Aortic morphology and fenestration-related leak in fenestrated frozen elephant trunk: A cohort study

Objective anatomical criteria for selective fixation of the fenestration after fenestrated frozen elephant trunk (FET) are lacking. We examined the association between preoperative aortic morphology and fenestration-related leak.

We retrospectively analysed 44 consecutive patients with aortic dissection who underwent fenestrated FET during total arch replacement between 2021 and 2025. True aneurysms were excluded. Preoperative computed tomography (CT) was used to assess aortic short-axis diameter and true lumen (TL) morphology at three levels spanning the left subclavian artery origin. The outcome was fenestration-related leak, defined as persistent perigraft flow on the first postoperative contrast-enhanced CT scan before discharge. Comparisons used exact tests with Firth penalized logistic regression for adjusted associations.

Leak occurred in 12 patients (27.3%): 3 of 26 (11.5%) with fixation and 9 of 18 (50.0%) without (P = 0.007). Aortic diameter was larger in patients with leak (34.5 vs 29.9 mm; P = 0.002; area under the curve 0.80, 95% CI 0.63-0.97), and leak incidence rose across diameter strata (12.5%, 57.1%, 80.0%; exact trend P = 0.001). Flat TL morphology was more frequent with leak (P = 0.025); TL position was not associated. Diameter remained associated after penalized adjustment (odds ratio 1.29 per mm; P = 0.001); fixation was independently protective (odds ratio, 0.07; P = 0.002).

Fenestration-related leak was associated with larger preoperative aortic diameter and flat TL morphology, most evidently above 36 mm. Because fixation was chosen intraoperatively and few events occurred, these findings are exploratory and require prospective validation before they can be used to guide selective fixation.