Abstract 11145: Biomechanical Engineering Analysis of Leaflet Kinematics and Native Coronary Flow After Valve-Sparing Aortic Root Replacement Using Four Graft Configurations

Abstract

Introduction: Different ex vivo root biomechanics after valve-sparing aortic root replacement (VSARR) using several graft configurations have been described. The impact of graft choice on each cusp’s kinematics and native coronary flow remains unclear. The objective was to analyze valve kinematics and coronary flow after VSARR using 4 graft configurations in a 3D-printed heart simulator ( Fig A ).[YZ1] Methods: Porcine aortic roots with coronary arteries were explanted (n = 5). Native roots served as controls ( Fig B ). Each sample underwent VSARR using straight graft (SG), Valsalva graft (VG), anti-commissural plication (ACP), and Stanford modification (SMOD) in a random order ( Fig C-G ). Hemodynamics and videometric data were analyzed ( Fig H, I ). Results: SG showed the lowest regurgitant fraction (2.8 ± 1.5 %) compared to control (6.3 ± 3.9 %, p = .0002), VG (12.2 ± 3.6 %, p = .002), ACP (12.9 ± 1.3 %, p = .001), and SMOD (12.2 ± 3.0 %, p = .001, Fig J, K ). The left coronary artery flow was higher in SG (0.68 ± 0.16 L/min) compared to VG (0.55 ± 0.22 L/min, p = 0.05) and SMOD (0.51 ± 0.23 L/min, p = 0.05, Fig L ). The right coronary artery flow was higher in SG (0.20 ± 0.10 L/min) compared to VG (0.07 ± 0.04 L/min, p = 0.04) and SMOD (0.08 ± 0.05 L/min, p = 0.04, Fig M ). SG (26.5 ± 17.6 cm/s) compared to VG (48.3 ± 19.0 cm/s, p = .001) and SMOD (39.5 ± 10.1 cm/s, p = .05) showed lower rapid opening velocity in the left coronary cusp (LCC). SG (8.1 ± 6.2 cm/s) compared to VG (15.0 ± 10.6 cm/s, p = .04) showed lower rapid closing velocity in the right coronary cusp. The VG (17.7 ± 9.7 Hz) had higher flutter frequency in the LCC compared to control (11.9 ± 4.1 Hz, p = .02). The SG (11.9 ± 4.5 dB/Hz) compared to ACP (16.4 ± 4.7 dB/Hz, p = .01) showed lower flutter power in the LCC. Conclusions: Compared to other configurations, SG had the most optimal hemodynamics, native coronary flow, and leaflet kinematics. Further in vivo validation studies should be performed to evaluate flow dynamics in the root and assess for clinical applicability.