Improved Remodeling With TEVAR and Distal Bare-Metal Stent in Acute Complicated Type B Dissection

Background: The ASSIST (A multicentre Study in Survivors of type B aortic dissection undergoing Stenting) study compared both 1-year outcomes and evolution of true and false lumen (eg, remodeling) in patients with complicated type B aortic dissection subjected to thoracic endovascular aortic repair (TEVAR) with distal true lumen scaffolding by self-expanding nitinol open stent in comparison with TEVAR alone. Methods: The ASSIST study was a multicenter prospective single-arm study comparing clinical and imaging data from 39 consecutive patients (59.4 ± 13 years of age) who received TEVAR and the JOTEC E-XL open stent with data from matched control subjects treated with TEVAR alone based on 1:1 propensity score matching. Clinical data were collected by an independent Contract Research Organization (CRO) and computed tomography images were subjected to blinded core-lab analysis. Results: There were no differences in baseline demographics, clinical profiles, morphological data, procedural details, and in-hospital and 1-year outcomes between groups. Differences emerged with regard to evolution of both true lumen distal to stent graft, false lumen over the entire length of dissection, and remodeling (P <.001). At 1 year, TEVAR with the E-XL stent revealed false lumen thrombosis at the level of celiac trunk in 53.8% vs 17.9% with TEVAR alone (P =.004). Kaplan-Meier survival analysis indicated favorable clinical outcomes with the additional E-XL stent. Conclusions: TEVAR for acute complicated type B aortic dissection proved to be safe and promoted remodeling of the stent grafted thoracic aorta. Additional scaffolding of the true lumen distal to TEVAR with a self-expanding stent supported distal true lumen expansion, false lumen regression, and thrombosis, with evidence of improved distal remodeling at 1 year.