Volume analysis of true and false lumens in acute complicated type B aortic dissections after thoracic endovascular aortic repair with stent grafts alone or with a composite device design

Abstract

Objective: This study compared the 12-month evolution of the aortic volume in patients who underwent thoracic endovascular aortic repair (TEVAR) with stent grafts alone or a composite device (Zenith TX2 stent graft and Zenith Dissection stent; Cook Medical, Bloomington, Ind) for acute (≤2 weeks from onset) complicated type B aortic dissection.

Methods: This was a retrospective analysis comparing prospectively collected data from 45 patients who underwent standard TEVAR repair at three European institutions (TEVAR group) and 39 patients in the Study of Thoracic Aortic type B Dissection using Endoluminal Repair (STABLE I) study who received a composite device (STABLE group). The analysis included consecutive patients treated for acute, complicated type B dissection and with available baseline and 12-month computed tomography imaging. Volume analysis was performed by using a semiautomated centerline algorithm.

Results: Baseline demographics, medical history, extent of dissection, and clinical indications were largely similar between the two groups. There was no difference in the length of aorta covered by stent grafts (167 ± 47 mm in STABLE and 184 ± 49 mm in TEVAR; P = .11). The STABLE group had an initial larger false lumen volume in the thoracic (203 ± 72 cm(3) vs 162 ± 74 cm(3); P = .01) and abdominal aorta (63 ± 29 cm(3) vs 36 ± 27 cm(3); P < .001). In the thoracic aorta, each group exhibited a significant increase in true lumen volume and a significant decrease in false lumen volume through 12 months. The total aortic volume increased significantly in the STABLE group (P < .001) but not in the TEVAR group. In the abdominal aorta, only the STABLE group exhibited a significant increase in the true lumen volume (P < .001) and a significant decrease in the false lumen volume (P = .004) postoperatively. At 12 months, the true lumen continued to increase significantly in the STABLE group (P = .03). However, no statistically significant difference was detected when the two groups were compared for the overall changes in the true lumen and false lumen volumes from preprocedure to 12 months, and both groups exhibited a statistically significant increase in total abdominal aortic volume at 12 months. There was no statistical difference between the two groups in the proportions of patients who experienced >10% changes in the thoracic or abdominal total lumen volume after TEVAR. Patients in the two groups (all survived 12 months) had similar clinical outcomes, including rupture, conversion, and reinterventions.

Conclusions: According to this volume analysis, thoracic endografting for acute complicated type B dissections promotes significant thoracic aortic remodeling. The use of bare-metal dissection stents leads to significant true lumen expansion and false lumen regression in the early follow-up and to subsequent continued true lumen expansion in the abdominal aorta; however, a definitive benefit in aortic remodeling over TEVAR alone was not demonstrated at 1 year.