Transcatheter Aortic Valve Replacement as a Treatment for Late Apicoaortic Conduit Obstruction in a Patient With Severe Aortic Stenosis

Abstract

A 62-year–old man presented with progressive exertional dyspnea and angina. His past medical history is notable for coronary artery disease, for which he underwent a coronary artery bypass graft surgery 8 years earlier. A few years afterward, he underwent aortic valve (AV) bypass (AVB) surgery for severe aortic stenosis (AS) using an apicoaortic conduit to the descending aorta consisting of a 16-mm connector and an 18-mm valved conduit (Hancock valve; Medtronic, Minneapolis, MN; Figures 1 and 2; online-only Data Supplement Movie I). After a period of initial improvement in symptoms, the patient developed progressive dyspnea and angina and was referred for additional cardiac workup. Figure 1. An ECG-gated thin-slice contrast-enhanced cardiac computed tomography scan showing a heavily calcified native aortic valve (AV), hypertrophied left ventricle (LV), and the apical LV insertion site of the apicoaortic valved conduit. Figure 2. A 3-dimensional cardiac computed tomography reconstruction image showing the apicoaortic valved conduit, extending from its apical insertion site into the left ventricle (LV) to its insertion site into the descending aorta. Arrow , Conduit valve. The patient underwent a bicycle ergometer test, which showed a diminished functional capacity and was stopped because of fatigue and a hypotensive response. He underwent a 2-dimensional transthoracic echocardiogram with gradual dobutamine infusion. He was found to have a heavily calcified AV (online-only Data Supplement Movie II) with a rest mean transvalvular gradient of 34 mm Hg and velocity of 3.5 m/s, which increased to 50 mm Hg and 4.8 m/s, respectively, at peak dobutamine dose (Figure 3). This corresponded with a …