The stump pressure of the inferior mesenteric artery (IMA) was measured before and after aortic cross clamping during infra-renal abdominal aortic aneurysmal surgery in 50 cases. We analyzed the hemodynamics in IMA-supplied areas, and established an appropriate index to indicate intestinal ischemia. The IMA stump pressure after aortic cross clamping decreased significantly (p<0.0001), by 11% on an average. This means that the collateral blood supply from the internal iliac artery (IIA) is 11% of the total pressure and the collateral blood supply from the superior mesenteric artery (SMA) is 89%, therefore the SMA supply dominates that of the IMA. Intestinal ileus due to ischemia occurred in one patient who had the highest rate of pressure decrease after aortic cross clamping. The cause of ileus might be poor collateral blood supply from SMA and insufficient IIA blood flow preservation. The IMA stump pressure might be an index to predict intestinal ischemia. We analyzed the IMA stump pressure in 38 cases without IMA reconstruction who had no ischemia. The ratio of 0.6 in IMA stump pressure versus systemic pressure could be a safe index suggesting sufficient blood flow in IMA-supplied areas. IMA reconstruction and IIA preservation should be performed to maintain an IMA stump pressure ratio of 0.6.

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.

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.

Prosthetic graft replacement for thoraco-abdominal aneurysm was performed in a 69-year-old man. Fever and CRP elevation developed 8 days after the operation. A subcutaneous abscess was found in the wound. The culture of pus and thoracic discharge revealed methicillin-resistant staphylococcus aureus (MRSA). Infected tissues were debrided and an omentopexy was performed without removing the prosthetic graft to avoid spinal cord ischemia. The thoracic cavity was irrigated continuously with 1% Povidone-iodine for three days. The infection subsided gradually and the patient was discharged. Graft infection due to MRSA has recently increased and we experienced such a case which we treated successfully by complete debridement, omentopexy and continuous irrigation.

This report describes the results of endovascular stent graft repair for abdominal aortic aneurysms in comparison with conventional open surgery. Endovascular repair of abdominal aortic aneurysm was performed in 21 patients (SG group) and 69 patients were treated with conventional open surgery (OS group). The SG group had a higher preoperative risk than the OS group. The complete exclusion of the aneurysm at 2 weeks after the stent graft treatment was obtained in 16 out of 21 SG cases (76%). On the other hand, in the OS group, 68 of 69 cases underwent successful surgery (99%). The average amount of bleeding during the endovascular stent graft repair was 427ml and the average operation time was 242 minutes. Both blood loss and operation time were significantly lower compared to the OS group. The endovascular stent graft repair was less invasive in comparison with conventional open surgery. However, judging from the initial success rate, open surgery is more reliable than the endovascular stent graft repair. Our data suggested that the endovascular stent graft repair should be performed only in selected cases.

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.

We studied the appearance of pleural effusion and inflammatory reactions after endovascular grafting in cases of aortic dissection. From December 1995 to January 2000, 16 patients with chronic double-barrel type aortic dissection (DeBakey type III b) were treated by endovascular grafting. In all cases, enhanced computed tomography (CT) of the chest was examined before operation and at about the 7th postoperative day (POD). Patients were divided into 3 groups. Group P: patients who had pleural effusion before the operation. Group E: patients who had new pleural effusion after the operation. Group N: patients who did not have any pleural effusion. In each group, onset of dissection, patient's age, maximum diameter of dissecting aorta, period of postoperative fever (above 37.0°C), and WBC counts and CRP value at POD 1, 3, 7 and 14 were compared. Four patients were in group P, 4 patients were in group F, and 8 patients were in group N. Period between onset and operation was 41.6±34.6 months in group P, 18.2±27.3 months in group E and 7.3±11.6 months in group N. There was no relation between the effusion and the period after onset. Postoperative fever continued for 5.0±2.0 days in group P, 13.5±2.6 days in group E and 2.5±0.3 days in group N. The period of fever of group E was significantly longer than in group N and P (p<0.01). WBC showed a peak on the first POD in each group. CRP showed a peak value on POD 3 in group P and N. There was no significance among the 3 groups about WBC and CRP, but group E showed slightly high CRP values on POD 7 and 14. No patient had complications regarding respiratory function. After endovascular grafting for aortic dissection, postoperative pleural effusion appeared in 25% of patients. They had prolonged postoperative fever, but there was no respiratory function complication. Endovascular grafting is a minimally invasive procedure with regard to respiratory function.

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.

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.

To assess coronary artery disease in arteriosclerosis obliterans (ASO), the efficacy of a dipyridamole-loaded ECG was evaluated. Subjects consisted of 35 patients who underwent surgery for ASO between November 1988 and December 1989. A dose of 0.568mg/kg of dipyridamole was intravenously infused for over 4min. Changes of systemic blood pressure, heart rate and standard 12-lead ECG were accumulated. In eleven cases loaded ECG was considered to be positive and coronary arteriographies were performed. Stenotic lesions of 75% or over were observed in 10 cases, among them CABG was performed in one symptomatic case. In another positive but asymptomatic cases, only the existing ASO lesions were surgically treated. No intraoperative or postoperative ECG abnormality was observed and postoperative courses were uneventful. Negative cases (24 cases) underwent complete revascularization. These findings indicate that a dipyridamole-loaded ECG is a non-invasive preoperative means detecting coronary artery disease preoperatively is useful to decide operative procedure.