CT imaging of radiopaque shunt catheter after endolymphatic duct surgery.

Until now, shunt catheters used in endolymphatic sac (ELS) and duct surgery have not been visible at computed tomography (CT) imaging. This report summarizes findings at postoperative CT in 50 patients who underwent endolymphatic system decompressive surgery with a new opaque shunt catheter placed at or into the endolymphatic duct (ELD). The catheter was visible in all 50 cases, and the best projection for visualization was the semicoronal view. The postoperative visualization of the opaque shunt catheter allows determination of the exact placement of the catheter (a) in the bony vestibular aqueduct (within the membranous ELD); (b) at the external aperture of the bony vestibular aqueduct (within or at the membranous ELD at its junction with the ELS); or (c) outside the bony vestibular aqueduct system or aperture but presumably within the membranous ELS. These objective findings may be used as a marker to help predict outcomes from this type of nondestructive inner ear surgery, as well as to determine exactly where the surgeon placed the shunt-tube catheter tip.