Clinical outcomes of external fenestration TEVAR in Stanford type B aortic dissection involving the left subclavian artery: a retrospective study.

OBJECTIVE: This study assessed the clinical efficacy and hemodynamic effects of external fenestration thoracic endovascular aortic repair (TEVAR) in patients with type B aortic dissection (TBAD) involving the left subclavian artery (LSA). METHODS: A retrospective analysis of 110 patients who underwent this procedure between 2020 and 2024 was conducted, evaluating procedural success, complications, and follow-up outcomes. Hemodynamic changes were analyzed in 1 patient using computational fluid dynamics (CFD) based on pre- and postoperative CT angiography (CTA). RESULTS: Technical success was achieved in all cases. Complications included 3 cases of type I endoleak (2.7%), 1 type II endoleak (0.9%), 3 type IV endoleak (2.7%), 1 LSA stenosis (0.9%), and 2 deaths (1.8%). At a 5.7-month follow-up, 92.7% of patients showed complete false lumen thrombosis. There were occurrences of type I endoleak (2.7%), type II endoleak (1.8%), type IV endoleak (2.7%), LSA occlusion (2.7%), and LSA stenosis (2.7%). CFD analysis in the representative case demonstrated restoration of physiological flow patterns, including normalized streamlines in the LSA and stabilized wall shear stress in the stented segment. CONCLUSION: External fenestration TEVAR demonstrates favorable clinical outcomes and hemodynamic stability in TBAD involving the LSA, effectively promoting false lumen thrombosis and aortic remodeling while preserving LSA perfusion. Our findings suggest that complete entry coverage with an adequate proximal landing zone (≥15 mm when anatomically feasible) may be important for achieving false lumen depressurization, although this observation requires further validation. Further prospective studies are warranted to validate these findings.