Patients with mechanical valve prosthesis must receive long-term oral anticoagulant therapy, thus it is important to set the optimal international normalized ratio of prothrombin time (PT-INR) that effectively prevented thromboembolic complications without excessive bleeding. In this study, anticoagulant therapy was evaluated in terms of the activity of coagulation and fibrinolysis in 137 patients after isolated mechanical valve replacement. With a lower target range of 1.5-2.0 for the PT-INR, thrombin antithrombin III complex (TAT) increased to more than 3.0ng/ml in 30 cases, and the activity of coagulation appeared to increase due to insufficient anticoagulant therapy. After the target range was raised to 2.0-2.5 in all cases, the PT-INR increased significantly from 1.63 to 2.25 (p<0.01) and TAT decreased significantly from 7.58 to 2.81ng/ml (p<0.01). This showed that activity of coagulation and fibrinolysis was suppressed by high intensity anticoagulation. It is necessary to review the individual activity of coagulation and fibrinolysis to determine the intensity of anticoagulation. We recommend 2.0-2.5 as the target range for the PT-INR.

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.

Coronary artery disease is common in patients with abdominal aortic aneurysm and arteriosclerosis obliterans, and one-stage or two-stage coronary artery bypass grafting have been performed. However, few operative cases of concomitant heart valve disease and arteriosclerotic disease have been reported. This case presented with severe aortic valve regurgitation (LVEF 24.3%) and arteriosclerosis obliterans (ASO) of both iliac arteries. To maintain the IABP catheter route and to prevent lower limb ischemia, aortic valve replacement with a bileaflet mechanical valve and abdominal aortic replacement with a bifurcated graft were carried out simultaneously. In spite of the high degree of operative invasiveness with median sternotomy and abdominal incision, the postoperative course was uneventful due to the shortened operation time and maintenance of good peripheral circulation.

The authors examined the frequency of thromboembolism and bleeding complications in cases of mechanical valve replacement during the past 5 years in the Tokyo area. There were 21 cases of thromboembolism and 15 cases of bleeding complications. Analyzing these cases with regard to anticoagulant therapy, 71% of the thromboembolism cases and 47% of the bleeding complication cases had 10∼25% result on the thrombotest at the time of the event. Consequently, in cases of mechanical valve replacement it is necessary to reevaluate the therapeutic range of the thrombotest results. This was a retrospective study of a TAS (The Tokyo area anticoagulation study for cardiac valve replacement by using PT-INR) trial and we intend to carry out a prospective study on the therapeutic range of the thrombotest and PT-INR.

A 58-year-old diabetic man underwent emergency coronary artery bypass grafting for ischemic heart failure. Although postoperative cardiac function was good but acute renal failure developed. We started continuous hemodiafiltration (CHDF) from 5 hours after the operation and continued it for 7 days without any undue influence on hemodynamics or bleeding side effects. The renal function gradually improved and CHDF was halted. It is reported that CHDF can prevent renal failure caused by inflammatory cytokines produced after cardiac surgery. CHDF appears to be useful for the management of acute renal failure in the early postoperative period after cardiac surgery.

We tried to identify the risk factors affecting the high mortality rates associated with ruptured abdominal aortic aneurysm (AAA). The subjects consisted of 18 patients, operated on for ruptured AAA, who were admitted to our hospital between 1992 and 1999. The preoperative factors, which were hemoglobin levels less than 9.0g/dl, creatinine levels higher than 2.1mg/dl, type 4 on the Fitzgerald classification, shock state lasting longer than 6h and a shock time index (the time from shock state onset to the beginning of operation divided by the time from complaint of abdominal pain to the beginning of operation) higher than 0.3, were associated with increased intraoperative and overall mortality rates. The postoperative factors, which were bleeding and blood transfusion more than 6, 000ml and an operating time of more than 400min, were associated with increased intraoperative and overall mortality rates. It is concluded that these risk factors were predictors of mortality and it is necessary to operate early because of the risk factors.

A 31-year-old man underwent mitral valve replacement because of mitral regurgitation due to continued active infective endocarditis despite antibiotic therapy. Because cerebral mycotic aneurysm was suggested by preoperative IVDSA (Intravenous Digital Subtraction Angiography), cerebral angiography was performed on the first postoperative day. Cerebral mycotic aneurysm was detected in the middle cerebral artery and emergency aneurysm trapping was successfully performed. Although the patient had no neurologic deficit and postoperative cardiac function was stable, impending rupture of the mycotic aneurysm of the superior mesenteric artery occurred suddenly on the twelfth postoperative day. Endovascular treatment using the coil-embolization technique was immediately performed, and the postoperative course was uneventful.