[1] MIT, Dept Mech Engn, Cambridge, MA 02139 USA
[2] Harvard Med Sch, Brigham & Womens Hosp, Div Gastroenterol Hepatol & Endoscopy, Boston, MA 02115 USA
[3] MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA
[4] Harvard Univ, Boston, MA 02138 USA
[5] MIT, Div Comparat Med, Cambridge, MA 02139 USA
[6] Massachusetts Gen Hosp, Div Plast & Reconstruct Surg, Boston, MA 02114 USA
[7] Massachusetts Gen Hosp, Dept Radiol, Div Intervent Radiol, Boston, MA 02114 USA