RESUMO
The authors studied 30 cases of aortic dissection performed from January 1978 to December 1987. Dissection was classified as type A (intimal tear beginning in the ascending aorta or arch) and type B (intimal tear beginning in the descending aorta). Type A predominated (66.7%). Type B dissection was most frequent in patients older than 60. Precordial pain was the main symptom in type A cases, whereas 62.5% of type B cases showed no precordial pain. Most frequent findings in type A patients were hypotension (45.5%), murmur of aortic regurgitation (40.0%), and dyspnea (40.0%), whereas in type B patients, most frequent findings were hypertension (28.6%), and pulse deficit (42.9%). The major differential diagnosis for type A was myocardial infarction (43.8%), and for type B, peripheral artery failure (25.0%) and acute pneumonia (25.0%). 24 patients (80.0%) had hemorrhage. Hemorrhage into the pericardial sac occurred in 68.8% of type A patients, and 50.0% of type B patients had retroperitoneal hemorrhage. Systemic hypertension, atherosclerosis, medial cystic necrosis and endocrine disorders were considered predisposing factors for both type of dissection. A case of dissection after aortic valve replacement associated with ascending aorta tubular graft replacement was observed in this series. In type A patients, average survival was 6.3 days, and in type B, 11.1 days. The major cause of death was hemorrhage (70.0%).