Factors Affecting Compression of the Left Subclavian Artery Bridging Stent In Zone 2 Fenestrated Endovascular Arch Repair

Abstract

Introduction: Left subclavian artery (LSA) preservation during thoracic endovascular aortic repair (TEVAR) has been related to low morbidity. This study investigated the incidence of LSA stent compression in patients managed with fenestrated endovascular arch repair (f-Arch) and evaluated the impact of anatomic and technical factors on LSA stent outcomes. Methods: A single-center retrospective analysis of patients managed with single-fenestration devices (Cook Medical, Bloomington, IN, USA) for LSA preservation, between January 1, 2012 and November 30, 2023, was conducted. Anatomic (arch type, bovine arch, distance between the LSA and most proximal bone structure, left common carotid artery and aortic lesion, take-off angle, diameter, thrombus, calcification, dissection, tortuosity) and technical parameters (stent type, diameter, length, relining, post-dilation) were evaluated. Stent compression was any ≥50% stenosis (using center luminal line) of the stent compared with its initial diameter. Clinical outcomes included stroke and upper limb ischemia at 30 days and follow-up. Technical outcomes included stent compression and need for reintervention. Results: Fifty-four cases were included. Only balloon-expandable covered stents were used, and relining during the index procedure was performed in 18%. No stroke or arm ischemia was recorded. One stent compression was detected at 30 days. During follow-up, no stroke or arm ischemia was diagnosed. Nine cases (18%) presented stent compression, with a mean time of stent-compression diagnosis at 18 months (interquartile range [IQR]=37, range=1–58 months) after the index procedure. Five (56%) underwent secondary relining. Follow-up after reintervention was uneventful. Lower distance to the nearest bone structure (compression group [CG]: 11.7±8.9 mm vs non-compression group [NCG]: 23.0±7.8 mm, p=0.003) and higher tortuosity index (CG: 1.3±0.4 vs NCG: 1.2±0.1, p=0.03) were associated with LSA stent compression. Conclusion: LSA stent compression in patients managed with f-Arch affected 1 in 5 cases, without clinical consequences. Distance to the nearest bone structure and higher tortuosity were associated with LSA stent compression. Clinical Impact Fenestrated endovascular arch repair for the preservation of the left subclavian artery (LSA) in patients needing landing within the aortic arch has been performed with encouraging outcomes. This analysis showed that LSA stent compression is met in 18% of patients, without though any clinical consequence. Pre-operative anatomic parameters, as lower distance to the nearest bone structure and higher tortuosity index affect negatively LSA stent performance while stent parameters seem to have no impact.