Midterm outcomes of endovascular repair for Stanford type B aortic dissection with aberrant right subclavian artery

Clinical question
Is complete endovascular repair durable for Type B aortic dissections with aberrant right subclavian artery?

Take away point
Complete endovascular therapy for Type B aortic dissection with aberrant right subclavian artery is a feasible, durable option with positive early- and mid-term outcomes.

Reference
Midterm outcomes of endovascular repair for Stanford type B aortic dissection with aberrant right subclavian artery. Zhang et al. JVIR. 2019;30:1378-1385.

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Study design
Single institution, single arm retrospective cohort study of 15 patients. 

Funding source
China Medical Board Distinguished Professorship Award and the National Natural Science Foundations of China

Setting
Second Xiangya Hospital, Central South University, Hunan, People’s Republic of China 

Summary 

A treatment algorithm for patients with Stanford Type B aortic dissection with the aberrant right subclavian artery (ARSA) was created based on the distance between the entry tear to the ARSA. If the distance was >15 mm (Type 1), TEVAR would be performed without any technical modifications owing to a favorable proximal landing zone. If the distance was <15 mm but >15 mm existed between the tear and the left subclavian artery (Type 2), the artery supplying the dominant vertebral artery was preserved while the contralateral artery was sacrificed. If <15 mm existed between the tear and left subclavian artery (Type 3), the artery supplying the dominant vertebral artery was preserved while the contralateral artery was sacrificed. In patients with codominant vertebral arteries, the ARSA was preserved in Type 2 patients while both subclavian arteries were preserved in Type 3 patients.

Technical modifications to TEVAR included fenestration for patients with an entry tear on the inner curve of the aorta, chimney (stent-graft preservation dependent on antegrade flow) for preservation of the left subclavian artery from left brachial approach, and periscope/snorkel (stent-graft preservation dependent on retrograde flow) for preservation of the ARSA from femoral approach.

Stent-grafts were oversized to account for concomitant diverticulum of Kommerell to cover the diverticulum without additional embolization of the diverticulum.

Follow-up included clinic visit and CTA at 2 weeks, 3 months, 6 months, and 12 months post-procedure. Mean follow-up was 33 +/- 20 months. There was 100% technical success. No mortalities were noted. No neurologic sequelae were noted. All stent-grafts remained patent with shrinking of the false lumen at 2 weeks.

Commentary

Although this paper is a small series from a single institution, the authors included a relatively high number of patients considering the rarity of this anatomy, which had previously only been described in case reports. Notably, the outcome for this cohort was remarkable with no delayed endoleaks and no clinically significant adverse events. Even with 13 patients undergoing chimney modification for preservation of the left subclavian artery, no delayed Type 1A endoleaks were identified. Whether this can be attributed to the wide variation in the duration of follow-up should be further investigated, since three patients with dominant left vertebral artery had less than 8 months of follow-up.

In the short- and mid-term outcomes of completely endovascular repair appear superior compared to outcomes of hybrid approach, with rates of brachial plexus injury of 12.5% and Type 1A endoleak of 18.8%. This study shows promise for completely endovascular repair although longer-term follow up is needed.

This paper also expands on previously published treatment algorithms for endovascular repair of aortic anatomy in a technically challenging population.


Post Authors 
Eric King, MD
Vascular & Interventional Radiology Fellow
Rush University Medical Center
Chicago, Illinois
@ercking

Sreekumar Madassery, MD
Assistant Professor, Vascular & Interventional Radiology
Director, Advanced Vascular & Interventional Radiology Fellowship
Rush University Medical Center
Rush Oak Park Hospital
Chicago, Illinois
@kmadass, vir_rush