A Finite Element Study of Human Pulmonary Autograft Wall Stress after the Ross Procedure

Abstract Dilatation of the pulmonary autograft after the Ross procedure can lead to aortic insufficiency and/or aneurysmal pathology requiring reoperation. Autograft remodeling occurs as the autograft wall is exposed to systemic pressure and higher wall stresses, which have not been quantified in humans. The aim of the study was to develop a realistic Finite Element (FE) model of the human pulmonary autograft and to perform simulations at systemic pressure to quantify the increases in autograft wall stress immediately after the Ross procedure. Autograft geometry was generated from high-resolution micro-computed tomography images of an explanted human pulmonary root to create a mesh of hexahedral elements. Constitutive equations were used to describe the regional tissue material properties of the human pulmonary root obtained from bi-axial stretch testing. LS-DYNA (LSTC Inc., Livermore, CA) FE software was used to simulate cardiac cycles at pulmonary and systemic pressure. Autograft dilatation and wall str...