Left Subclavian Artery Revascularization With In Situ Laser Fenestration During Thoracic Endovascular Aortic Repair for Acute Complicated or High‐Risk Type B Aortic Dissection: Results of the LLTEVAR Trial

Background Coverage of the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) increases the risk of major adverse events (MAEs). In situ laser‐assisted fenestration allows for LSA revascularization in both elective and urgent settings, yet its safety and efficacy lack robust multicenter data. Methods LLTEVAR (LSA Revascularization With Laser‐Assisted Fenestration During TEVAR) was a prospective, single‐arm, multicenter study that enrolled patients with acute complicated or high‐risk acute TBAD. The primary safety end point was freedom from composite MAEs (mortality, stroke, myocardial infarction, paraplegia, type Ia endoleak, and retrograde aortic dissection/intramural hematoma) within 30 days after the procedure. Univariate and multivariable analyses identified risk factors for composite MAEs. Results A total of 100 patients (mean age, 60.5±12.6 years) were enrolled at 5 vascular centers between July 2018 and September 2021. The technical success rate of LSA fenestration was 98.0% (98/100). The 30‐day primary safety end point was 86.0%. Complicated TBAD (OR, 4.04; 95% CI, 1.05–15.59; P =0.04) and type II/III aortic arch (OR, 4.61; 95% CI, 1.18–17.95; P =0.03) were significantly associated with a higher risk of composite MAEs within 30 days. Conclusion In situ laser‐assisted fenestration for LSA revascularization during TEVAR demonstrates favorable procedural success and acceptable short‐term outcomes in patients with acute TBAD. However, periprocedural MAEs remain a critical consideration, particularly in those with complicated TBAD with type II/III aortic arch anatomy. Further studies with comparative groups and long‐term follow‐up are warranted to validate these outcomes. Registration URL: https://clinicaltrials.gov ; Unique Identifier: NCT03845829.