Effect of HTK solution for myocardial preservation.

The aim of this study was to investigate the efficacy of HTK solution for cardioplegia in the continuous 120-minute cross-clamping method in comparison with the conventional GIK method. In an experimental model, the efficacy of ketoglutarate and tryptophan in recovering cardiac function after 6 hours' preservation was evaluated. In Group A, in which ketoglutarate was excluded from the HTK solution, percent developed pressure was significantly decreased (p<0.01) and the released enzyme (CK-MB) was significantly increased, but coronary flow was not significantly changed. In Group B, in which tryptophan was excluded from the HTK solution, a significant decrease in percent developed pressure and coronary flow was seen (p<0.01). This indicated that ketoglutarate and tryptophan were effective in protecting the myocardium during the ischemia. In the clinical study, 54 open heart operations were performed with cardioplegic solution, using either HTK solution or GIK solution. In the HTK Group, the heart was exposed to 120 minutes' of ischemia after the infusion of HTK solution (3L). In the GIK group, intermittent GIK perfusion was performed every 30 minutes in association with continuous cold blood perfusion. Percent fraction shortening and cardiac index were not significantly different. However, CK-MB and HBDH were increased in the GIK group, postoperatively. Histological findings showed deterioration of the mitochondria and myocytes during ischemia in the GIK group. These data suggest that the effect of the cardioplegias in heart preservation was satisfactory in both groups, although the interval of intermittent perfusion was prolonged to 120 minutes in the HTK solution.

[A case report of papillary fibroelastoma of the aortic valve].

A 69-year-old woman was referred to our hospital with an aortic valve tumor. She had shown signs of chronic heart failure due to atrial fibrillation and hypertension for 4 years. There was no history of thromboembolism such as stroke and myocardial infarction, unaccountable fever, weight loss, and systemic symptoms. With two-dimensional echocardiography, a cardiac valve tumor was detected during a routine examination for heart failure. Echocardiographic findings showed a homogeneous mass with a diameter of approximately 1.5 cm, fixed directly to the noncoronary aortic valve cusp. During the operation, a papillary neoplasm, 1.5 by 1 cm, was observed at the midportion of the left ventricular side of noncoronary cusp without a peduncle. The tumor was excised together with all cusps. A 21-mm SJM aortic valve was implanted in position, and thereafter she remained free from symptoms. Histopathological examination of the tumor revealed benign papillary fibroelastoma. Two-dimensional echocardiography was utilized for a diagnosis of the aortic papillary fibroelastoma.

[Preservation of fresh homograft using TC199 solution in rat].

The surgical replacement of human vessels using fresh allografts (homograft) has been reported as useful means. Nevertheless, little is known about preservation effect and immunological consequences using TC199 solution. In this study, defined inbred strains of rats were used. The aorta was extracted from Buffalo rats and preserved for 1, 2, and 3 weeks in TC199 solution at 4 degrees C. The preserved graft was then implanted into the Buffalo rats heterotopically, in the abdominal aorta, in the autotransplant group (AUTO) and into the Lewis rat in the allotransplant group (ALLO). The graft patency and histology including immunohistochemical stain (IgG, IgM, and C3 complement) were assessed at 2 weeks after transplantation. In AUTO, the patency was 100% with grafts 1 and 2 weeks' preservation, and 80% with 3 weeks' preservation. In the ALLO, patency was 100% with grafts with one week's preservation, 80% in those with 2 weeks' preservation and 0% those with in 3 weeks' preservation. Histology revealed that fibroblasts and endothelial cells were significantly deteriorated in 3 weeks' preservation in auto transplantation, however, they were well-maintained in 2 weeks' preservation. In the allo-transplantation group, histological deterioration began after 2 weeks preservation. Immunohistochemical staining showed significant deposits of IgG, IgM and C3 in ALLO. Significant infiltration of antibodies was seen in deteriorated tissue due to prolongation of the preservation periods. These results suggested that freshly preserved allograft was antigenic and 2 weeks preservation using TC199 solution was possible in the rat model.