A method for deploying a device in a tortuous vessel, comprising: creating a virtual representation of the tortuous vessel; placing a virtual generalized-cylinder within the virtual representation of the tortuous vessel, wherein the virtual generalized-cylinder is placed within the virtual representation of the tortuous vessel by (i) calculating the centerline of the virtual representation of the tortuous vessel, and (ii) generating the virtual generalized-cylinder by defining an extent along the centerline of the virtual representation of the tortuous vessel and constructing the virtual generalized-cylinder about the centerline; measuring length along the perimeter of the virtual generalized-cylinder at a pre-determined number of longitudes, wherein the longitudes extend parallel to the centerline, and further wherein measuring length along the perimeter of the virtual device at a pre-determined number of longitudes comprises marching down the centerline of the virtual generalized-cylinder, incrementally adding to an array of longitudinal length counters as progressing along the centerline; determining the maximum measured length; selecting a device based upon the maximum measured length; and deploying the device in the tortuous vessel.