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

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Aortic Aneurysm and Dissection
• Intervention / Treatment: Procedure: Bypass graft

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Surgery; Bypass	Procedure: Bypass graft; Carotid subclavian bypass
Active Comparator: Endovascular; Branched endograft	Procedure: Bypass graft; Carotid subclavian bypass

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants achieving technical success	Technical success is defined as successful stent graft deployment in the intended position with complete exclusion of the target aortic pathology, maintenance of left subclavian artery patency, absence of type I or III endoleak on completion angiography, and no intraoperative major adverse events (stroke, aortic rupture, or death). Results will be reported as the number and percentage of participants achieving technical success.	30 days
Number of participants experiencing perioperative complications or requiring reintervention	Perioperative outcomes include stroke, spinal cord ischemia, upper limb ischemia, myocardial infarction, access-related complications, aortic rupture, death, endoleak requiring treatment, and any unplanned surgical or endovascular reintervention occurring within 30 days after TEVAR. Results will be reported as the number and percentage of participants experiencing one or more events.	30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with primary left subclavian artery patency at 3 years	Primary left subclavian artery patency is defined as uninterrupted patency of the left subclavian artery without any surgical or endovascular reintervention during the 3-year follow-up period. Patency will be assessed by computed tomography angiography (CTA) or duplex ultrasound. The outcome will be reported as the number and percentage of participants with primary left subclavian artery patency.	3 years
Number of participants with assisted primary or secondary left subclavian artery patency	Assisted primary patency is defined as maintained LSA patency after an intervention performed before occlusion, while secondary patency is defined as restoration of flow after occlusion. Patency will be assessed by CTA or duplex ultrasound. Results will be reported as the number and percentage of participants maintaining assisted primary or secondary patency.	3 years
Number of participants requiring left subclavian artery reintervention	LSA-related reintervention includes any surgical or endovascular procedure performed to maintain assisted primary patency or restore secondary patency, including angioplasty, stenting, thrombectomy, bypass revision, or redo bypass. Results will be reported as the number and percentage of participants requiring one or more reinterventions.	3 years

Collaborators and Investigators

• Sponsor: Assiut University

Publications and helpful links

General 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: management of the left subclavian artery with thoracic endovascular aortic repair. J Vasc Surg. 2009 Nov;50(5):1155-8. doi:10.1016/J.JVS.2009.08.090 PubMed PMID: 19878791. 3. Wanhainen A, Gombert A, Antoniou GA, Fidalgo Domingos LA, Gouveia e Melo R, Grabenwöger M, et al. European Society for Vascular Surgery (ESVS) 2026 Clinical Practice Guidelines on the Management of Descending Thoracic and Thoraco-Abdominal Aortic Diseases. European Journal of Vascular and Endovascular Surgery. 2025 Feb 1;71(2):172-270. doi:10.1016/J.EJVS.2025.12.050/ATTACHMENT/4919EBC3-7A5C-48FD-9138-D4C9AB08CE0D/MMC3.PDF PubMed PMID: 41448425. 4. Upchurch GR, Escobar GA, Azizzadeh A, Beck AW, Conrad MF, Matsumura JS, et al. Society for Vascular Surgery clinical practice guidelines of thoracic endovascular aortic repair for descending thoracic aortic aneurysms. J Vasc Surg. 2021 Jan 1;73(1):55S-83S. doi:10.1016/J.JVS.2020.05.076/ASSET/A831C192-C4DD-4DCB-9701-3DD23F180CA0/MAIN.ASSETS/GR2.JPG PubMed PMID: 32628988. 5. Lin F, He Z, Gao J, Huang X, Wang H, Han L, et al. Comparison of surgical and endovascular left subclavian artery revascularization during thoracic aortic endovascular repair: a systematic review and meta-analysis. Front Cardiovasc Med. 2023 Nov 2;10:1274629. doi:10.3389/FCVM.2023.1274629/TEXT 6. Scali ST, Chang CK, Pape SG, Feezor RJ, Berceli SA, Huber TS, et al. Subclavian revascularization in the age of thoracic endovascular aortic repair and comparison of outcomes in patients with occlusive disease. J Vasc Surg. 2013 Oct;58(4):901-9. doi:10.1016/J.JVS.2013.04.005 PubMed PMID: 23711694.

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): October 1, 2028
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: June 24, 2026
• First Submitted That Met QC Criteria: July 10, 2026
• First Posted (Actual): July 13, 2026

Study Record Updates

• Last Update Posted (Actual): July 13, 2026
• Last Update Submitted That Met QC Criteria: July 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Dissection, Blood Vessel; Acute Aortic Syndrome; Vascular Diseases; Cardiovascular Diseases; Aortic Diseases; Aneurysm; Aortic Dissection
• Other Study ID Numbers: TEVAR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No