The small aortic root.
D000293:Adolescent; D001021:Aortic Valve / Q000033:anatomy & histology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D002404:Catheterization; D002648:Child; D002675:Child, Preschool; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000601:surgery; D006801:Humans; D008297:Male; D019736:Prostheses and Implants; D011859:Radiography