Aortic remodeling after endovascular repair of acute complicated type B aortic dissection.

Objective: The role of thoracic endovascular aortic repair (TEVAR) in the management of acute type B aortic dissection remains undefined. Entry tear coverage during the acute phase is an appealing method to treat acute complications, and by inducing false lumen thrombosis, might also prevent late aneurysm formation. This study evaluated structural changes by serial computed tomography (CT) in the thoracic aorta after TEVAR performed for acute complicated aortic dissection.

Methods: Between August 2005 and October 2007, 33 patients with complicated acute type B aortic dissection were treated with TEVAR (19 from a prospective industry sponsored trial, 14 from our institution). CT images obtained preprocedurally (PP), at 1 month (1M), and 1 year (1Y) were evaluated for each patient. Four patients with no postprocedural imaging were excluded. The largest diameters of the thoracic aorta, dissection true lumen, and false lumen were recorded at each time point. Changes in total aortic and true and false lumen diameters were evaluated using a mixed effect analysis of variance model of repeated measures.

Results: The average age was 58 years (range, 38-87 years); 26 (81%) were male. Indications for TEVAR included malperfusion syndrome in 17 (53%), refractory hypertension in 14 (44%), impending rupture in 12 (28%), and refractory pain in 14 (44%); 19 (59%) had more than one indication. The average length of aorta covered was 19.5 cm (range, 10-29.3 cm). The maximum aortic diameter decreased over time (P = .04) and averaged 39.9 (PP), 41.3 (1M), and 34.8 mm (1Y). The true lumen diameter increased over time (P = .02) and averaged 23.7 (PP), 29.0 (1M), and 31.1 mm (1Y). The false lumen diameter decreased (P = .046) and averaged 19.5 (PP), 12.1 (1M), and 9.6 mm (1Y). Partial or complete thrombosis of the false lumen along the stented segment of aorta was recorded in 87% (PP), 93% (1M), and 88% (1Y).

Conclusions: TEVAR of acute complicated aortic dissection appears to promote early aortic remodeling. Nearly 90% of patients maintained at least partial false lumen thrombosis at 1 year. Because continued false lumen patency correlates strongly with late aneurysm formation, such favorable remodeling is considered a surrogate for prevention of late aneurysm, but longer follow-up is required.