Long-term follow-up of acute type B aortic dissection: ulcer-like projections in thrombosed false lumen play a role in late aortic events.

OBJECTIVE: Patients with Stanford type B dissection treated medically during the acute phase have a risk of surgery and aortic rupture during the chronic phase. We investigated the predictors for late aortic events by focusing on the false lumen status with computed tomography.
METHODS: A total of 160 patients were enrolled in the study, with a mean follow-up interval of 44.6 ± 25.4 months. Patients were divided into 3 groups according to the false lumen status at the time of onset: group T, thrombosed in 49 patients (30.6%); group U, thrombosed with ulcer-like projections in 52 patients (32.5%); and group P, patent in 59 patients (36.9%).
RESULTS: The mean aortic enlargement rate of groups U and P was greater than that of group T (0.40 ± 0.91 mm/month in group U, 0.44 ± 0.49 mm/month in group P, and -0.016 ± 0.23 mm/month in group T). The event-free rate in groups U and P was lower than in group T: 5-year event-free rates of 67.4% ± 8.2% in group U and 57.7% ± 10.9% in group P versus 95.0% ± 4.9% in group T (group T vs group U: P = .0011, group U vs group P: P = .96, group P vs group T: P = .0004). Cox regression analysis revealed that the false lumen status (patent or ulcer-like projections) (P = .029), maximum aortic diameter at onset (P < .0001), and patient age (P = .0069) were predictors of the late aortic events.
CONCLUSIONS: In type B aortic dissection, a thrombosed false lumen with ulcer-like projections and a patent false lumen had an influence on late aortic dilation and late aortic events.