Development of a 3D Printed Benchtop Model of the Pulmonary System to Assist in the Development of Device to Treat Large Pulmonary Thrombo-embolic Disease

Pulmonary embolism (PE) can be life-threatening and is the third most common cause of cardiovascular mortality. For patients suffering from high and medium risk PE, potential treatments include a thrombolytic drug which is injected into the blood stream to dissolve the embolism. However, this treatment can increase the risk of bleeding occurring, particularly in susceptible patients. To reduce the level of drug required, it can be delivered directly to the site of the embolism through catheter-directed thrombolysis. Benchtop models have the potential to accelerate the development of catheter-based devices. Good benchtop models enable tests that allow issues to be identified and solved at an earlier stage in the development lifecycle, saving both time and money. In the present work, a patient-specific benchtop model of the relevant vascular anatomy has been proposed. Three different commercially available materials, namely Clear, Elastic, and Flexible from Formlabs, were evaluated for their capacity to represent the native anatomy. These materials were all 3D printable via stereolithography. Standard tensile and flexural testing samples were prepared and tested. The elastic material was far superior in resembling blood vessel’s mechanical properties. Computer tomography (CT) scans were used to develop a patient-specific benchtop model which includes Vena Cava, Right Heart, and Pulmonary Artery Computer Aided Design (CAD) models. Elastic material was used to 3D print the patient-specific models and assemble them for prototyping. A catheter was used for the demonstration of the developed benchtop model. The proposed methodology and material have shown successful candidacy to be used as a rapid method to create benchtop models that can test and validate catheter-based medical devices for the pulmonary system.