Biomechanical Analysis of the Ross Procedure in an Ex Vivo Left Heart Simulator

Amelia Y. Bryan, E. Brandon Strong, Sumanth Kidambi, Shane Gilligan-Steinberg, Ross Bennett-Kennett, James Y. Lee, Annabel Imbrie-Moore, Stephen C. Moye, Sebastian Hendrickx-Rodriguez, Hanjay Wang, Reinhold H. Dauskardt, Y. Joseph Woo, Michael R. Ma

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Background: Neo-aortic pulmonary autografts often experience root dilation and valve regurgitation over time. This study seeks to understand the biomechanical differences between aortic and neo-aortic pulmonary roots using a heart simulator. Methods: Porcine aortic, neo-aortic pulmonary, and pulmonary roots (n = 6) were mounted in a heart simulator (parameters: 100 mm Hg, 37 °C, 70 cycles per minute, 5.0 L/min cardiac output). Echocardiography was used to study root distensibility (percentage change in luminal diameter between systole and diastole) and valve function. Leaflet motion was tracked with high-speed videography. After 30 min in the simulator, leaflet thickness (via cryosectioning), and multiaxial modulus (via lenticular hydrostatic deformation testing) were obtained. Results: There were no significant differences between aortic and neo-aortic pulmonary leaflet motion, including mean opening velocity (218 vs 248 mm/s, P =.27) or mean closing velocity (116 vs 157 mm/s, P =.12). Distensibility was similar between aortic (8.5%, 1.56 mm) and neo-aortic pulmonary (7.8%, 1.12 mm) roots (P =.59). Compared to virgin controls, native pulmonic roots exposed to systemic pressure for 30 min had reduced leaflet thickness (630 vs 385 µm, P =.049) and a reduced Young's modulus (3,125 vs 1,089 kPa, P =.077). In contrast, the aortic roots exposed to pressure displayed no significant difference in aortic leaflet thickness (1,317 vs 1,256 µm, P =.27) or modulus (5,931 vs 3,631 kPa, P =.56). Conclusions: Neo-aortic pulmonary roots demonstrated equivalence in valve function and distensibility but did experience changes in biomechanical properties and morphology. These changes may contribute to long-term complications associated with the Ross procedure.

Original languageEnglish
Pages (from-to)166-174
Number of pages9
JournalWorld journal for pediatric & congenital heart surgery
Volume13
Issue number2
DOIs
StatePublished - Mar 2022
Externally publishedYes

Keywords

  • Ross operation
  • aortic root
  • aortic valve
  • autograft
  • pulmonary valve
  • replacement

Fingerprint

Dive into the research topics of 'Biomechanical Analysis of the Ross Procedure in an Ex Vivo Left Heart Simulator'. Together they form a unique fingerprint.

Cite this