Optimal stent length and distal positioning of frozen elephant trunks deployed from the aortic zone 0 for type A acute aortic dissection

Objectives: To investigate the optimal stent length and distal positioning of frozen elephant trunks (FETs) in patients with type A acute aortic dissection (TAAD).

Methods: Between October 2014 and April 2021, 191 patients (FET-150 group: 37 patients; stent length, 150 mm; 66.3 ± 12.6 years and FET-non-150 group: 154 patients; 60, 90, or 120 mm; 64.1 ± 12.5 years) underwent total arch repair with FETs for TAAD using the "zone 0 arch repair" strategy. In the FET-150 group, the proximal stent end was positioned at the innominate artery origin of the arch. In the FET-non-150 group, the distal stent end was to be positioned just proximal to the aortic valve level using transesophageal echocardiography. The proximal end of the non-stented FET part was sutured to an arch graft together with the aortic wall at 1 to 2 cm proximal to the innominate artery origin.

Results: Distal stent ends were positioned at the thoracic vertebrae (Th) 4-5, 6-7, 8-9, and 10 levels in 0 (0%), 12 (32.4%), 25 (67.6%), and 0 (0%) patients, respectively, in the FET-150 group, and in 6 (3.9%), 98 (63.6%), 49 (31.8%), and 1 (0.7%), respectively, in the FET-non-150 group. No between-group difference in postoperative mortality was noted. The incidence of postoperative residual distal malperfusion and new-onset spinal cord ischemia in the FET-150 versus FET-non-150 groups were 2.7% versus 6.5% (P = .62) and 0% versus 1.9% (P = 1.00), respectively.

Conclusions: FET positioning with the distal stent end at around Th 8 can reduce residual distal malperfusion when a FET with a 150-mm stent is deployed from the aortic zone 0 in patients with TAAD undergoing total arch repair.