The surgical experience in the treatment of 72 patients with proximal aortic dissections was analized to identify the determinants of high operative risk. Thirty-seven patients were operated upon in the acute stage and the dissection was restrict to ascending aorta in 9. The most common surgical procedure was the interposition of Dacron graft in the ascending aorta associated to obliteration of false lumen. The aortic arch was approached only in 5 patients. The overall operative mortality was 27.7% and patients with acute dissections had mortality rate of 43.5%. There was a direct relationship between the causes of death and preoperative complications in 45% of these cases. The following factors were considered predictors of high operative risk: previous neurologic compromise, cardiac tamponade, persistent shock, acute myocardial ischemia and renal dysfunction. Involvement of innominate or carotid arteries by dissection, presence of intimal tear in aortic arch, mesenteric ischemia and only in the acute cases, moderate or severe aortic valve incompetence were also correlated with a higher operative mortality. In conclusion, the operative risk of the treatment of proximal aortic dissection has a relationship with preoperative clinical condition. Better results in the acute stage could be improved by early diagnosis and adequate medical therapy during investigation period.
thoracic aorta; thoracic aorta