Editor's Choice - Optimal Timing of Thoracic Endovascular Aortic Repair for Uncomplicated Type B Aortic Dissection: A Systematic Review and Meta-Analysis

Efficacy of intentional undersized thoracic endovascular repair for Stanford type B aortic dissection

OBJECTIVE

Thoracic endovascular aneurysm repair (TEVAR) is widely used for the treatment of aortic dissection. Endograft oversizing is a risk factor for stent graft-induced new entry tears and retrograde type A aortic dissection. However, there is no clear consensus on the optimal graft size selection for Stanford type B acute or subacute aortic dissection (TBAD). Herein, we examined the safety and efficacy of TEVAR using an intentionally undersized endograft to treat TBAD.

METHODS

This retrospective chart review study included 82 patients who underwent TEVAR for acute or subacute Stanford TBAD between 2015 and 2022. We measured the true lumen diameter just distal to the subclavian artery and opted for a stent graft of the same diameter. In instances where deformation resulting from false lumen pressure displacement was pronounced, we measured the diameter at the site just proximal to the subclavian artery. Patients' characteristics, procedural, in-hospital, and follow-up data, and aortic remodeling were analyzed. The aortic diameter was analyzed using one-way analysis of variance followed by Dunnett's test. Survival and freedom from reintervention were estimated using Kaplan-Meier curves.

RESULTS

The follow-up rate was 98.4%. The mean age was 58.3 ± 12.3 years, and 76 were men (92.7%). The mean diameters of the stent graft and native proximal landing zone were 30.9 ± 3.2 mm and 30.8 ± 3.0 mm, respectively. The oversize rate of the stent graft in relation to the native proximal aortic diameter was 0.3% ± 4.7%. In-hospital mortality was observed in one patient, retrograde type A aortic dissection in one patient, distal stent graft-induced new entry tear in zero patients, and type 1a endoleak in 22 patients (26.8%). Type 1a endoleaks, characterized by antegrade false lumen blood flow originating from the primary entry, in 12 patients spontaneously disappeared within 1 year of follow-up. According to aortic remodeling, 59 patients (86.8%) achieved complete aortic remodeling at the aortic arch level and 51 (75.0%) at the eighth thoracic vertebral level. The diameters of the aortic arch and descending aorta were significantly reduced compared with the postoperative measurements (P <.001). Survival rates were 97.5% and 93.6% at 1 and 3 years, respectively. Freedom from reintervention was 84.7% and 84.7% at 1 and 3 years, respectively.

CONCLUSIONS

Intentionally undersized TEVAR was safe and achieved acceptable aortic remodeling despite a high rate of type 1a endoleaks. A type 1a endoleak was acceptable as it primarily diminished during the mid-term follow-up.

A Chinese expert consensus on thoracic endovascular aortic repair of type B aortic dissection with a single-branched stent graft for revascularization of the left subclavian artery

Thoracic endovascular repair (TEVAR) is currently the recommended and most widely used treatment for type B aortic dissection. A major challenge is revascularization of the left subclavian artery in order to extend the landing zone to zone 2 (Ishimaru classification). Various strategies have been used for revascularization, including branched stent graft, fenestrated stent graft, the chimney technique, the parallel technique, and bypass surgery. Single-branched stent graft is one of the most promising strategies, and several products have recently been reported as potential candidates for use with this approach. The Castor single-branched stent graft is the only off-the-shelf product available; this product has been developed through collaboration between Chinese corporations and clinicians. In this Perspective article, clinical experience and data obtained from TEVAR with the Castor single-branched stent graft are summarized by experienced Chinese experts.