Flow diverters have generally been successful in the treatment of intracranial aneurysms; however, their utility has been limited by the device’s tendency to divert flow from healthy structures in the vicinity of the lesion site. Here, we show the potential for achieving flow diversion in a selective manner by utilizing an alternative approach in which high aspect-ratio microscale structures are intentionally designed to work congruently with an intermediate porosity flow diverter. We demonstrate this design principle through the realization of a microfabricated flow diverter with finely controlled cross-sectional elements. Using an in vitro basilar trunk model, we demonstrate comparable intra-aneurysmal flow reduction to commercially available flow diverters, while also demonstrating that such devices minimally affect flow into a “jailed” perforating artery (i.e., nearly-eight-fold lower perforator flow reduction than commercial device). This may provide an additional design parameter by which the indication of flow diversion devices may be extended into more delicate structures in the neurovasculature which currently lack a treatment option.

Flow diversion devices have generally been successful in the treatment of intracranial aneurysms. However, clinical complications have often been linked to complex and counter-intuitive mechanical responses which arise from the device’s braid-based design (e.g. poor wall apposition, excessive foreshortening, etc.). Herein, as a potential response to these issues, we demonstrate the feasibility of a novel microfabricated balloon-deployable flow diverter with finely controlled orthogonal cross-sectional elements which are monolithically integrated into a solid construct. Previous studies have mostly focused on characterizing flow diversion as a result of porosity in highly symmetric devices. By contrast, here we show that similar results can be achieved in more sparse and heterogeneous structures by utilizing basic principles of aerodynamics in micro-scale design (i.e. intentionally designing structural elements to induce drag). Computational and experimental models suggest the potential for such treatment, noting an average intra-aneurysmal velocity reduction of 86% and 88% ± 4% (n=3), respectively and reductions in average wall shear stress of 87% and 88% ± 4% (n=3). Experimental models showed agreement with computational models with the model’s predictive metrics for aneurysm occlusion falling within the 95% confidence interval for the experiments.