aprotinin and showed longer celite activated ACT compared to the control group.The kaolin activated ACT showed a lower tendency than the celite activated ACT in aprotinin users. Conclusion: In conclusion, fixed dose regimen of heparin and protamine can be used without significant problems, but the incidence of need of additional dosage remains unsatisfactory.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.245-251
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• 2004

Hemostatic function is regarded to be preserved after an off-pump coronary artery bypass grafting (CABG), compared to conventional CABG, and the preserved hemostatic function may increase thrombotic occlusion of the graft. We studied the changes of hemostatic variables in patients undergoing off-pump CABG, and compared to those of on-pump CABG. We studied the changes of coagulation function in 11 patients who underwent off-pump CABG (group I), and compared them with those of 11 patients who underwent on-pump CABG and Dor procedure (group II). Coagulation status was evaluated by thromboelastography and blood coagulation test preoperatively, postoperative 1$^{st}$ day, 2$^{nd}$ day, 3$^{rd}$ day, and 5$^{th}$ day, respectively. Among the variables measured by thromboelastography (such as r time, k time, $\alpha$ angle, and MA value) and blood coagulation test (such as factor Ⅶ, protein S, protein C, antithrombin III, activated protein C resistance test, plasminogen, D-dimer, prothrombin time, activated partial thromboplastin time, platelet count, hemoglobin, and fibrinogen), there were significant differences in the MA value, $\alpha$ angle, and platelet counts between the two groups. MA values were 140$\pm$72% and 153$\pm$98% in group I, and 87$\pm$27% and 78$\pm$28% in group II, at postoperative 3$^{rd}$ and 5$^{th}$ days, respectively (p<0.05). $\alpha$ angle was 122$\pm$92% in group I and 69$\pm$23% in group II at postoperative 3$^{rd}$ day (p=0.09). Platelet count was 63$\pm$55% in group I and 33$\pm$13% in group II at postoperative 3$^{rd}$ day (p<0.05). Patients who underwent off-pump CABG showed increased coagulability during postoperative periods, compared to those who underwent on-pump CABG. Our data suggest that aggressive perioperative anticoagulation therapy is warranted in patients undergoing off-pump CABG. CABG.

• Journal of Chest Surgery
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• v.33 no.12
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• pp.941-947
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• 2000

Background: Central nervous system complication after coronary artery bypass grafting(CABG) is one of the major prognostic determinants and the use of the cardiopulmonary bypass(CPB) may increase the incidence of this devastating complication. In this study, the outcomes after off-pump CABG were studied and compared with those following the conventional CABG using CPB. Material and Method: Among the consecutive isolated CABG's performed in SNUH during Feb. 1995 and Jun. 1999, 338 coronary artery bypass grafting were divided into two groups. 223 patients underwent CABG using the CPB(Group I), and 115 patients underwent CABG without CPB(OPCAB)(Group II). All patients enrolled in this study received extensive preoperative examinations including thorough neurologic examination before and after surgery, transcranial doppler study, carotid duplex ultrasonography, and magnetic resonance angiography if necessary. Central nervous system(CNS) complications were defined as stroke, seizure, metabolic or hypoxic encephalopathy and transient delirium after surgery. Result: There were 61 cases(27.3%) who developed postoperative CNS complication in Group I, whereas 8 cases(7.0%) of CNS complications developed postoperatively in group II(p<0.05). Statistically significant predictors of postoperative CNS complications in group I were age and the use of cardiac assist devices perioperatively. Conclusion: This study suggested that omitting the use of CPB in CABG resulted in significant decrease of the postoperative CNS complications. OPCAB should be more widely applied especially to the elderly who have preexisting cerebrovascular disease.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.510-516
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• 1996

Cardiopulmonary bypass cannulas are usually characterized by the French number. However this de- scription provides only the external diameter of the cannula, which gives no information about the press- ure-flow characteristics of the cannula itself. A standardized system to describe the pressure-flow characteristics of a given cannula has recently been proposed and has been termed the M-number It is reported that the pressure-flow characteristics of a particular cannula can be determined from a novo- gram or chart, if the experimentally derived M-number of the cannula is known. In this regard, we conducted an investigation to analyze correlation between experimentally and clinical y derived M-numbers using three different sizes of pediatric aortic cannulas in fifty cardiac patients on cardiopulmonary bypass. The clinical and experimental M-numbers showed a strong correlation. The clinical M-numbers were typically 0.)5 to 0.55 greater than the experimental M-numbers. The clinical M-numbers also showed an inverse relationship to the temperature change of the patient, most probably due to an increase in blood viscosity from hypothermia. This inverse clinical M-numbersltemperature re- lationship was more marked in higher M-number cannulas. The clinical data obtained in this study suggest that the experimentally derived M-numbers correlated strongly with the clinical performance of the cannula with the significant influence of the temperature.

• Journal of Chest Surgery
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• v.35 no.7
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• pp.553-555
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• 2002

Transabdominal approach in redo coronary artery bypass grafting(CABG) may avoid the risk related to repeat sternotomy. Redo CABG using this approach can be performed safely in selected cases. We report a case of redo off-pump CABG through a transabdominal approach in a 59-year-old woman with recurrent unstable angina after a previous CABG. Through a curvilinear epigastric incision, right gastroepiploic artery(RGEA) was harvested as a graft, and the RGEA-to-right coronary artery anastomosis was performed on the beating heart. A 1-day postoperative angiographic study showed the patent RGEA graft, and she was discharged on postoperative 4th day without any complication.