Single administration of warfarin at 0.1mg/kg was carried out at an early stage after cardiac operation, and changes in the blood vitamin K levels, blood coagulation factors and the blood warfarin levels within 24 hours of administration were evaluated to determine an ideal mode of initiating the administration and the initial dose in warfarin therapy at an early postoperative stage. The study group consisted of 30 postoperative cardiac cases, and 20 healthy individuals as controls. The results showed that anticoagulant effects cause close to the therapeutic range within 24 hours of administration of oral warfarin therapy in prothrombin time of the postoperative cases. As regards the blood vitamin K levels, both vitamin K₁ and K₂ levels were more depressed in the subjects than in the control group. Differences in the vitamin K level seemed to play a key role in the difference in anticoagulability between the two groups. It was thus implied that the risk of an abrupt decline in coagulability and a decrease in the level of vitamin K parallels the starting level of warfarin instituted in the wake of a cardiac operation. To conclude, safe and effective warfarin therapy should be started at a 0.1mg/kg dosage level at an early stage after the cardiac operation.

Laser thermal angioplasty with a metal hot tip probe for atherosclerosis obliterans of iliac, femoral and popliteal artery lesions was used instead of conventional balloon angioplasty. Initial angiographic and clinical success was achieved in 24 of 28 (85.7%) vessels. The 1-year cumulative patency rate was 82.6 % of 19 vessels with clinical success in 23 vessels (one of 24 clinical success cases died due AMI at 14 days after operation). In the 8 iliac and 15 femoro-popliteal arteries, the cumulative success rates were 100% and 73.3%, respectively. Complications were observed in 25% of vessels (7 of 28 vessels). One of them necessitated emergency bypass surgery but not the others. In the 24 laser thermal angioplasty, other revascularization methods were performed on 12 cases (50%) at the same time. Although many problems remain to be solved laser thermal angioplasty can be effective for atherosclerotic disease.

Preoperative factors associated with serum haptoglobin levels in 35 patients before open heart surgery were evaluated, and the relationship between the incidence of hemoglobinuria with cardiopulmonary bypass (CPB) and preoperative haptoglobin level were analyzed. Inflammation increased haptoglobin levels, but the level of 2-2 type of haptoglobin were lower than those of other types of haptoglobin. In valvular disease, 5 of 6 patients with valvular sclerosis of the aortic valve had reduced haptoglobin levels and two patients had anhaptoglobinemia. Hypohaptoglobinemia seemed to be observed more frequently in aortic valvular disease than in mitral valvular disease. During CPB, serum hemoglobin increased at 0.36mg/dl/min, but haptoglobin levels at the initiation of CPB decreased to less than 30% of preoperative levels, therefore, for similar periods of CPB, the incidence of hemoglobinemia in patients with preoperative hypohaptoglobinemia was higher than in patients without preoperative hypohaptoglobinemia. Preoperative haptoglobin determination is required in candidates for open heart surgery, and haptoglobin administration is recommended in patients with hypohaptoglobinemia.

An internal felt-reinforced patch-plasty was performed in 11 patients with dissecting aortic aneurysm (DeBakey type I: 4 cases, type II: 1 case, type III: 5 cases, aortic arch dissection: 1 case). The aortic cross-clamp time was 84±19 min on the average. The initial tear of the aortic intima was closed on 10 patients. Minor leakage through a felt inserted in the false lumen was observed in one patient of type I. There was no operation-related death except one patient of type III who died from arrythmia encountered following termination of centrifugal pump bypass. Thrombotic occlusion of the false lumen developed in the ascending aorta in type I and II cases, and in the desceding aorta in type III one month after operation. The false lumen localized in the aortic arch was completely occluded by thromi. Postoperative course was excellent in all patients after 16 months on the average. Internal felt-reinforced patch-plasty is a simple and reliable procedure for closing the intial tear of dissecting aortic aneurysms.

Massive thrombi are sometimes present in aortic aneurysms, which cause severe complication such as distal arterial thromboembolism, and greatly influence the prognosis. Such thrombi can be easily detected by CT scan and ultrasound. However these imaging techniques can only demonstrate the presence of thrombi, and are not able to indicate these activity. We performed ¹¹¹In-labeled-platelet scintigraphy (platelet scinti.) in 27 cases of aortic aneurysms (13 true aneurysms and 14 dissecting aneurysms) and 13 postoperative cases of dissecting aneurysms, and compared the findings of CT scan. In some cases, the findings of platelet scinti. were markedly different from the findings CT scan. And our results suggested that the radioisotope deposit revealed by platelet scinti. was reflected thrombotic activity. In one case of dissecting aneurysm, marked RI deposit was revealed by platelet scinti., and subsequently the false lumen was occluded. One postoperative case of dissecting aneurysm showed marked RI deposit and, distal arterial thromboembolism developed. ¹¹¹In-labeled-platelet scintigraphy is thought to be useful to estimate thrombotic activity in aortic aneurysm, and to predict complications and the prognosis.

We perfomed an aortic valve replacement and intraoperative plasma exchange with Cell Saver 4^® made by Haemonetics for removal of bilirubin. Diluted blood after cardiopulmonary bypass and suctioned blood (total volume 11, 300ml) was washed, concentrated and transfused. Plasma bilirubin level was decreased to 5.4mg/dl from 9.9mg/dl during operation. It was concluded that intraoperative plasma excange with Cell Saver 4^® was safe and effective technique for removal of bilirubin during open heart surgery.