Article Text
Abstract
Introduction Although current microcatheter technologies have advanced in recent years, corresponding endovascular models still lag behind. Animal models are unable to replicate consistent large and wide neck bifurcation aneurysms with sufficient neurovascular feeders. A system is needed that accurately models vessel tortuosity, flow patterns, detects downstream migration of neurovascular embolic devices, along with displaying and storing peri-procedural and long-term pressure and flow data. This submission utilizes an in-vitro flow model to test the stability of endovascular devices.
Materials and Methods This research brings together clinical, biological, and engineering expertise for the development of benchtop flow models for mechanical assessments of device stability. A full Circle of Willis (CW) in-vitro vessel model was fabricated into vessel analogs using a biomimetic photopolymer, Agilus30® and constructed using a PolyJet® (UV-cured) 3D-printing additive manufacturing process, capable of replicating accurate anatomical tortuosity. Typical aneurysm positions, verified by a collaborating neuro-interventional surgeon, was 3D-printed at the basilar bifurcation, the posterior communicating (PCA) branch, and at the anterior communicating (ACA) bifurcation (Abstract 139 figure 1).
CAD model of CW (Top) CW model interior (Bottom) Physiologically-relevant patient flow parameters were tuned within the system using a Super Pump AR (ViVitro Labs). A data acquisition system (DAQ) with LabVIEW® software recorded real time pressure and flow waveforms, mean arterial pressures (MAP) and flows through each inlet and outlet branch of the 3D-printed CW model. The flow model included an introducer for microcatheter and device delivery access
Results To confirm the usability of the flow model, a novel polymer aneurysm device, NeuroCURE®, was deployed under temporary balloon occlusion. The in-vitro model monitored real-time pressure information intra- and post-device delivery. Modified Raymond-Roy (MRR) was used to evaluate post-treatment. The Agilus30® model reproduced a working CW model, and the NeuroCURE device delivery provided validation of the surgical simulation technique. Real-time pressure and flow data provided a greater understanding of flow distribution throughout the CW.
Conclusion This in-vitro aneurysm flow model utilized the latest in UV-cured 3D-printing techniques to provide a realistic simulation of neurovascular tortuosity and aneurysm device delivery. Future additions to the comprehensive flow model include an inline imaging system to quantify any particles (number and size, in accordance with ((USP) XXV <788>) that may be released during endovascular device delivery. Lastly, the model will be a closed-loop sterile system that can run for up to one-month for long-term device integrity testing, complementing in vivo testing of device biocompatibility.
Disclosures N. Norris: None. K. Lewis: None. C. Settanni: None. T. Becker: 1; C; NIH grant# 5R42NS097069-03. A. Ducruet: None.