Multimodality image fusion guidance in the microcatheter navigation to cerebrospinal arteriovenous fistula: Report of the two cases

Background: Neuroendovascular treatments, particularly transvenous embolization, require precise visualization of the approach route during microcatheter navigation. However, conventional roadmaps often face limitations, such as contrast medium dilution and slow venous flow. The multimodal image fusion guidance system integrates pre-acquired imaging datasets, such as computed tomography venography, with real-time fluoroscopy to enhance the visualization of the vascular anatomy and procedural accuracy. This report highlights the efficacy of this system in navigating microcatheters to complex arteriovenous fistulas (AVFs) using a transvenous approach. Case Description: Case 1 involved a 75-year-old woman with a left cavernous sinus dural AVF, which was treated using a transvenous approach through the facial vein. The multimodal image fusion guidance system enabled precise catheter navigation, resulting in complete obliteration of the shunt with coils. Case 2 involved a 45-year-old man with a spinal epidural AVF. This system facilitated accurate catheterization of the epidural venous plexus through the hemiazygos vein, enabling successful embolization with coils. Conclusion: The multimodal image fusion guidance system enhances visualization and catheter navigation, addressing the challenges inherent in transvenous procedures. These cases demonstrate its efficacy in improving procedural safety and precision in complex neurovascular conditions. Although limitations include dependence on pre-acquired images and potential misalignment due to vessel shifts, this system represents a significant advancement in neuroendovascular navigation. Further studies are warranted to evaluate its broader applicability and impact on clinical outcomes.