Not sure about Nashville, but in Chattanooga Memorial Hospital's Weight Management Center will take Mexico patients. There numbers are: 423-495-2244, toll free 1-866-313-2244
http://www.memorial.org/body.cfm?id=275
They will charge you a little over $300 for the initial consult and approx. $250 for fill which they do a fluroscopy each time.
Pamela,
Chattanooga