Measuring Mechanical Properties of 3D Printed Specimens for Creating Cerebral Aneurysm Mock-Ups for Surgical Training

In recent years, to improve the effectiveness of endovascular surgery for the treatment of intracranial aneurysms, study methods have been developed, involving the creation of 3D mock-ups through the use of additive manufacturing technology. Starting from computed tomography images, the use of additive manufacturing allows to create 3D models characterized by complex geometries. These mock-ups can be employed for surgical training to identify the various criticalities of the intervention, including the best approaches to the zone of interest and the choice of the most appropriate surgical tools. A crucial aspect is therefore represented by the mechanical properties of the mock-up, that must replace as close as possible that of the native tissues. In this work, we employed three different testing approaches, linear uniaxial, linear whole body and linear ring tests, to deeply characterize along the longitudinal and radial axes a series of specimens realized with “Formlabs Elastic 50A” and 3D printed with different orientation, namely 0°, 45°and 90°. Experimental results revealed that the stress-strain curves present a good linearity with values of
${{\mathrm{R}}^{2}}$
always higher than 0.99 for all the tested combinations of geometries and orientations. Moreover, we also demonstrated that the different printing orientation influenced the mechanical properties of the tested samples, for all the analyzed geometries, pinpointing a crucial aspect that must be considered when realizing very complex geometry, as intracranial vessels and aneurysms.