3D-Printing and In Vitro Flow Experiments for Assessment of Aneurysm Treatment with Contour Neurovascular System
Please login to view abstract download link
Intracranial aneurysms (IAs) can be treated with flow-modulation devices (FMDs), but complications necessitate safer alternatives. Development of novel FMDs relies heavily on animal testing. Patient-specific 3D-printed IA models combined with in vitro flow experiments can provide a platform to assess FMD performance before animal studies. Here, we demonstrate this approach by evaluating the Contour Neurovascular System (CNS). IA models were constructed by segmenting vessels from medical radiological images, manually correcting segmentation errors, and adding vessel walls and flow connectors [1]. In total, 14 bifurcation tip aneurysm models were 3D printed using stereolithography (Form 3, Formlabs). Device deployment was performed by placing 10 CNS under fluoroscopy [2]. The models were then integrated into a flow loop and analyzed using digital subtraction angiography (DSA, Allura Xper, Philips), 4D flow magnetic resonance imaging (MRI, 3T, Philips, head coil), and numerical flow simulation (StarCCM+2021.3v16.6, Siemens) [3]. The resulting IA models reproduce key aneurysm flow features and are compatible with FMDs. All CNS devices were successfully implanted, resulting in reduced intra-aneurysmal flow, confirmed qualitatively by 4D flow MRI and quantitatively by increased contrast-agent stasis time on DSA (mean without (w/o) = 0.5 s; mean with (w/) = 2.3 s) and decreased intra-aneurysmal velocity from numerical simulations (mean w/o = 0.12 m/s; mean w/ = 0.03 m/s). IA models combined with in vitro experiments enable standardized optimization of new treatment options, reduce animal testing, and can be used to validate numerical simulations.
