Abstract
OBJECTIVE: Different zone 0 endograft designs have been introduced. This study sought to assess postimplantation hemodynamic changes induced by zone 0 endografts, with varied configuration of side branches, using computational models. METHODS: Twenty-nine patients who underwent zone 0 endovascular repair with single-, double-, or triple-branched endografts (n = 7, n = 11, n = 11, respectively), using different configurations of antegrade (A) and retrograde (R) branches, were included. Computational simulations were used to assess postimplantation changes in peak flow rate, systolic blood pressure (SBP) and time-averaged wall shear stress (TAWSS) at the innominate artery (IA), right subclavian artery, right common carotid artery (CCA), left CCA (LCCA), left subclavian artery (LSA), and distal aortic arch, as well as the total displacement force (DF) of the endograft. RESULTS: Regardless of orientation, IA side branch implantation increased the IA peak flow rate across all endograft designs, an effect significant only in single-branched devices (+70%, P = .02). This increase was accompanied by a significant decrease in peak flow in the LCCA and LSA for single- (P = .02 and P = .02, respectively) and double-branched devices (P = .01 and P < .001, respectively), whereas no such effect was observed with triple-branched devices. Notably, the two antegrade branches supplying the IA and LCCA and one retrograde branch to the LSA- and three retrograde branches (3R)-triple-branched designs had the opposite effect on LCCA blood flow (+8.3% vs -6.7% [P = .02], respectively), although their impact on LSA flow did not differ significantly (-7.5% vs -8.1% [P = .92], respectively). This resulted in disparate effects on distal arch flow (-0.3% vs +6.3% [P = .02], respectively). Postimplantation alteration in distal arch flow was progressively attenuated with more branches. The preimplantation to postimplantation SBP differences in the IA, LCCA, and LSA mirrored the corresponding changes in peak flow. Elevated peak flow in the IAs led to a significant postimplantation increase in the TAWSS across all device designs. In contrast, the LSA side branches with retrograde orientation in the two antegrade branches supplying the IA and LCCA and one retrograde branch to the LSA-triple-branched and 3R-triple-branched endografts demonstrated marked increases in TAWSS (36.1% vs 50.2%, respectively), despite there being no significant change in the mean flow rate. Although maximum DF varied between devices (single-branched, 32.8 N; double-branched, 23.9 N; 2A+1-triple-branched, 22.9 N; 3R-triple-branched, 28.9 N), a post hoc analysis showed that branch configuration did not significantly influence DF. CONCLUSIONS: The hemodynamic stability within the aortic arch improves with a greater number of endograft side branches. Retrograde branch orientation does not significantly affect flow rates or SBP in the supra-aortic vessels. Among the evaluated designs, the triple-retrograde-branched configuration demonstrated the most favorable flow characteristics. CLINICAL RELEVANCE: Using patient-specific computational fluid dynamics simulations, this study compared the postimplantation local hemodynamic effects of single-, double-, and triple-branched endografts, using different configurations of antegrade and retrograde branches, in complex zone 0 aortic arch repair. Our study suggests two key findings: first, more branching improves hemodynamic stability by steadying blood flow, and second, the specific orientation of retrograde side branches does not affect the supra-aortic arteries. Properly validated, these findings may help to optimize branched endograft selection, ensuring stable hemodynamics for long-term patient success and device durability.