Changes of stent-graft orientation after frozen elephant trunk treatment in aortic dissection

Objectives: Our goal was to evaluate the extent of stent-graft (SG) elastic recoil in the descending aorta after the frozen elephant trunk procedure in acute (AAD) and chronic (CAD) aortic dissection as well as the impact of SG movement on distal stent graft-induced new entry (d-SINE).

Methods: We retrospectively analysed 149 (105 AAD, 44 CAD) of 259 aortic dissection patients after the frozen elephant trunk procedure between January 2005 and April 2019. Inclusion criteria were at least 1-year computed tomography angiography (CTA) aortic examinations during a follow-up time of 3.8 ± 2.7 years and absence of open or endovascular reintervention. Multiplanar reconstruction of CTA scans was used to define the SG vector position and movement in a virtual Cartesian coordinate system. The angle φ of vector movement and changes of aortic areas at the distal landing zone were analysed.

Results: The distal SG position changed over time in the cranial (10.06 ± 11.12 mm), dorsal (8.45 ± 11.12 mm) and lateral (4.96 ± 9.89 mm) directions (P < 0.001). The total change of φ (4.08 ± 7.03°) was greater in AAD than in CAD (P = 0.026). d-SINE was more common in CAD (P < 0.001) and was associated with the size of the aortic area, aortic area enlargement and continuous SG unfolding (P < 0.001).

Conclusions: With the frozen elephant trunk technique, movement and change of SG orientation in the descending aorta were observed over time. Elastic recoil was greater in AAD than in CAD. The incidence of d-SINE was particularly dependent on the size of the aortic lumen and SG radial expansion and less on elastic recoil.