Manufacturing of Ultrasound- and MRI-Compatible Aortic Valves Using 3D Printing for Analysis and Simulation

Abstract

Valve-related heart disease affects 27 million patients worldwide andis associated with inflammation,fibrosis and calcification which progressivelylead to organ structure change. Aortic stenosis is the most common valvepathology with controversies regarding its optimal management, such as thetiming of valve replacement. Therefore, there is emerging demand for analysisand simulation of valves to help researchers and companies to test novelapproaches. This paper describes how to build ultrasound- and MRI-compatibleaortic valves compliant phantoms with a two-part mold technique using 3Dprinting. The choice of the molding material, PVA, was based on its materialproperties and experimentally tested dissolving time. Different diseased valveswere then manufactured with ecoflex silicone, a commonly used tissue-mimicking material. The valves were mounted with an external support andtested in physiologicalflow conditions. Flow images were obtained with bothultrasound and MRI, showing physiologically plausible anatomy and function ofthe valves. The simplicity of the manufacturing process and low cost of mate-rials should enable an easy adoption of proposed methodology. Future researchwill focus on the extension of the method to cover a larger anatomical area (e.g.aortic arch) and the use of this phantom to validate the non-invasive assessmentof blood pressure differences.