An Artificial Right Ventricle for Failing Fontan: In Vitro and Computational Study
| Autor: | Robin Shandas, Steven Goldberg, Rui Wang, Serban Stoica, Craig Lanning, François Lacour-Gayet, Bryan Rech |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Pulmonary and Respiratory Medicine
medicine.medical_specialty Cardiac output Suction Central Venous Pressure Heart Ventricles Ventricular Dysfunction Right Hemodynamics In Vitro Techniques Fontan Procedure Sensitivity and Specificity Risk Factors Internal medicine medicine.artery medicine Humans Computer Simulation Pulmonary Wedge Pressure Pulmonary wedge pressure Axial-flow pump business.industry Models Cardiovascular Central venous pressure Surgery medicine.anatomical_structure Regional Blood Flow Ventricle Pulmonary artery Cardiology Heart-Assist Devices Stress Mechanical Cardiology and Cardiovascular Medicine business |
| Zdroj: | The Annals of Thoracic Surgery. 88:170-176 |
| ISSN: | 0003-4975 |
| DOI: | 10.1016/j.athoracsur.2009.03.091 |
| Popis: | Background The aim of this study is to develop a destination low-pressure artificial right ventricle (ARV) to correct the impaired hemodynamics in the failing Fontan circulation. Methods An in vitro model circuit of the Fontan circulation was created to reproduce the hemodynamics of the failing Fontan and test ARV performance under various central venous pressures (CVP) and flows. A novel geometry of the extracardiac conduit was designed to adapt to the need of the pump. The ARV was a low-pressure axial flow pump designed to produce a low suction inflow pressure and moderate outflow increase. With the power off, the passive forward gradient across the propeller is 2 mm Hg at 4.5 L/min. The ARV would require 4 watts at a rotation of 5000 rpm. To examine the shear loading on the red blood cells, virtual particles were injected upstream of the ARV inducer and tracked by computerized modeling. Results The effect of the ARV on the failing Fontan was studied at various CVP pressures and flows, and under constant values of lung resistances and left atrial pressure set respectively to 2.5 Woods Units and 7 mm Hg. The CVP pressures decreased respectively from 25, 22.5, 20, 17.5, 15, and 10 mm Hg to a minimal value of 2 to 5 mm Hg with a pump speed varying from 1700 to 4500 rpm. The pulmonary artery pressures increased moderately between 12.5 and 25 mm Hg at 4500 rpm. Cardiac output at 4500 rpm was increased by an average gain of 2 L/min. The average blood damage index was 0.92%, far below the 5% value considered to cause hemolysis. The flow structure produced by the pump was suitable. Conclusions The performance of this novel low-pressure ARV was satisfactory, showing good decrease of CVP pressures, a moderate increase of pulmonary artery pressures, adequate increase of cardiac output, and minimal hemolysis. The use of a mock Fontan model circuit facilitates device prototyping and design to a far greater extent than can be achieved using animal studies, and is an essential first step for rapid design iteration of a novel ARV device. The next steps are the manufacturing of this device, including an electromagnetic engine, a regulatory system, and further testing the device in a survival animal experiment. |
| Databáze: | OpenAIRE |
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