1 research outputs found
Stretchable, Implantable, Nanostructured Flow-Diverter System for Quantification of Intra-aneurysmal Hemodynamics
Random
weakening of an intracranial blood vessel results in abnormal
blood flow into an aneurysmal sac. Recent advancements show that an
implantable flow diverter, integrated with a medical stent, enables
a highly effective treatment of cerebral aneurysms by guiding blood
flow into the normal vessel path. None of such treatment systems,
however, offers post-treatment monitoring to assess the progress of
sac occlusion. Therefore, physicians rely heavily on either angiography
or magnetic resonance imaging. Both methods require a dedicated facility
with sophisticated equipment settings and time-consuming, cumbersome
procedures. In this paper, we introduce an implantable, stretchable,
nanostructured flow-sensor system for quantification of intra-aneurysmal
hemodynamics. The open-mesh membrane device is capable of effective
implantation in complex neurovascular vessels with extreme stretchability
(500% radial stretching) and bendability (180° with 0.75 mm radius
of curvature) for monitoring of the treatment progress. A collection
of quantitative mechanics, fluid dynamics, and experimental studies
establish the fundamental aspects of design criteria for a highly
compliant, implantable device. Hemocompatibility study using fresh
ovine blood captures the device feasibility for long-term insertion
in a blood vessel, showing less platelet deposition compared to that
in existing implantable materials. <i>In vitro</i> demonstrations
of three types of flow sensors show quantification of intra-aneurysmal
blood flow in a pig aorta and the capability of observation of aneurysm
treatment with a great sensitivity (detection limit as small as 0.032
m/s). Overall, this work describes a mechanically soft flow-diverter
system that offers an effective treatment of aneurysms with an active
monitoring of intra-aneurysmal hemodynamics