Comparing Measurements of the Aortic Valve Taken During Surgery With Those Obtained Before Surgery Using Computed Tomography Scans, in Patients Undergoing Surgical Aortic Valve Replacement

"All patients with severe aortic stenosis (AS) who are scheduled for Surgical Aortic Valve Replacement (SAVR) with a bioprosthetic valve will undergo a pre-operative Computed Tomography (CT) scan. This CT scan will follow the pre-Transcatheter Aortic Valve Replacement (pre-TAVR) protocol and will focus only on imaging the aortic root, using a method called retrospective electrocardiogram (ECG) gating to capture detailed heart motion.~The measurements taken from the CT scan will be used to determine the appropriate size for two types of theoretical Transcatheter Aortic Valve Replacement (TAVR) prostheses:"