Ascending aorta-infrarenal abdominal aorta bypass was performed in 8 patients: 4 patients with dissecting aortic aneurysm, 3 patients with thoracic aneurysm and 1 patient with stenosis of the thoracic aorta after grafting for congenital thoracic aneurysm. Four patients who had aortic dissection underwent the thromboexclusion method, but thromboexclusion of the thoracic aorta occured in only one patient after additional clamp to the distal thoracic aorta. He is the only long-term survival in this series. The thromboexclusion method was also performed in two patients with infectious thoracic aortic aneurysm, but they died of aneurysmal rupture within 13 months after operation. One patient who undewent resection of a thoracic aneurysm with extra-anatomic bypass, developed respiratory insufficiency and paraplegia, and died of pneumonia. The patient with thoracic aortic stenosis is alive and well 11 years after operation. The indications of the thromboexclusion method for thoracic aneurysm should be limited only to very poor-risk patients who seem to be inaccessible to a direct approach. Ascending aorta-abdominal aorta bypass is recommended in cases of thoracic aortic stenosis.

To estimate the blood compatibility during extracorporeal circulation, we designed mock circulation system consisted of a membrane oxygenator and vinyl circuit with roller pump. Primed with 200ml Ringer's acetate and 200ml of fresh whole human blood, mock circulation was worked at flow rate 0.5l/min for 6hr. Heparin was not primed, oxygenator did not fill any gases and circulation was keeping at 37°C. The thrombin-antthrombin complex and fibrinopeptide-A showed progressive increase and fibrinogen correspondingly decrease. Nevertheless, the plasmin α2 plasmin inhibitor complex and D-dimer showed minimal changes within normal range in spite of increasing fibrinopeptide B β 15-42. We can not find any signs of secondary fibrinolytic activity. On the other hand, the platelet was persistently activated as shown statistically significant increase in β-thrombogloblin and platelet factor IV. Significant elevations of complement 3a and 4a were seen with increase of complement 5a and activated oxygen productivity by neutrophilic leucocytes. In conclusion, moderate and limited blood alterations occurred in mock cardiopulmonary bypass circuit.