Cerebrovascular modelling for the management of aneurysm embolization using an intrasaccular flow diverter made by 3D printing

Introduction
Using 3-dimensional (3D) printers, the creation of patient-specific models is possible before and after a therapeutic intervention. There are many articles about replicas for training and simulation of aneurysm clipping. However, no paper has focused on 3D replicas obtained from 3-tesla 3D time of flight (3D-TOF) MR angiography for intrasaccular flow diverter (WEB device) embolization of the cerebral aneurysms. In this paper, we aimed to investigate the feasibility of 3D printing models obtained from 3-tesla 3D-TOF data in the management and training of WEB-assisted embolization procedures.

Case presentation
We presented a longitudinal case report with several 3D-TOF MRA prints over time. Three-tesla 3D-TOF data were converted into STL and G-code files using an open-source (3D-Slicer) program. We built patient-specific realistic 3D models of a patient with a middle cerebral artery trifurcation aneurysm, which were able to demonstrate the entire WEB device treatment procedure in the pre-intervention and post-intervention periods. The aneurysmatic segment was well displayed on the STL files and the 3D replicas. They allowed visualization of the aneurysmatic segment and changes within a 6-year follow-up period. We successfully showed the possibility of fast, cheap, and easy production of replicas for demonstration of the aneurysm, the parent vessels, and post-intervention changes in a simple way using an affordable 3D printer.

Conclusions
3D printing is useful for training the endovascular team and the patients, understanding the aneurysm/parent vessels, and choosing the optimal embolization technique/device. 3D printing will potentially lead to greater interventionalist confidence, decreased radiation dose, and improvements in patient safety.