[1] Case Western Reserve Univ, Esophageal & Swallowing Ctr, Div Gastroenterol & Hepatol, MetroHlth Med Syst, Cleveland, OH 44106 USA
[2] Univ Hosp Cleveland, Digest Hlth Inst, Cleveland, OH 44106 USA
[3] ABC Med Ctr, Gastrointestinal Dept, Mexico City, DF, Mexico
[4] NYU, Dept Med, Langone Med Ctr, 550 1St Ave, New York, NY 10016 USA