RS13 - Aortic Remodeling Following Thoracic Endovascular Aortic Repair Extension for Residual Type B Dissection in Patients with Previous Frozen Elephant Trunk

Objectives: Residual type B aortic dissection (TBAD) following Frozen Elephant Trunk (FET) can lead to aneurysmal degeneration and rupture. Aortic remodeling following thoracic endovascular aortic repair (TEVAR) extension in patients who had residual TBAD and previous FET has not been reported. The aim of this study is to gauge the impact of extension TEVAR on aortic remodeling in this patient cohort.

Methods: Data on patients with previous FET who underwent TEVAR extension from 2016 to 2022 were analyzed. Pre- and post-operative computed tomography angiography (CTA) were compared using centerline analysis. Positive and negative aortic remodeling and changes in total aortic and/or dissection lumen diameter > 5mm were considered significant.

Results: There were 40 patients with mean age of 58 +/- 15.6 at TEVAR procedure and 77.5% (31) were male. Median time from FET to TEVAR was 2 months (IQR 0-10.5), and 77.5% (31) patients had at least 1 follow-up CTA. Visceral segment dissection was present in 87.5% (35/40) (Table 1).

At the distal portion of the FET, 70% (21/30) of patients had positive aortic remodeling, 26.7% (8/30) had negative aortic remodeling, and 3.3% (1/30) had stable aortic measurements. At the level of T10, 45.2% (14/31) had positive aortic remodeling, 35.4% (11/31) had negative aortic remodeling and 19.4% (6/31) had stable measurements. At the level of the celiac artery, 43.3% (13/30) had stable measurements, 29.0% (9/30) had negative aortic remodeling, and 26.7% (8/30) had positive aortic remodeling (Fig 1).

Most dissections at T10 progressed to complete false lumen (FL) thrombosis (24/29, 82.8%). At the visceral plate, only 16% (4/25) had complete FL thrombosis, 52% (13/25) had partial thrombosis and 32% (8/25) had no thrombosis. At the infrarenal aorta, 57.1% (12/21) had no FL thrombosis, 28.6% (6/21) had partial thrombosis and only 14.3% (3/21) had complete FL thrombosis.

12 (30%) patients required complex abdominal aortic intervention either via open or endovascular repair due to progression of disease with negative remodeling. Thirty-day major adverse cardiovascular event rate was 10% and inpatient mortality was 5%.

Conclusions: TEVAR extension for residual TBAD in patients with previous FET is associated with more positive aortic remodeling and FL thrombosis above the level of the celiac artery, with decreasing remodeling effects distal to it. Morbidity and mortality rates are low; however, a third of patients with residual TBAD following FET and extension TEVAR develop negative aortic remodeling requiring additional interventions.