• Journal of Chest Surgery
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• v.43 no.6
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• pp.576-587
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• 2010

Background: Effective decellularization and fixation process is critical, in order to use xenogenic valves clinically. In the present study, we decellularized bovine pericardium using sodium dodecyl sulfate (SDS) and N-lauroyl sarcosinate, treated with $\alpha$-galactosidase, and then fixed in various manners, to find out the most effective tissue preservation & fixation procedure. Material and Method: Bovine pericardium was decellularized with SDS and N-lauroyl sarcosinate, and treated with $\alpha$-galactosidase. Both groups were fixed differently, by varying glutaraldehyde (GA) or EDC (1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide)/N-hydroxysuccinamide (NHS) treatment conditions. Thereafter, physical examination, tensile strength test, thermal stability test, cytotoxicity test, pronase test, pronase-ninhydrin test, purpald test, permeability test, compliance test, H&E staining, DNA quantification, and $\alpha$-galactose staining were carried out to each groups. Result: GA fixed groups showed better physical properties and thermal stability than EDC/NHS fixed groups, EDC/NHS-GA dual fixed groups showed better physical properties and thermal stability than EDC/NHS fixed groups, and showed better thermal stability than GA fixed groups. In pronase test and pronase-ninhydrin test, GA fixed groups and EDC/NHS-GA dual fixed groups showed stronger crosslinks than EDC/NHS groups. Permeability and compliance tended to increase in EDC/NHS-GA dual fixed groups, compared to GA fixed groups. But, EDC/NHS-GA dual fixed groups had stronger tensile strength and lower cytotoxicity than GA fixed groups. Conclusion: We have verified that EDC/NHS-GA dual fixation can make effective crosslinks and lower the toxicity of GA fixation. Henceforth, we will verify if EDC/NHS-GA dual fixation can lower calcifications & tissue failure in vivo experiment.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.383-389
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• 1997

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60$\pm$5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class 111 in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4$\pm$4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 $\pm$8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5$\pm$ 1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 $\pm$ 13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1197-1204
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• 1997

Between April 1981 and June 1996, 65 patients had aortic root replacement at our institution. Disease entities were pure aortic annuloectasia in 31 patients(47.7%), Stanford type A aortic dissection with annuloectasia in 8(43.1%), atherosclerotic aneurysm with aortic regurgitation in 4(6.2%), and paravalvular leakage after aortic valve replacement in 2(3.1 %). 34 patients(52.3%) had the clinical stigmata of the Marfan syndrome. The operative procedures were Bentall operation in 61 patients(93.8%); 3 of conventional procedure and 58 of Cabrol's modification, aortic valve-sparing operation in 2(3.1 %), and root replacement with homograft in 2(3.1%). Hospital deaths occurred in 3 patients(4.8%) because of uncontrolled bleeding(1) and bypass weaning failure due to low cardiac output(2), and all had emergency operation with Cabrol's procedure. Postoperative complications developed in 19(29.2%) patients and most of them were transient. Surviving 62 patients have been followed up to cumulative total 315.0 patient-years(mean 60.2 $\pm$42.4 months). Late deaths occurred in 7 patients(11.3%), aneurysmal changes of remaining aorta were detected in 12 patients(19.4%). Actuarial survival rate at 10 years was 72.0 $\pm$ 9.7%, and the subsequent aortic operation-free rate at 10 years was 68.0$\pm$ 8.9% In a multivariate analysis, Marfan syndrome, emergency operation, preoperative dissection, combined arch replacement, and total circulatory arrest emerged as significant risk factors for hospital death or subsequent aortic operation. Over 60 years of age was the only risk factor for late death. Our 16 years'cummulative experience shows that aortic root replacement, mainly by means of Cabrol's procedure, can be applied successfully to variety of aortic root disease. However, long-term follow up will be needed to determine the late result of aortic valve-saving operation and root replacement with homograft. When dissection is present or the distal native aorta is diseased in'Marfan patients, close follow-up is necessary because of the subsequent aneurysmal change of remaining aorta.

• Journal of Chest Surgery
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• v.31 no.2
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• pp.118-124
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• 1998

Minimally invasive coronary artery bypass grafting without using cardiopulmonary bypass (CPB) is a recently accepted modality of myocardial revascularization prcedures which is particularly suitable to the patients with lesions in the left anterior descending(LAD) and the right coronary arteries. Of the consecutive 35 patients of coronary artery bypass grafting performed at Sejong General Hospital from March to August 1996, six patients underwent minimally invasive coronary artery bypass grafting without CPB. All had stenotic lesions of the LAD more than 90%. Bypass grafting of the LAD was approached through midline sternotomy in one, through ministernotomy in two, and through limited left anterior thoracotomy in three patients, respectively. The internal mammary arteries were prepared without the use of thoracoscope. The mobilized mammary arteries were connected directly to the LAD in 5 patients, and the anastomosis required interposition of a segment of the radial artery in the remaining one. The diagonal branch was revascularized with the saphenous vein graft at the same time in one patient. No blood transfusion was necessary in 2 patients, and average blood required during surgery was 800ml in 4 patients. All patients were extubated from 4 to 14 hours(mean 9 hours) after operation. Early postoperative coronary angiography in 5 patients between 7 and 10 days after surgery has proved full patency of the grafts. With these limited clinical experiences, the clinical results demonstrated that minimally invasive coronary artery bypass grafting without CPB is an useful procedure especially in patients with isolated lesion in the proximal LAD.