A computer-based visualization system for visualizing an anatomical structure and a graft implant which is to be deployed adjacent the anatomical structure, comprising: a 3-D computer model of the anatomical structure to be visualized, the 3-D computer model comprising at least one first software object which corresponds to the anatomical structure to be visualized; a database of second software objects, wherein at least one of the second software objects corresponds to a graft implant which is to be deployed adjacent the anatomical structure; selection apparatus for permitting a user to select at least one of the second software objects; registration apparatus for positioning the selected at least one of the second software objects into the 3-D computer model so as to create an augmented 3-D computer model; and processing apparatus for generating an image of the augmented 3-D computer model.