Morphology of the left subclavian artery: implications for single-branched endovascular aortic arch repair

Abstract

Abstract   OBJECTIVES Our goal was to evaluate the morphology of the aortic arch, focusing on the left subclavian artery (LSA), and to anticipate implications for single-branched endovascular aortic arch repair. METHODS We performed a morphological analysis of computed tomography angiography scans of 322 patients between January 2002 and December 2018. Arch type and distance between arch vessels on the convexity were evaluated. We defined 3 morphological types: U-type distance between the left common carotid artery (LCCA) and LSA offspring >10 mm; V-type distance between the LCCA and LSA offspring <10 mm and W-type isolated left vertebral artery offspring from the aortic arch. RESULTS Most patients presented a type III arch [50% (n = 161)]. The median distance from the brachiocephalic trunk offspring to the LCCA offspring measured 2.5 mm (2.0–3.0 mm) and that between the LCCA offspring and the LSA offspring was 6.5 mm (4.0–11.0 mm). We observed no significant difference based on the morphological type (V versus U versus W) in the brachiocephalic trunk–LCCA distance, but there were significant differences in the LCCA–LSA distance between types V and U (P < 0.001) and between types V and W (P < 0.001). Interestingly, we found no significant difference in the LCCA–LSA distance between types U and W. We noted a significant difference in the median diameter of the LSA according to U, V and W types: V type versus U type, 12.5 vs 13.5 mm (P = 0.033) as well as U type versus W type, 13.5 vs 10.5 mm (P < 0.001) and V type versus W type, 12.5 vs 10.5 mm (P < 0.002). The distances between the LSA offspring and left vertebral artery offspring between types U and V did not differ significantly. CONCLUSIONS Our categorization of the U, V and W types of the LSA can help us anticipate shapes and distances and thereby function as an initial evaluation tool for predicting single branched endovascular aortic arch repair involving the LSA.