Left Subclavian Artery Reconstruction With Laser-assisted Fenestration During the Procedure of Thoracic EndoVascular Aortic Repair for Type B Aortic Dissection
Phase: NA
Conditions: Type B Aortic Dissection
Sponsor: Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University

Cover page  
 
Official Title: LSA Reconstruction With Laser Fenestration During the TEVAR 
NCT number: NCT03845829 
Date of the document: November 1, 2020 
 
 

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Study Protocol 
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Objective This study aimed to prospectively evaluate the safety and efficacy of left 
subclavian artery (LSA) revascularization via in-situ laser-assisted fenestration 
during thoracic endovascular aortic repair (TEVAR) for type B aortic dissection 
(TBAD).  
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Design This was a prospective, single-arm, multicenter study that enrolled patients 
with complicated or high-risk acute TBAD. The LLTEVAR (LSA Revascularization 
With Laser-assisted Fenestration During TEVAR) study is a prospective, single-arm, 
multicenter trial that planned to enroll 100 patients at 5 vascular centers 
(NCT03845829). Patients presenting with complicated or high-risk acute TBAD with 
a proximal entry tear originating in zone 2 or zone 3, who were deemed 
appropriate candidates for TEVAR in conjunction with LSA revascularization, met the 
included criteria, and consented to participate were enrolled. The distance from the 
proximal edge of LSA orifice to the intended proximal landing location should 
be >5 mm. Patients were excluded if they were pre-procedurally scheduled to have 
proximal aortic arch coverage in zone 1 or zone 0. Other main exclusion criteria 
included patients who were inappropriate for TEVAR due to unfavorable anatomic 
characteristics (no commercially available aortic stent for the size of the aorta, no 
available access for TEVAR, both LAS and left vertebral artery originated from aorta, 
et al), previous open surgery for aortic arch and connective tissue disorders. The 
primary safety endpoint was freedom from composite major adverse events 
(mortality, stroke, myocardial infarction, rupture, paraplegia, type Ia endoleak) within 
30 days after the procedure. Univariate and multivariate analyses determined the 
risk factors of composite major adverse events. The primary efficacy endpoint was 
freedom from all-cause death, LSA in-stent restenosis, and reintervention due to 
dissection progression, growth, and endoleak at 1 year after the procedure.  
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Methods Once diagnosed, all patients received optimal medical therapy, 
consisting of close intensive care unit monitoring and control of blood pressure, 
heart rate, and pain. TEVAR procedures were performed for patients with 
complicated and high risk TBAD. Patients not responding to medical therapy or 
presenting with rupture or impending rupture, malperfusion were treated 
emergently; otherwise, TEVAR procedures were performed 2 weeks later. The 
procedure of TEVAR in adjunct with in-situ laser-assisted fenestration for LSA 
revascularization has been previously described in detail [19-21]. Briefly, the TEVAR 
procedures were performed under local or general anesthesia, and aortic stent-
grafts were deployed through femoral access, and the LSA fenestration stents were 
inserted through brachial artery. The diameter of the aortic stent-graft was based 
on the diameter of the proximal healthy landing zone of the aorta with 
approximately 5% oversizing. If the diameter of the stent-graft mismatched the 
diameter of the distal attachment site of the aorta (e.g, > 20% oversizing of the total 
aortic diameter), a distal restricted stent technique was used [24]. After aortic stent-
graft deployed, a 6F steerable sheath combined with a balloon catheter (Mustang, 
Boston Scientific, 4mm in diameter and 4cm in length) allowed the laser tip to be 
placed in the intended fenestration site outside of the aortic stent-graft. After the 

fenestration was established, the balloon catheter was pushed forward and through 
the fenestration hole, and after the balloon angioplasty for the established hole, the 
laser tip was exchanged with a 0.035-inch guidewire. Then the fenestration hole was 
subsequently dilated up to the reference diameter of the subclavian artery, and a 
balloon-expandable (Lifestream, BD) or self-expandable (Fluency, BD) covered-
stent (10% oversizing of the LSA in diameter) was deployed inside the fenestration. 
Post stent dilation was always required for the LSA stent. At the end of the 
procedure, arteriography was performed from the ascending aorta to assess the 
success of the procedure and to identify potential endoleak and residual stenosis of 
the LSA stent.  
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Statistical Analysis Plan (SAP): Con$nuous variables are presented as mean with 
standard devia$on, and categorical variables are summarized using counts and propor$on. 
Univariate logis$cs regression analysis was performed to determine the poten$al risk factors 
of major adverse events (mortality, stroke, myocardial infarc$on, rupture, paraplegia, type Ia 
endoleak, major bleeding, acute kidney injury, limb ischemia, bowel ischemia, retrograde 
dissec$on, stent-induced new entry (SINE), access site complica$ons and unplanned 
reinterven$ons), and only factors being found sta$s$cally signiﬁcant in the univariate analysis 
were included in the mul$variate analysis. The patency rate of LSA and the all cause related 
mortality were es$mated using the Kaplan-Meier method. SPSS version 26.0 (SPSS, Inc., 
Chicago, IL, USA) was used for the sta$s$cal analyses. Diﬀerences with a P value < 0.05 were 
considered sta$s$cally signiﬁcant.  
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Informed Consent Form (ICF): attachment 
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