Influence of Primary Intimal Tear Location in Type B Aortic Dissection as a Factor Portending Retrograde Type A Aortic Dissection after Endovascular Repair.

PURPOSE: To investigate the effect of a primary intimal tear's position on the distal convexity as a factor predisposing patients to developing a retrograde type A aortic dissection (RTAAD) after endovascular repair for type B aortic dissections.

MATERIALS AND METHODS: From January 2010 to December 2015, 334 patients with type B aortic dissections identified from a retrospective thoracic endovascular repair database were assigned to 2 groups based on the location of primary intimal tears in the distal aortic arch. Other potential risk factors were analyzed, and Kaplan-Meier survival curves were constructed.

RESULTS: The location of the primary intimal tear was identified in 230 patients (68.9%) in the convexity group and in 104 patients (31.1%) in the concavity group. After intervention, 20 patients (convexity: 7.8%, concavity: 1.9%) developed an RTAAD. Univariate analysis identified that the location of the primary intimal tears (P = .053), the areas involved by dissection (P = < .001), and the covering of the brachiocephalic trunk (P = .024) were significantly associated with RTAAD. Multivariate analysis revealed that a primary entry tear at the distal convexity might be a predictor for developing RTAAD (P = .053), with a relative risk of 4.243 (95% confidence interval, 0.984-18.286).

CONCLUSIONS: Patients with primary intimal tears located in the distal convexity may be more likely to develop RTAAD than patients with primary intimal tears in the distal concavity.