Anatomic suitability for "off-the-shelf" thoracic single side-branched endograft in patients with type B aortic dissection.

Objective: Treatment of type B aortic dissections with thoracic endovascular aortic repair (TEVAR) has been adopted in many centers with the goal of covering the proximal entry tear. Coverage of the left subclavian artery (LSCA) is commonly required to achieve a dissection-free proximal seal zone. A novel thoracic single side-branched (TSSB) endograft device offers a potential off-the-shelf option to achieve total endovascular incorporation of LSCA during zone 2 TEVAR. The aim of this study was to determine what percentage of patients with type B aortic dissection who require zone 2 TEVAR meet the anatomical requirements for this device.

Methods: All consecutive patients undergoing TEVAR for type B aortic dissections at a single institution from 2006 to 2016 were evaluated. Three-dimensional centerline reconstruction of preoperative computed tomography angiography was performed to identify the diameter of the aorta, distances between branch vessels, diameter of the target branch vessel, and location of the primary entry tear. Only patients who met criteria for zone 2 TEVAR were included in the analysis. The primary outcome was percentage of patients that meet all anatomical requirements for TSSB. Individual criteria were evaluated independently, and results were stratified by dissection chronicity.

Results: Eighty-seven patients who underwent TEVAR for Stanford type B aortic dissections were reviewed. Fifty-seven (66%) would have required zone 2 TEVAR. Indications for TEVAR were malperfusion (12), aneurysm (15), persistent pain (22), rupture (3), uncontrolled hypertension (5), and other (3). Mean follow-up was 19 months (range, 1-72 months). Only 16 of the 57 patients (28%) met all the requirements for anatomic suitability. The primary contributor was that only 49% of patients had sufficient length between arch branches to prevent coverage of a proximal branch.

Conclusions: Although the new TSSB device can allow for a more proximal seal zone and eliminate the need for open aortic arch debranching, only 28% of patients with type B dissection who required zone 2 TEVAR met all the anatomic requirements for this device. Future devices will need to account for the short distance between the left carotid and LSCA to be more broadly applicable.