Introduction: The aim of this project was to construct a low cost customizable simulation system of aneurysms in the circle of Willis and its branches.
Methods: DICOM images from an MRA head were used to create a Stereolithography model of the circle of Willis using Materialise InPrint. A desktop 3D printer utilizing fused deposition modeling technology was used for 3D printing. Water-soluble polyvinyl alcohol (PVA) was used as the printing material for the arterial network. Two different concentrations of silicone in solvent were applied to the outer layer of the model, with the more flexible silicone applied to a desired area, such as the basilar tip, which would lead to development of aneurysm. Immersing the final product in water dissolved PVA, leaving a hollow elastic vascular model with thin walls. The designated open ends of the model were connected to a pressure-adjustable closed-circuit liquid circulation pump in order to simulate blood flow.
Results: The wall of the vascular system developed in this current technique, allows for a more realistic simulation when compared to models where the flexible vessel walls are directly 3D printed with PolyJet technology. This is due to the ability to create thinner walls as well as the ability to create larger and more complex vascular anatomy since no support material is needed for the long hollow tubular structure with overhanging edges. Furthermore, the aneurysms are the result of true wall protrusion with a tensile force developed in the walls of the aneurysm.
Conclusions: The hollow vascular system can be embedded in a soft model of brain parenchyma created through molding techniques to allow neurosurgical trainees to practice clipping of aneurysms that are truly the result of bulging of the vascular wall as opposed to the traditional directly 3D printed thick-walled static aneurysms.
Patient Care: Facing the pathology in a safe setting such as the one described in our work will potentially improve safety for the patients undergoing surgery.
Learning Objectives: Give trainees and surgeons an opportunity to study and practice the anatomy and steps for successful treatment of cerebral aneurysms.
References: 1. Pucci JU et al. “Three-Dimensional Printing: Technologies, Applications, and Limitations in Neurosurgery.” Biotechnology Advances, vol. 35, no. 5, Sept. 2017, pp. 521–29. ScienceDirect, doi:10.1016/j.biotechadv.2017.05.007.
2. Rengier F et al. “3D Printing Based on Imaging Data: Review of Medical Applications.” International Journal of Computer Assisted Radiology and Surgery, vol. 5, no. 4, July 2010, pp. 335–41, doi:10.1007/s11548-010-0476-x.
3. Ryan JR et al. “Cerebral Aneurysm Clipping Surgery Simulation Using Patient-Specific 3D Printing and Silicone Casting.” World Neurosurgery, vol. 88, no. Supplement C, Apr. 2016, pp. 175–81. ScienceDirect, doi:10.1016/j.wneu.2015.12.102.