Long-term outcome and prognostic predictors of medically treated acute type B aortic dissections

Background. The purpose of this study was to examine the long-term outcome and the prognostic predictors related to the development of complications associated with acute type B aortic dissection. Methods. Seventy-six medically treated patients with acute type B aortic dissection were examined between 1990 and 2001. The events associated with aortic dissection included dissection-related death, rupture, visceral ischemia, lower limb ischemia, an increase in the maximum aortic diameter greater than 50 mm, and a mean enlargement rate of greater than 5 mm per year. Results. Among the 76 patients 10 (13%) underwent chronic phase surgery and 25 (33%) presented with an event. A statistically significant difference was observed between patients with and without events with regard to atherosclerotic factors, blood flow status in the false lumen, maximum aortic diameter upon admission, mean aortic enlargement rate, and blood pressure control during follow-up. Of these factors a patent false-lumen and a maximum aortic diameter greater than 40 mm upon admission were the most strongly associated factors with regard to the development of events. Patients with a patent false-lumen and a maximum aortic diameter greater than 40 mm upon admission were determined to exhibit significantly higher event rates than other patients. Conclusions. In determining the appropriate therapeutic approach for acute type B aortic dissection, it is important to pay careful attention to the predictors of a patent false-lumen and a maximum aortic diameter greater than 40 mm at onset to improve the long-term outcome. (C) 2004 by The Society of Thoracic Surgeons.