Laser-assisted vascular anastomosis (LAVA) of arteries and veins in mongrel dogs was performed using a low-powered carbon dioxide laser. The anastomotic site was irradiated at a point 10mm distal from focus and the beam at this point was 0.8mmφ in diameter. Adequate laser power for anastomosis was 160-200mW for arteries and 120-160mW for veins, and the required duration of radiation was 5-10sec per 1mm anastomotic length for both vessels. In arteries successful anastomosis was achieved by LAVA in 44% of transverse incisions and 65% of longitudinal incisions, compared to 65% and 95% for veins, respectively. LAVA ruptured at a pressure of 102±28mmHg on average in arteries and 77±24mmHg in veins. However, LAVA reinforced with etyl 2-cyanoacrylate were safe at high pressures more than 300mmHg in arteries. Follow up has been achieved in 99 anastomotic sites for 9 months. No stenosis, occlusion, thrombus or infection were found apart from one (1%) pseudoaneurysm formation 4 months after LAVA. Angioscopic views and histological findings of anastomotic tissue welded by mean of LAVA revealed good layer-to-layer continuity of the three-layer structure of arterial wall. LAVA seems to be a useful method for vascular anastomosis.

In a 3 year-old girl with acyanotic tetralogy of Fallot, preoperative echocardiography revealed a thick fibrous tissue hanging on the right side of large ventricular septal defect. According to the definition of Kirklin, we diagnosed it as “flap valve ventricular septal defect.” And this diagnosis was supported by the findings of electrocardiogram and cardiac catheterization. At the operation, it was confirmed that the flap was only attached to the posterior margin of ventricular septal defect, and that it hardly played any part in tricuspid valve function. To our knowledge, this is the first case of “tetralogy of Fallot with flap valve ventricular septal defect” reported in Japan.

Eighty-three patients with valular heart diseases underwent exercise stress tests with bicycle ergometer and their exercise performances were evaluated by means of the workload they achieved. Twenty eight of them were waiting for surgical therapy at the time of study and 55 were outpatients who had undertaken valvular surgery. They were from 13 to 68 years old (mean 49.3 years). Fifty three patients were male and 30 were female. Thirty six of them were in the state of NYHA functional classification class 1, 35 class 2 and 12 class 3. Workloads and oxygen uptake were measured at anaerobic threshold (AT) and maximal achieved workload (MAX). Measured values of workloads were assessed by the percent attainments of predicted normal values for age, sex, height and weight from the equation which were calculated from the data of 213 sedentary normal Japanese adults. Oxygen uptake was also assessed by the percent attainment of predicted normal value from Posner's equation. Woakloads and oxygen uptake were corelated significantly (p<0.01) both at AT and MAX. Workloads differed significantly between the NYHA classes not only at AT but also at MAX (p<0.01, p<0.01). Ten patients were reassessed more than six months after the operation and revealed significant increases in workload. The differences were more prominent at MAX than at AT.

A 34-year-old male with chest pain and shock was admitted as an emergency case to our unit. Ruptured acute aortic dissection with annuloaorticectasia was suspected and emergency operation was performed. Acute aortic dissection was localized at the aortic root. The right coronary orifice was involved with the dissection, and an intimal tear was found just above it. Aortic root replacement with composite graft was performed as follows. The aortic wall around the coronary orifice was incised in a circular manner like a button and the dissection of the aorta around the coronary orifice was repaired. Dacron tubes with xenopericardial skirts were interposed between the coronary orifices and the composite graft. Wrapping of the composite graft was completed using the aortic wall and xenopericardium. The postoperative course was uneventful with only slight bleeding. Our procedure is useful for acute aortic dissection around the coronary orifice.

A Successful surgical repair of a ruptured ventricular septum concomitant with a left ventricular free wall rupture secondary to myocardial infarction was performed on a 81-year-old woman. Anterior myocardial infarction was accompanied with a ventricular septal rupture, 7mm in size, and hemorrhagic dissection type left ventricular free wall rupture. Acute ventricular aneurysm formation of the left ventricle was also noticed. A review of the literature reveals that in surgical cases, the hemorrhagic dissection type ventricular rupture in left ventricle was usually concomitant with ventricular septal rupture.

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.

Various types of surgical techniques have been reported for the closure of complicated PDA, since Morrow first described an innovatory operative method. At our institute, extracorporeal circulation has been frequently used as a support measure for these operations to ensure the safety of the operation. Ten patients with complicated PDA were operated under extracorporeal circulation. All patients but one were adults. The reason for use of extracorporeal circulation included age, presence of atherosclerosis or calcification of the ductus, short neck ductus, ductal aneurysms, right sided descending aorta and recanalization after previous ligation. The ductus was approached through the left lateral thoracotomy in 8 patients and median sternotomy in 2. The Morrow procedure was performed in 2 patients. No hospital death occurred, although the mean duration of the hospital stay after the operation was longer in these cases than in cases with simple PDA. We conclude that the use of extracorporeal circulation is safe and effective for the closure of complicated PDA.