Long-term fate of aortic branches in patients with aortic dissection

Abstract

Objective: Late morbidity and mortality related to aortic branches in patients with aortic dissection (AD) have not been well described. We investigated the fate of aortic branches in a population cohort of patients with newly diagnosed AD.

Methods: We used the Rochester Epidemiology Project record linkage system to identify all Olmsted County, Minnesota, residents with a diagnosis of AD from 1995 to 2015. Only patients with >30 days of available follow-up imaging studies were included in the present analysis. The primary outcome was freedom from any branch-related event (any intervention, aneurysm, malperfusion, rupture, or death occurring after the acute phase >14 days). The secondary outcome was the diameter change in the aortic branches. Univariate and multivariable Cox proportional hazards models were used to identify the predictors of branch-related events. Univariate and multivariate linear regression models were used to assess the aortic branch growth rate.

Results: Of 77 total incident AD cases, 58 patients who had survived and had imaging follow-up studies available were included, 28 (48%) with type A and 30 (52%) with type B AD. The presentation was acute in 39 patients (67%), 6 (10%) of whom had had branch malperfusion. Of 177 aortic branches involved by the AD, 81 (46%) had arisen from the true lumen, 33 (19%) from the false lumen, and 63 (36%) from both. After the acute phase, freedom from any branch-related event at 15 years was 48% (95% confidence interval [CI], 32%-70%). A total of 31 branch-related events had occurred in 19 patients within 15 years, including 12 interventions (76% freedom; 95% CI, 63%-92%), 10 aneurysms (67% freedom; 95% CI, 50%-90%), 8 cases of malperfusion (76% freedom; 95% CI, 61%-94%), and 1 rupture (94% freedom; 95% CI, 84%-100%). No branch-related deaths had occurred. Type B AD (hazard ratio [HR], 3.5; 95% CI, 1.1-10.8; P = .033), patency of the aortic false lumen (HR, 6.8; 95% CI, 1.1-42.2; P = .038), and malperfusion syndrome at presentation (HR, 6.0; 95% CI, 1.3-28.6; P = .023) were predictors of late aortic branch-related events. The overall growth rate of aortic branches was 1.3 ± 3.0 mm annually. Patency of the aortic false lumen, initial branch diameter, and Marfan syndrome were significantly associated with diameter increase.

Conclusions: In patients with AD, aortic branch involvement was responsible for significant long-term morbidity, without any related mortality. Type B AD, patency of the aortic false lumen, and malperfusion syndrome at presentation resulted in a greater risk of branch events during the long-term follow-up. Dilatation of the aortic branches was observed in one third of cases during follow-up, especially in the case of a patent aortic false lumen or the presence of Marfan syndrome.

Keywords: Aneurysm; Dissecting aneurysm; False lumen; Ischemia; Malperfusion; Rupture.