Novel insights by 4D Flow imaging on aortic flow physiology after valve-sparing root replacement with or without neosinuses

Nicola Galea, Filippo Piatti, Francesco Sturla, Jonathan W. Weinsaft, Christopher Lau, Ilaria Chirichilli, Iacopo Carbone, Emiliano Votta, Carlo Catalano, Ruggero De Paulis, Leonard N. Girardi, Alberto Redaelli, Mario Gaudino

Research output: Contribution to journalArticle

Abstract

OBJECTIVES This study was undertaken to evaluate the flow dynamics in the aortic root after valve-sparing root replacement with and without neosinuses of Valsalva reconstruction, by exploiting the capability of 4D Flow imaging to measure in vivo blood velocity fields and 3D geometric flow patterns. METHODS Ten patients who underwent valve-sparing root replacement utilizing grafts with neosinuses or straight tube grafts (5 cases each) were evaluated by 4D Flow imaging at a mean of 46.5 months after surgery. We used in-house processing tools to quantify relevant bulk flow variables (flow rate, stroke volume, peak velocity and mean velocity), wall shear stresses and the amount of flow rotation characterizing the region enclosed by the graft and the aortic valve leaflets. RESULTS Despite bulk flows with similar peak velocities, flow rates and stroke volumes (P = 0.31-1.00), the neosinuses graft was associated with a lower mean velocity (P < 0.03) and magnitude of wall shear stress along the axial direction of the vessel wall (P < 0.05) at the proximal root level but remained comparable along the circumferential direction (P = 0.22-1.0) to the straight tube graft. Flow rotation was evidently and systematically higher in the neosinuses grafts, characterized by streamline rotations higher than 270°, nearly triple that of tubular grafts (10.3 ÷ 14.0% of all aortic streamline vs 2.2 ÷ 5.7%, P = 0.008). CONCLUSIONS Recreation of the sinuses of Valsalva during valve-sparing root replacement is associated with significantly lower wall shear stress and organized vortical flows at the level of the sinus that are not evident using the straight tube graft. These findings need confirmation in larger studies and could have important implications in terms of aortic valve durability.

Original languageEnglish
Pages (from-to)957-964
Number of pages8
JournalInteractive Cardiovascular and Thoracic Surgery
Volume26
Issue number6
DOIs
Publication statusPublished - Jun 1 2018

Keywords

  • 4D Flow imaging
  • Aortic root replacement
  • Neosinuses graft
  • Sinuses of Valsalva
  • Valve-sparing aortic root replacement
  • Vortex

ASJC Scopus subject areas

  • Surgery
  • Pulmonary and Respiratory Medicine
  • Cardiology and Cardiovascular Medicine

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    Galea, N., Piatti, F., Sturla, F., Weinsaft, J. W., Lau, C., Chirichilli, I., Carbone, I., Votta, E., Catalano, C., De Paulis, R., Girardi, L. N., Redaelli, A., & Gaudino, M. (2018). Novel insights by 4D Flow imaging on aortic flow physiology after valve-sparing root replacement with or without neosinuses. Interactive Cardiovascular and Thoracic Surgery, 26(6), 957-964. https://doi.org/10.1093/icvts/ivx431