Development and Applications of a High Resolution Microangioscope for Intracranial Neuroendovascular Interventions
Jeremiah Johnson, Peter Kan, Jan-Karl Burkhardt, Michael Phillips, Roberto Garcia, Stephen Chen, Visish Srinivasan, Tyler Lazaro, Phillip Cooper, Dalis Collins
Introduction: Visualization in neuroendovascular interventions relies on biplanar fluoroscopy. Radiation and contrast-related complications are the two major drawbacks. Angioscopy, direct endoluminal optical visualization, does not require radiation or contrast but has limited utility in neurointerventions due to limitations in size and stiffness.
Objective: To develop a microangioscope compatible with the human cerebrovasculature. To explore its utility in routine neurointerventions.
Methods: We recently developed a microangioscope for neurointervention that has the miniaturization and flexibility necessary to navigate in small, tortuous vessels. The prototype is a coherent fiber bundle microangioscope embedded in a 0.0165” microcatheter, a microcatheter used for coil embolization of cerebral aneurysms. We tested its compatibility with the human intracranial vasculature in human cadaveric experiments and its its utility in routine neurointerventions in an in-vivo swine model.
Results: In human cadaveric experiments, the microangioscope is compatible with the human intracranial vasculature beyond the Circle of Willis (eg. navigation into and visualization of the M2 origin). In in vivo swine model experiments, the microangioscope has adequate resolution and illumination to identify and differentiate between various intravascular pathologies (eg. red thrombus versus white thrombus) and perform various common neurointerventions precisely under direct visualization: mechanical thrombectomy, coil embolization, stent deployment, and balloon angioplasty. After deployment, the microangioscope enables immediate and follow-up direct inspection of devices, providing complementary information to standard angiography.
Conclusions: Imaging quality, illumination, and flexibility of the microangioscope progressively improved through modifications to the image bundle. Based on these results, the microangioscope is compatible with the human distal cerebrovasculature and provides adequate direct visualization for neurointerventions.