[Natural history and prognosis of medical treatment for the patients with aortic dissections].

The natural history of patients with acute aortic dissections in extremely poor. In 1958, Hirst et al reported 21% of such patients died within a 24 hours, 80% died within a 4 weeks and 93% died with in a 1 year if not treated aggressively. However, there has been a dramatic improvement in the prognosis of patients with aortic dissections since the introduction of surgical treatment by DeBakey et al, and that of medical treatment by Wheat et al. We studied the long-term results of medical treatment for aortic dissections and evaluated the risk factors that determine the prognosis of medically treated patients. The survival rates of medically treated patients with type A dissections at 24 hours, 1 week, 1 month, 1 year, and 10 years after the onset of the disease were 74, 41, 36, 34, 23%, respectively, and the survival rates in type B dissections were 100, 94, 92, 85, 60%, respectively. The risk factors in the acute phase of dissections were type A and serious complications. These in the chronic phase were increasing age, the large diameter of the dissecting aorta and serious complications in acute phase, excluding shock and pericardial tamponade. These results show that emergency surgical intervention is indicated in the patients with acute type A dissections and in those who had acute type B dissections with serious complications.