[1] Boston Univ, Boston Med Ctr, Dept Surg, Chobanian & Avedisian Sch Med, Boston, MA USA
[2] Johns Hopkins Univ, Dept Surg, Sch Med, Baltimore, MD USA
[3] Boston Univ, Boston Med Ctr, Chobanian & Avedisian Sch Med, Dept Gastroenterol, Boston, MA USA
[4] Boston Univ, Boston Med Ctr, Chobanian & Avedisian Sch Med, Dept Radiol, Boston, MA USA
[5] Boston Med Ctr, Surg Sect Surg Oncol, 820 Harrison Ave,FGH Bldg,Suite 5007, Boston, MA 02118 USA
[6] Boston Med Ctr, Gastroenterol, 85 E Concord St, 7th Floor, Boston, MA 02118 USA