3D‐Printed Patient‐Specific Circles of Willis with an Intracranial Aneurysm and their Application to Neurointerventional Endovascular Simulation

Cerebrovascular replicas are effective platforms that can simulate endovascular interventions in the treatment of intracranial aneurysm (IA), and an IA typically forms in the tortuously structured cerebral artery circulation known as the circle of Willis (CoW). Effective and reliable endovascular procedure simulation before actual clinical treatment is greatly helpful for neurosurgeons, but the simulation performance depends on how identical a CoW replica is to a patient's CoW. Herein, a tubular, transparent, and patient‐specific CoW replica is fabricated with realistic dimensions and elasticity using a combination of 3D printing and dip coating technique. First, a real‐scale CoW core substrate is constructed using an extrusion‐based 3D printing technology, then the thickness of the vascular wall is manipulated by coating the core substrate layer by layer, and finally the core substrate is dissolved to produce a tubular CoW structure. A liquid‐assisted dip coating method is utilized and optimized for uniform and high‐quality coating layers on the tortuous CoW core substrate. Moreover, the effectiveness of the CoW replica is demonstrated through an in‐house neurointerventional endovascular simulator. The proposed method paves a new way for practical and reliable endovascular simulations, which would help significantly improve the clinical outcomes of current IA treatments. Reliable endovascular simulation of the intracranial aneurysm treatment requires a cerebrovascular replica identical to a patient's circle of Willis (CoW), which is challenging due to structural complexity. This article presents the fabrication of a patient‐specific CoW replica with realistic dimension and elasticity and demonstrates the effectiveness of the fabricated CoW replica in an endovascular procedure simulation.