The Long-Term Fate of Aortic Branches in Patients with Aortic Dissection

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.