Cardiac multislice computed tomography after transcatheter aortic valve implantation: Features after 'valve-in-valve' implantation for degenerative stented aortic bioprosthesis

摘要

An 86-year-old woman complained of gradually increasing dyspnoea (New York Heart Association stage III). Ten years previously she had surgical aortic valve replacement with a stented bioprosthesis (21 mm Carpentier-Edwards; Edwards Lifesciences, Irvine, CA, USA) for severe symptomatic aortic stenosis. At the same time, a triple coronary bypass graft was performed. Five years after surgery, a permanent pacemaker was implanted. Follow-up transthoracic echocardiography demonstrated severe stenosis of the aortic bioprosthesis (maximal pressure gradient 80mmHg; aortic valve area 0.6 cm~2). Surgery was contraindicated (logistic EuroSCORE greater than 20%). The patient was referred to our centre for transcatheter aortic valve implantation (TAVT). Preimplantation multislice computed tomography (MSCT)-angiography confirmed the feasibility of the transfemoral approach, then a 23 mm Edwards SAPIEN XT bioprosthesis (Edwards Lifesciences) was successfully implanted from a right trans-femoral approach. Immediate follow-up was unremarkable with no significant aortic regurgitation. Cardiac CT angiography (HD750 Discovery; General Electric, Milwaukee, USA) was performed 5 days after TAVI to evaluate the SAPIEN XT bioprosthesis positioning and deployment into the underlying Carpentier-Edwards bioprosthesis. The Edwards-SAPIEN XT biopros-thesis was precisely implanted at the basal level of the degenerative bioprosthesis (Fig. 1A and B). Circularity was good but, as expected, expansion of the SAPIEN XT was sub-optimal at the basal level due to the 19 mm underlying stent (diameter 18.5x18.1 mm, measured surface 2.67cm~2, expected surface 4.15cm~2) (Fig. 1C and D). By comparison, on the aortic side of the SAPIEN bioprosthesis, expansion was optimal (Fig. 1E and F; diameter 23.7x22.5mm, measured surface 4.19cm2). Three-dimensional volume-rendering reconstructions accurately demonstrated the close link between the two stents (Fig. 1G and H).