[Predictors of chronic aortic events associated with uncomplicated type B aortic dissection]

Stent-graft repair may emerge as a first-line therapy for acute complicated type B dissection(C-TBD), while debate continues over thoracic endovascular aortic repair (TEVAR) for uncomplicated type B aortic dissection (U-TBD). Aggressive medical therapy, which confers a 1-year survival rate of 80-90%, is deemed appropriate for most of these patients. However, it is reported that aortic complications occur in ≤ 50% patients within 5 years after surgery. Subgroups of patients with U-TBD may benefit from early stent-graft placement, but identification of these patients remains difficult. Therefore, we assessed the predictors of chronic aortic events associated with U-TBD.

Between January 2001 and April 2012, 49 patients diagnosed with communicating U-TBD without aneurysm formation were admitted to our hospital. These patients were divided into 2 groups:group AC (n=25) with chronic aortic complications (aneurysm formation, aortic diameter expansion of 5 mm/0.5 year, re-dissection, and rupture) and group NC (n=24)with no aortic complications. We assessed and compared patient profiles and imaging findings between the 2 groups.

Aortic diameter ≥ 40 mm was more often seen in group AC than in group NC (p=0.018). In addition, intimal tear in the distal arch was more often seen in group AC than in group NC ( p=0.002). Initial aortic diameter was significantly larger in group AC than in group NC (p=0.004). There was no significant difference in the length of communicating false lumen between the 2 groups ( p=0.107).

Early endovascular intervention may be appropriate for U-TBD in cases displaying an initial aortic diameter ≥ 40 mm and an initial tear in the distal arch. It is expected that randomized studies, including ADSOAB study (a study on the efficacy of endovascular grafting in uncomplicated acute dissection of the descending aorta.), will resolve the limitations of our retrospective study.