Evaluation of personalized right ventricle to pulmonary artery conduits using in silico design and computational analysis of flow

Abstract

Objectives: Right ventricle to pulmonary artery (RV-PA) conduits are required for the surgical management of pulmonary atresia with ventricular septal defect and truncus arteriosus. Bioengineered RV-PA connections may address some of the shortcomings of homografts and xenografts, such as lack of growth potential and structural deterioration and may be manufactured to accommodate patientspecific anatomy. The aim of this study was to develop a methodology for in silico patient-specific design and analysis of RV-PA conduits.Methods: Cross-sectional imaging was obtained from patients with truncus arteriosus (n ¼ 5) and pulmonary atresia with ventricular septal defect (n ¼ 5) who underwent complete repair with a RV-PA conduit. Three-dimensional models of the heart were constructed by segmentation of the right ventricle, existing conduit, branch pulmonary arteries, and surrounding structures. A customized conduit design for each patient was proposed. Computational fluid dynamics analysis was performed and outputs, including wall shear stress and energy loss, were used to compare the performance of the existing conduits and the customized geometries.Results: In this study, a methodology for patient-specific analysis of RV-PA conduit in silico was developed. The results of simulations for 10 patients showed between 23% and 56% decrease in the average wall shear stress and between 24% and 87% reduction in average power requirements in customized designs compared with the stenosed conduits, translating into better hemodynamic performance.Conclusions: Creation of an optimal conduit for an individual patient can be achieved using surgeon-guided design and computational fluid dynamics analysis. Manufacture of personalized RV-PA conduits may obviate the need for surgical customization to accommodate existing materials and provide superior longterm outcomes. (JTCVS Open 2020;1:33-48) Initial conduit and customized design showing improved wall shear stress distribution. CENTRAL MESSAGEPatient-specific design and in silico testing of novel RV-PA conduits is feasible and will complement emerging RV-PA technologies. PERSPECTIVERight ventricle to pulmonary artery conduits are an essential part of many pediatric cardiac reconstructions. We demonstrate that in silico patientspecific design and analysis of the proposed conduit is feasible. Iterative customization improves hemodynamic performance with potential benefits in reducing right ventricle work and durability. This approach may be employed with new generation polymer-based conduits.See Commentary on page 49.

Non-Newtonian Effects of Blood Flow on Hemodynamics in Pulmonary Stenosis: Numerical Simulation

“…Previous studies on the hemodynamics of pulmonary artery in zero-/one-dimensional, three-dimensional (3D), and multiscale models used computational fluid dynamics (CFD) to understand the pulmonary blood flow environment, wall deformation, and other conditions. Under the conditions of stability and blood flow, researchers established three different geometric models of the human pulmonary vascular system to conduct the coupling simulation of blood flow and drug particles [12][13][14][15]. A lot of work claimed that the blood flow problem had dual behavior, namely, Newtonian and non-Newtonian.…”

Verification of fluid-structure interaction modelling for wave propagation in fluid-filled elastic tubes

“…Our applications include modelling of an apparatus being developed to study digestion 1 and ducts containing replacement heart valves. 2…”

“…Our applications include modelling of an apparatus being developed to study digestion 1 and ducts containing replacement heart valves. 2 The equations relating to PWV have been developed for over a century. The most famous formula is the Moens-Korteweg equation, 3,4 developed in 1878.…”

Commentary: In silico design of right ventricle to pulmonary artery conduits—confirmation of “in cerebral” design?

“…1,2 This clinical situation motivates the study by Ebrahimi and colleagues. 3 In this study, the authors generated a model for the optimal right ventricle-to-pulmonary artery conduit using computational fluid dynamics and 3-dimensional imaging data from 5 patients who presented with right ventricle-to-pulmonary artery conduit failure. The Central Figure and Figure 5 of their manuscript summarize the results nicely: the failed conduits requiring replacement are narrowed and stenotic whereas the predicted, optimal in silico model has a larger caliber…”