Abstract

Objective: In order to prevent complications and rupture, we determined the indications for surgical treatment of acute type B aortic dissection before the aortic diameter became enlarged, by studying patients with chronic-phase enlargement of aortic dissections

Methods: In 108 patients with type B dissection who had been treated medically during the acute phase, univariate and multivariate factor analyses were performed to determine the predominant predictors of chronic-phase enlargement (60 mm) of the dissected aorta. Computed tomography was performed every 6 to 18 months to observe whether enlargement of the maximum aortic diameter had occurred.

Results: A total of 58 patients subsequently underwent surgery for aortic enlargement in the chronic phase. The predominant predictors of enlargement in the chronic phase by univariate analysis were a patent false lumen (p < 0.001) and a maximum aortic diameter of 40 mm during the acute phase (p < 0.01). The only significant predictive variable of aortic enlargement by multivariate analysis was a patent false lumen (p < 0.01). The values of actuarial freedom from aortic enlargement for a closed false lumen at 1, 5, and 10 years were 96%, 92%, and 86%, respectively, whereas those for a patent false lumen were 54%, 36%, and 20%, respectively. The actuarial survival rates for a closed false lumen at 1, 5, and 10 years were 100%, 96%, and 96%, respectively, whereas those for a patent false lumen were 94%, 80%, and 64%, respectively.

Conclusion: These data suggest that patients with acute type B aortic dissection showing a patent false lumen should be treated surgically earlier in the chronic phase provided that the surgical risk in this phase is limited. Meanwhile patients with a closed false lumen can be treated medically as long as the aortic diameter does not become enlarged.