Asymmetric Dynamics of the Native Aortic Annulus Evaluated by Force Transducer and Sonomicrometry in a Porcine Model

Leila Louise Benhassen,Diana Mathilde Ropcke,Jens Kæstel Skov,John Michael Hasenkam,Tommy Bechsgaard,Søren Nielsen Skov,Troels Lading,Sten Lyager Nielsen

doi:10.1007/s13239-019-00418-1

Leila Louise Benhassen, Diana Mathilde Ropcke + Show 6 more

Open Access

https://doi.org/10.1007/s13239-019-00418-1

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Abstract

PurposeWith new repair techniques of the aortic root and valve emerging, a detailed understanding of the dynamics of the aortic annulus and valve is required for optimal results. The objective of this study was to characterize geometrical changes and force distribution of the native porcine aortic annulus throughout the cardiac cycle.MethodsMeasurements were performed in an acute 80 kg porcine model (n = 7) using sonomicrometry crystals in the aortic annulus for evaluation of geometry and dynamics, annular force transducer evaluating force distribution, and pressure measurements and echocardiography evaluating valve performance.ResultsOverall, segmental force distribution and geometrical changes differed between different segments of the aortic annulus. The highest force development was found at the left/right interleaflet triangle (2.87 ± 2.1 N) and the largest segmental expansion was observed at the right-coronary and left-coronary sinus. The aortic annulus changed configuration throughout the cardiac cycle and became more oval in systole.ConclusionsThis study is the first to describe detailed segmental dynamics and force distribution of the native aortic annulus in a porcine model in vivo. The heterogenous behavior of the aortic annulus suggests that different segments demand different support for repair of the aortic root and valve.

Highlights

With the development of new surgical techniques for preservation and repair of the native aortic root and valve, a detailed understanding of the dynamics of the aortic annulus and valve is required
In this acute porcine open-chest model, we evaluated the dynamics of the aortic annulus with segmental force- and geometrical measurements
The model was successful for the intended characterization with a dedicated force transducer to evaluate force distribution, and sonomicrometry crystals to measure geometrical changes throughout the cardiac cycle

Summary

Introduction

With the development of new surgical techniques for preservation and repair of the native aortic root and valve, a detailed understanding of the dynamics of the aortic annulus and valve is required. Because of the anatomic asymmetry, the dynamics and force distribution of the aortic annulus is expected to be asymmetric throughout the cardiac cycle, but these aspects are not well understood. Few studies have been performed with characterization of the aortic annulus as being oval in diastole and round in systole or primarily oval in both systole and diastole.. The segments in which the expansion primarily occur and how this affect the force distribution in the aortic annulus have not previously been described. A detailed anatomical description of the aortic annulus throughout the cardiac cycle is needed in order to understand this complex structure and its role in the dynamic Previous studies using sonomicrometry have been limited by using only three crystals in the aortic annulus, making it harder to gain detailed segmental geometrical data. A detailed anatomical description of the aortic annulus throughout the cardiac cycle is needed in order to understand this complex structure and its role in the dynamic

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