Technique to Detect Coil Migration Using Mask Images of Rotational Angiography During Stent-Assisted Coil Embolization for Ultra-wide Necked Aneurysms

A novel technique was developed to detect coil migration to the stent interior using mask images of rotational angiography. Stent-assisted coil embolization under x-ray fluoroscopy control was simulated with a hand-made vessel model. The stent interior was observed with a rigid endoscope during coil embolization. After insertion of the coil, mask images using rotational angiography were acquired and multi-planar reformation (MPR) images were reconstructed on a workstation. The stent interior could be observed during coil embolization. Longitudinal MPR images showed the positional relationships between the stent, coil, and tip of the microcatheter. This technique was successfully employed in a patient to detect displacement of the tip of the microcatheter inside the stent. This technique is useful for monitoring stent-assisted coil embolization of an ultra-wide necked aneurysm, but requires extra time and increased radiation exposure, so we recommend use only if coil migration is strongly suspected.