Abstract 16869: Perioperative DynaCT for Improved Imaging During Transapical Aortic Valve Implantation
Objective: Transcatheter aortic valve implantation (AVI) requires optimal fluoroscopic imaging. Exact perpendicular angulation of the fluoroscopic system (C-arm) in relation to the aortic annulus is crucial. Improved imaging, such as three dimensional aortic root images reconstructed from a rotational angiography (DynaCT) may provide a valuable guiding tool.
Methods: DynaCT was performed in 50 patients during transapical AVI using an angiographic imaging system (Artis zee / zeego, Siemens AG, Forchheim, Germany). DynaCT consisted of rotational angiography performed under rapid pacing with diluted contrast (25cc) followed by automatic segmentation of the aortic root including automatic detection of the coronary ostia (software prototype). The segmented image was displayed in an online overlay mode. Based on automatically detected lowest point of each aortic sinus (nadir) the system displays a graphical guiding-tool (A, B) to obtain an exact perpendicular C-arm angulation. Accuracy of the overlay was assessed during final root angiography (C). Perpendicularity of the C-arm angulation was evaluated (D) by measuring the valve-tilting angle after implantation.
Results: All valves were safely implanted. The online overlay demonstrated a mean deviation of 3.9±3.1mm (vertical) and 2.7±2.2mm (horizontal). In 84% (n=42) of patients the guiding-tool led to an exactly perpendicular C-arm angulation indicated by a valve-tilting within a range of 0–10°. In 12% (n=6) the angulation was still acceptable (10–12°) and borderline (>15°) in 4% (n=2).
Conclusions: Intraoperative DynaCT is a valuable guiding tool during transapical AVI. Automatic segmentation and detection of landmarks are feasible. Dyna-CT guided angulation of the C-arm results in an optimal perpendicular fluoroscopic view onto the aortic annulus in the majority of patients. Online overlay is helpful during valve implantation, however, a tracking mechanism will have to be implemented in the future.
- © 2010 by American Heart Association, Inc.