CONTOUR SIMULATION STUDY

The novel Contour Neurovascular System (CNS) has been reported to lead to high
occlusion rates in wide necked intracranial aneurysms (Liebig et al. 2022). However, in
10-30% of cases the CNS fails to achieve adequate occlusion of the aneurysms treated
(Gärtner et al. 2023). Among several factors, contributing to non-complete occlusion of
aneurysms after treatment with CNS device placement and sizing are very likely the most
relevant ones. To get a better understanding of the processes leading to incomplete
occlusion after CNS placement in vitro and in silico simulations may help to improve
treatment outcomes in the future.
To investigate the different research objectives, an excellent infrastructure is available at
the Research Campus STIMULATE. Patient-specific intracranial aneurysm cases, which
are acquired multicentrically, are segmented and converted into virtual 3D printable hollow
vascular models. Using the high-resolution stereolithography-based 3D printing method
with a Formlabs Form 3+ (Formlabs, Somerville, MA, USA) as well as the Prusa SL1S
(Prusa Research a.s., Prague, Czech Republic), the segmented aneurysms are
manufactured (see Figure 1). The different patient-specific phantom models can be
correctly positioned for each patient in a 3D-printed skull model with a high concentration
of stone powder. This setup enables individual placement of the vessels and the skull
model achieves radiation attenuation in the angiography system close to reality (see
Figure 2).
Using a pulsatile flow pump (FlowTek 125, United Biologics, Inc., Irvine, CA, USA) in
combination with selective contrast media injection, a neurovascular training setup for the
CNS placement training inside the in-house angiography machine (ARTIS icono biplane,
Siemens Healthineers AG, Erlangen, Germany) can be realized.
Furthermore in-silico investigations will be carried out to examine the resulting flow
modulation and treatment effect on the flow. With the use of computational fluid dynamics,
various placement scenarios conducted in the neurovascular training setup can be
virtually recreated. This ensures insights into the flow patterns after the device deployment
and the hemodynamic effect on the treated aneurysms.