Outcomes of Left Subclavian Artery Revascularization Strategies During Zone 2 Thoracic Endovascular Aortic Repair

Overview

Intentional coverage of left subclavian artery (LSA) is often necessary during thoracic endovascular aortic repair (TEVAR) to secure an adequate proximal landing zone. However, this may impair blood flow to vital vascular territories with increased risk of stroke, spinal cord ischemia and upper limb ischemia. Current recommendations from the Society for Vascular Surgery (SVS) and European Society for Vascular Surgery (ESVS) support the consideration of LSA revascularization in patients undergoing elective TEVAR with anticipated LSA coverage. In contrast, management in the acute setting is more complex and requires an individualized approach based on clinical urgency and anatomical factors. Revascularization is generally recommended in high-risk clinical scenarios, including patients with dominant left vertebral circulation, compromised or occluded contralateral vertebral artery, an incomplete circle of Willis, or variant vertebral anatomy such as a hypoplastic left vertebral artery terminating in the posterior inferior cerebellar artery or an isolated vertebral artery. Additional indications include prior LIMA grafting, the presence of upper limb dialysis access, anticipated extensive aortic coverage, or an aberrant right subclavian artery in which both subclavian origins may be compromised. Revascularization techniques encompass both open surgical and endovascular approaches. Surgical options include carotid-subclavian bypass, carotid-axillary bypass, and subclavian transposition, while endovascular methods involve branched or fenestrated endografts, chimney and periscope grafts, as well as in situ fenestration. Although surgical techniques provide durable long-term patency, they are associated with a risk of local complications. Endovascular approaches are minimally invasive; however, they may be associated with an increased risk of endoleaks. Anatomical factors also play a central role in determining both the feasibility and outcomes. Preoperative assessment using computed tomography angiography is essential to evaluate aortic arch morphology, proximal landing zone characteristics, branch vessel orientation, and access vessel suitability. In addition, the spatial relationship between the left common carotid artery (LCCA) and LSA, including minimum inter-vessel distances, directly influences the feasibility of branched or fenestrated endografts. Also branch vessel anatomy is equally critical, as LSA diameter, vertebral artery origin, and vessel length determine the suitability for branch incorporation or fenestration techniques. Furthermore, access-related anatomical constraints, particularly iliofemoral vessel diameter and calcification, may significantly limit device delivery.

Interventions

• Procedure Bypass graft
  Carotid subclavian bypass

Primary outcome measures

• Number of participants achieving technical success [Time frame: 30 days]
• Number of participants experiencing perioperative complications or requiring reintervention [Time frame: 30 days]

Secondary outcome measures (3)

• Number of participants with primary left subclavian artery patency at 3 years [Time frame: 3 years]
• Number of participants with assisted primary or secondary left subclavian artery patency [Time frame: 3 years]
• Number of participants requiring left subclavian artery reintervention [Time frame: 3 years]

Eligibility criteria

Inclusion criteria

Patients ≥18 years Undergoing TEVAR with proximal landing in zone 2 whether acute or chronic type B aortic dissection (TBAD), thoraco-abdominal aortic aneurysm (TAAA), penetrating aortic ulcer (PAU) or intramural hematoma (IMH).

• Treatment with one of the following:

• Single-branched stent grafts
• In-situ fenestration (e.g. ISLF ± stent)
• Chimney/periscope graft techniques
• Physician-modified endografts (PMEGs)
• Carotid-subclavian bypass, carotid-axillary bypass, or subclavian transposition

Exclusion criteria

• • Non revascularized left subclavian artery.

• Zone 0 or 1 procedures
• Multi-vessel arch debranching
• Blunt traumatic aortic injury (BTAI)
• Incomplete imaging or follow-up data

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Publications

• 1. Feezor RJ, Martin TD, Hess PJ, Klodell CT, Beaver TM, Huber TS, et al. Risk factors for perioperative stroke during thoracic endovascular aortic repairs (TEVAR). J Endovasc Ther. 2007 Aug;14(4):568-73. doi:10.1177/152660280701400420 PubMed PMID: 17696634. 2. Matsumura JS, Lee WA, Mitchell RS, Farber MA, Murad MH, Lumsden AB, et al. The Society for Vascular Surgery Practice Guidelines: managemen

Identifiers

NCT: NCT07697820 · TEVAR

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗