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 compl ications, better results are obtained if surgery is performed before enlarg ement 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-ph ase factors that may affect chronic-phase aortic enlargement by studying ch ronic-phase enlargement of dissections in patients without complications du ring the acute phase. Methods and Results-In 101 patients with type B acute dissection who had no complications, univariate and multivariate factor analyses were pel formed to determine the predictors for chronic-phase enlargement (greater than or equal to 60 mm) of the dissected aorta. The independent predominant predic tors for aortic enlargement in the chronic phase were a maximum aortic diam eter of greater than or equal to 40 mm and a patent false lumen during the acute phase. The values of actuarial freedom from aortic enlargement for th e patients with a maximum aortic diameter of greater than or equal to 40 mm and a patent false lumen at 1, 5, and 10 years were 43%, 33%, and 22%, res pectively, whereas in patients with a maximum aortic diameter of <40 mm and a closed false lumen, the values were 97%, 93%, and 84%, respectively. Conclusions-These results suggest that patients with type B acute aortic di ssection who show a maximum aortic diameter of greater than or equal to 40 mm and a patent false lumen should undergo surgery earlier during the chron ic phase before enlargement of aorta, whereas patients with a maximum aorti c diameter of <40 mm and a closed false lumen should continue to receive hy potensive therapy.