Abstract
A 72-year-old patient with quadricuspid aortic valve underwent transcatheter aortic valve replacement due to severe valve stenosis accompanied by moderate insufficiency. As initially planned, the right coronary artery was protected during the procedure. However, after the artificial valve was released, the left coronary artery was found to be blocked, so a coronary protection stent was implanted in the left coronary artery ostium under the guidance of intravascular ultrasonography. This case indicates that for patients with a quadricuspid aortic valve undergoing transcatheter aortic valve replacement, in addition to preoperative measurement of the aortic root, attention should also be paid to the coronary artery obstruction caused by the displacement of the artificial valve frame during the procedure.