[Surgical treatment of thrombosed aortic dissection].

We have performed the graft replacement of descending thoracic aorta for 6 patients with aortic dissection having non-opacified false channel on their initial CT and aortography from April 1990 to January 1993. We report the findings obtained from preoperative CT and aortographic findings and from operation with these patients. We also report the microscopic study of aortic wall resected at operation. In all the six patients were found by CT and angiography performed at the admission non-opacified false channel. In one patient, a re-dissection occurred at the mid-descending aorta four weeks later and extended into the abdominal aorta. Intimal tears were found during operation both at distal to the left subclavian artery and at mid-descending aorta in this patient, and microscopically the outer media of aortic wall had been ruptured and the advential scarring were more conspicuous than usual. In the other 5 patients, the local opacification was gradually increased in size during the follow up period. The site of local opacification was at the distal to the left subclavian artery in 3 and at the mid-descending aorta in 2. The operation for these patients revealed the existence of intimal tear at the involved aorta but the false channel had been closed. Microscopically, the involved aorta formed pseudoaneurysm and false channel had been closed with the organized thrombus. From these findings we conclude that surgical treatment should be considered for the aortic dissection when re-dissection occurred or local opacification was increased in size during follow up period, even if initial CT and aortography showed non-opacified false channel.