Computed tomography optimised fluoroscopy guidance for transcatheter mitral therapies

Our aim was to illustrate the pragmatic use of pre-procedural multislice computed tomography (MSCT) to facilitate fluoroscopy guidance of transcatheter mitral valve interventions.A dedicated software package (3mensio Structural Heart) is used to analyse MSCT studies and localise anatomical entities by fluoroscopy which would otherwise be invisible (e.g., interatrial septum, paravalvular leaks, mitral leaflets), and to provide optimal C-arm gantry angles to facilitate crucial steps of catheter-based mitral interventions. For any given anatomical structure that has been identified by MSCT scan, a line of perpendicularity can be drawn representing an infinite combination of RAO-LAO with cranial-caudal angles. Safety and ergonomic considerations drive the selected angulation to be used in the cathlab. The location of the fossa ovalis can be projected onto the fluoroscopy screen to help direct the needle for transseptal puncture. For MitraClip implantations a C-arm gantry projection that is either coaxial or perpendicular to the mitral coaptation plane helps to orientate the clip before entering the left ventricle to grasp the mitral leaflets. A periprosthetic mitral leak can be localised relative to the prosthesis in the proposed C-arm angle. Pre-procedural MSCT is thus complementary to transoesophageal echocardiography for transcatheter mitral interventions.Determination of optimal C-arm angulations helps localise anatomical entities by fluoro-scopy and may expedite complex mitral interventions.