The procedure of cross clamping and declamping of the infra-renal abdominal aorta is common in the reconstructive abdominal aortic surgery. However, little is known to the oxygen free radical formations during the surgery. To evaluate the oxygen radical production, the malondialdehyde (MDA) levels in venous blood were measured prior to, during and after the operation with other metabolites such as C3, C3a, granulocytes, CPK, amylase, BUN, creatinine, beta-2-microglobulin, total protein (TP), hematocrit (Ht), GOT, GPT, LDH, lactate, potassium, and myoglobulin in ten patients of the infra-renal aortic aneurysm. The average of the aortic occlusion time was 63±18min in the patients. The levels of MDA (from 3.2±0.7nmol/ml to 2.3±0.5nmol/ml), C3, TP and Ht were decreased during the operation and there were significant correlations between the levels of MDA (r=0.486, p<0.01), C3 (r=0.59, p<0.01) and TP. It is, therefore, likely that the reduction of MDA and C3 levels is due to the blood dilution by the bleeding, fluid infusion and blood transfusion during the operation. The levels of C3a did not increase during and after the operation. The levels of CPK (from 73±40U/l to 920±705U/l) and amylase (from 183±87U/l to 444±420U/l) were temporary increased on the first day after the operation. The level of lactate was increased during the occlusion of the aorta (from 9.0±3.0mg/dl to 20.2±5.8mg/dl) and until the just after the operation (23.2±18.6mg/dl). The other metabolites such as GOT, GPT, BUN, creatinine and beta-2 microglobulin did not change throughout the investigation period. There was a substantial ischemia of lower extremities during the aortic occlusion resulted in significant increase of lactate level. These results suggest that the temporary occlusion of the infra-renal aorta during the common reconstructive abdominal aortic surgry does not produce the oxygen free radical formation which increases the lipidperoxidation level in the systemic circulation.

Eight patients with aneurysms in the ascending aorta and the aortic arch underwent reconstructive surgery under deep hypothermia and circulatory arrest between Jan., 1988 and Jun., 1991. The patients consisted of 3 males and 5 females, ranging in age from 45 to 73 years (62.0±11.8, mean ±S.D.). Four patients were operated on in emergency. The lesions in 7 of 8 patients were Stanford type A dissecting aneurysms and the remaining one was a true aneurysm in the ascending aorta and the proximal aortic arch. The operation time, extracorporeal circulation time, and circulatory arrest time were 432.6±147.3, 191.9±66.1, and 31.0±10.8 (16 to 47) min, respectively. In all cases, the ascending aorta and the proximal aortic arch were replaced by an artificial graft through the median sternotomy approach. The brachiocephalic artery was reconstructed in 2 cases. The intraoperative blood loss was 4, 685±2, 943ml and the blood transfusion was 4, 659±2, 779ml. All patients awoke from 2 to 19hr after surgery and no complication in the central nervous system was observed. The postoperative complications which were detected in 3 patients consisted of drug induced renal dysfunction in 1 case, sinus arrhythmia in another, and mild hepatic dysfunction in the last case. There were neither operative deaths nor late deaths during the follow up period which ranged from 1 month to 42 months. Deep hypothermia and circulatory arrest should be regarded as a good circulatory support technique in reconstrutive surgery of the ascending aorta and the proximal aortic arch.

A 67-year-old woman underwent simultaneous surgical treatment of aneurysms in the descending thoracic and abdominal aorta. The aneurysm in the descending thoracic aorta was 5.0cm in diameter. The abdominal lesion which was accompanied by closed partial dissection was located below the renal arteries and its diameter was 7.8cm. First, the patient was positioned in right decubitus position and left thoracotomy was made. The descending thoracic aorta was replaced with an artificial graft under partial cardiopulmonary bypass through the left femoral vein and artery. Thoracotomy was closed after removal of cardiopulmonary bypass and neutralization of heparin with protamine sulfate. The patient's position was then changed to supine, and following median laparotomy, her abdominal aorta was replaced with an artificial graft. Her postoperative course was entirely uneventful except for slight hoarseness and transient urine disorder. Although simultaneous operation for multiple aneurysms may give more surgical stress to patients, it can reduce the risk of rupture of the remaining aneurysm as compared with surgical treatment in two stages. The order in which aneurysms are operated on should be considered well in simultaneous operation. It was considered in this case that the thoracic lesion should be treated first because crossclamping of the abdominal aorta may increase cardiac afterloads and result in rise of intraluminal pressure and rupture of the thoracic aortic aneurysm.