Abstract 3036: Initial Experience With Aortic Root C-arm CT During Transcatheter Aortic Valve Implantation in Swine
Purpose: To evaluate the clinical feasibility of aortic root C-arm CT during transcatheter aortic valve implantation (TAVI) in swine.
Methods: Four pigs were imaged with C-arm CT (Axiom Artis, Siemens) during contrast injection into the aortic root. 5-sec ungated scans were performed during rapid ventricular pacing with 15–120 ml (0 –50% diluted Ultravist 240) at 5–20 ml/sec. 20-sec ECG-gated scans were performed during normal sinus rhythm with 120 –140 ml at 4 – 8 ml/sec. Two of the pigs were also imaged with ECG-gated helical MDCT (Definition, Siemens) following peripheral injection of 60 – 80 ml at 5– 6 ml/sec. C-arm CT images were qualitatively assessed for sufficient opacification in the aortic root and the best sets determined. In the best sets, coronary ostia was identified and diameter measurements of aortic annulus, sinus of valsalva, sinotubular junction, and mid-ascending aorta were attempted in reformatted sagittal and axial C-arm CT images. Comparison was made with MDCT.
Results: Aortic root injection resulted in sufficient root enhancement in ungated C-arm CT images, but insufficient enhancement in gated images. Sufficient enhancement for ungated C-arm CT during rapid pacing was observed with 75 ml of contrast at 13 ml/sec. Compared to MDCT, coronary artery ostia were identified in 88% of ungated images and all diameter measurements were feasible in sagittal ungated images. In axial ungated C-arm CT images, all measurements were feasible except annulus diameter due to lack of opacification below the valve.
Conclusion: Ungated C-arm CT during rapid pacing with contrast injection in aortic root allows intra-operative 3-dimensional imaging of the aortic root during TAVI.