Toward the Best Treatment for Uncomplicated Patients With Type B Acute Aortic Dissection : A Consideration for Sound Surgical Indication

BACKGROUND: In the treatment of type B acute aortic dissection without complications, better results are obtained if surgery is performed before enlargement of the aorta in patients who are predicted to show aortic enlargement and if drug-based treatment is continued for patients who are predicted to show no enlargement. The purpose of this study was to predict the acute-phase factors that may affect chronic-phase aortic enlargement by studying chronic-phase enlargement of dissections in patients without complications during the acute phase. METHODS AND RESULTS: In 101 patients with type B acute dissection who had no complications, univariate and multivariate factor analyses were performed to determine the predictors for chronic-phase enlargement (>/=60 mm) of the dissected aorta. The independent predominant predictors for aortic enlargement in the chronic phase were a maximum aortic diameter of >/=40 mm and a patent false lumen during the acute phase. The values of actuarial freedom from aortic enlargement for the patients with a maximum aortic diameter of 40 mm and a patent false lumen at 1, 5, and 10 years were 43%, 33%, and 22%, respectively, whereas in patients with a maximum aortic diameter of <40 mm and a closed false lumen, the values were 97%, 94%, and 84%, respectively. CONCLUSIONS: These results suggest that patients with type B acute aortic dissection who show a maximum aortic diameter of >/=40 mm and a patent false lumen should undergo surgery earlier during the chronic phase before enlargement of aorta, whereas patients with a maximum aortic diameter of <40 mm and a closed false lumen should continue to receive hypotensive therapy.