Aortic branch occlusion may constitute the mode of presentation or become an important focus of treatment in patients sustaining acute aortic dissection. We reviewed the outcome of 187 consecutive patients (149 males and 38 females, mean age 58 yrs) with acute dissection of the thoracic aorta who were admitted and operated in our clinic during a 13-year period. We assessed the incidence, the consequences and the specific management of stenotic and obstructive lesions of the aorta and its branches. Noncardiac vascular complications occurred in 59 patients (32%); out of these complications, 38 were associated with dissection type A (incidence 28%) and 21 with dissection type B (incidence 48%). Trend towards decreasing overall surgical mortality was observed in the second part (1983-1989) of the study when compared with the first part (1977-1982): it was 28% versus 12%. Although aortic rupture and cardiac tamponade were the strongest correlate of morbidity and mortality, death specifically related to vascular complication was more common when such malperfusion occurred in the carotid, coelio-mesenteric and renal circulation. Proximal aortic repair at the site of the intimal tear with obliteration of the false lumen may have restore adequate distal circulation in 27 patients in whom improvement of the visceral or peripheral ischemia was observed after the thoracic aortic repair. Additional procedures (immediately after the thoracic repair or later on) were necessary in 15 patients to restore adequate perfusion in the compromised area. Early aggressive thoracic aortic repair followed in selected patients by additive vascular procedures can save some patients with compromise visceral or peripheric circulation.(ABSTRACT TRUNCATED AT 250 WORDS)