In order to reduce the blood transfusion volume in open heart surgery, the new blood autotransfusion technique using cardiotomy reservoir unit BCR 3538, which was configured to serve also as a receptacle for postoperative mediastrinal drainage, was introduced. To investigate the utility and the problem in this system, every clotting factor, platelets' function and the extent of the hemolysis were measured serially both in patients' arterial blood and the shed mediastinal blood. The bank blood transfusion was significantly reduced to 250ml±330ml by this system compared to the 1080ml±820ml in the cases of usual system (p<0.01). Every clotting factor recovered well in patients' arterial blood after cardiopulmonary bypass (CPB). In the reservoir blood, the clotting factor IX, XI, XII were extremely suppressed at 1h CPB, and 3h after the CPB, every clotting factor except fibrinogen (42±28mg/dl) showed the quite higher activity, such as factor VIII 400%, IX 365%, XI 72%, XII 267%. Namely, the anticoagulability of the reservoir blood was maintained due to the effect of the residual heparin at 1h after the CPB, and due to the contact defibrinogation of the shed mediastinal blood at 3h after CPB. The free hemoglobin level was extremely high on the reservoir blood at 3h after CPB. In 6 cases, the autologous blood retransfusion was abandoned by clott formation in the unit because of the contamination of the intraoperatively used fibrin glue. From this study, the autologous blood transfusion using cardiotomy reservoir BCR 3538 was useful not only for saving the transfusion of the bank blood but also the hemostasis after CPB. But to reduce the hemolysis in this system, and to establish the safety against the other clotting material such as fibrin glue were the problems which should be resolved in future. I appreciate the kind support of Alexander von Humboldt Foundation for this study.

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A cervical aortic arch is a very rare congenital malformation of aortic arch. A case is reported of a 42-year-old woman with an extensive circular aneurysm of a left-sided cervical aortic arch. The arch aneurysm was successfully removed surgically and replaced with woven Dacron graft. Histologic examination of the aneurysm revealed atherosclerosis and intimal defect.

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A 57-year old woman with a left renal aneurysm in a solitary kidney was successfully treated by in situ aneurysmectomy under careful renal preservation (intermittent perfusion combined with topical cooling). In our knowledge, 219 cases of renal aneurysms have been reported in the Japanese literatures by 1987. Among those cases, only 9 cases including our case were noted to have a solitary kidney. Surgical repair was recommended for renal aneurysm, especially, in a solitary kidney because of the high incidence of nephrectomy when ruptured.

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A low power carbon dioxide laser was used to perform 110 end-to-end laser-assisted microvascular anastomoses of carotid arteries in ginea pigs and rabbits. In 56 of 72 cases which were irradiated with power output 20-40mW, energy density 1.5-2.5J/mm², showed patency immediately after surgery with no wound distruption nor thrombus formation. From these results, the optimum condition for anastomosis seemed to be in this range of power output and energy density. The bursting strength of laser-assisted anastomosis (LA) was assessed and compared with conventional suture anastomosis (CA). LA arteries consistently demonstrated lower bursting strength than those of CA. Relatively low bursting strengths at 1 hour and 3 days in the LA with 3 stay sutures may explain the late aneurysm formation. Additional stay suture seemed to prevent such complication. The mean duration of each anastomosis was 13min for the LA repairs compared to an average of 24min for CA repairs. These findings suggest that a low power carbon dioxide laser has potential clinical application for anastomosis of small vessels.

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Recently, laser has been widely applied in the field of medicine and surgery. However, laser application is very rare in the cardiovascular surgery through world. Among the patients with ischemic heart disease there are some cases for whom aortocoronary bypass could not be carried out, because of small branches and diffuse stenoses of the coronary arteries. Besides, there are some problems in keeping long-term patency after vascular anastomosis especially for small-caliber vessels. For resolving these problems we have performed and continued to achieve laser works concerning, 1) myocardial revascularization by laser, 2) laser vascular anastomosis, 3) laser angioplasty. Subsequently, myocardial revascularization by high energy CO₂ laser could be successfully carried out experimentally. It was microscopically clarified that transventricular laser channels newly created in the ischemic myocardium were patent even 3 years after surgery. On the basis of excellent results of experimental studies laser was successfully employed in a 55 year-old male patient who had severe anginal attack and 90% stenosis of the left anterior descending coronary artery. On the other hand, vascular anastomosis by low energy CO₂ laser (out put 20-40mW, irradiation time 6-12s/mm) was satisfactorily utilized in 83 patients with intermittent claudication, chronic renal insufficiency and angina pectoris after a feasibility of the procedure was clearly confirmed by hemodynamic and histological examinations. Finally, laser angioplasty using Argon laser was fundamentally studied in the mongrel dogs and human cadaver. Based on the successful results of these studies, laser angioplasty was clinically applied in the 17 patients with multiple coronary stenoses or severe stenoses of the peripheral arteries. From these excellent results, laser application was inevitable for treatment in the field of cardiovascular surgery. Clinical experience of 101 patients treated by laser was reported in detail.

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The surface-coated vascular stent of shape memory alloy was made for use of occlusion of pseudo-lumen of the dissecting aneurysm of the aorta, as the usage of shape memory alloy in angioplasty, and the metal flexible delivery catheter was also made for the introduction of the stent. In the present study, antithrombogenicity of the vascular stent was much improved by surface-coating with EPTFE and segmented polyurethane. The long-term usage of the stent was confirmed by radiological, macroscopic, and electron microscopic examinations. Moreover, the metal flexible delivery catheter was demonstrated to be of much benefit for the introduction of the surface-coated vascular stent of shape memory alloy.

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