Patient-Specific Vascular Modeling - Microsurgery: Advances, Simulations, and Applications - page 89

3.7 Reproduction of Surrounding Brain

Structure

Arterial model with soft membrane structure proposed in the
previous section allows simulating variety of medical treatment
including balloon PTA (percutaneous transluminal angioplasty)
and aneurismal neck clipping. However, since its structure does not
relect the existence of surrounding soft tissues (mainly composed of
very supple arachnoid tissue illed with cerebrospinal luid), which
actually supports most of the external force exerted on arterial wall,
it is dificult to keep its anatomically accurate coniguration in the
atmospheric condition. In human body, the elasticity of vascular
membrane and the existence of the surrounding soft tissue make
vascular structure to deform when catheter or other medical tools
are operated. And its soft structure even deforms against pulsation
and blood streaming. Some neurovascular treatments are executed
using this property, e.g., the expansion of narrowed artery (stenosis)
with balloons and stents and aneurismal clipping. However, this
property poses some technical dificulties, too. Therefore, it is
necessary to reproduce the composite elastic structure composed of
vascular membrane and surrounding brain structure.

2 0 m m

Figure 3.11 Arterial mode with composite structure reproducing
membranous arterial structure and surrounding visco-elastic
structure.

To reproduce these characteristics, we constructed a membranous
cerebral arterial model surrounded by brain-like soft structure
(Fig. 3.11). In this procedure, irst we arranged the above-fabricated
membranous vascular model inside a cubic mold according to its