The impact of true lumen morphology on frozen elephant trunk technique in chronic aortic dissection.

BACKGROUND

The frozen elephant trunk (FET) technique is widely used for treating extensive thoracic aortic diseases, including chronic aortic dissection (CAD). By combining open surgery with endovascular repair, it potentially improves true lumen (TL) blood flow and excludes distal arch intimal tears. However, long-term outcomes and complications such as stent graft-induced new entry (SINE) remain concerning. This study aims to evaluate the impact of TL morphology on the outcomes of the FET technique in CAD patients.

METHODS

Between 2014 and 2022, 23 patients with CAD underwent the FET procedure using the Frozenix prosthesis at our institution. Patients with degenerative aneurysms and acute dissections were excluded. The cohort included patients with chronic type B aortic dissection (48%), residual dissection after type A repair (30%), and chronic type A aortic dissection (22%). The mean age was 62.3 years, and 47.8% were male. TL morphology was classified based on computed tomography (CT) images as medial or lateral type, and as flat or circular. Postoperative outcomes, including the occurrence of SINE and the need for reinterventions, were analyzed in relation to TL morphology.

RESULTS

In-hospital mortality was 4.3% (n=1). Spinal cord injury occurred in 13% of patients. SINE was observed in 14% of patients (n=3), all associated with medial-type TL morphology (P=0.078). Patients with medial-type TL morphology had significantly higher rates of SINE and reintervention compared to those with lateral-type TL morphology. Freedom from reintervention at 5 years was significantly lower in the medial-type group (15%) compared to the lateral-type group (89%) (P=0.006).

CONCLUSIONS

TL morphology significantly impacts the outcomes of the FET procedure in patients with CAD. Medial-type TL morphology is associated with higher rates of SINE and reinterventions. Preoperative assessment of TL morphology is crucial for surgical planning, as tailoring the FET procedure to specific TL characteristics holds the potential to prevent complications and improve long-term outcomes in CAD patients.