1 Basil I. Hirschowitz Endoscopic Center of Excellence, Division of Gastroenterology and Hepatology, Department of Internal Medicine, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA.
2 Division of Gastroenterology, Hepatology, and Endoscopy, Brigham and Women's Hospital - Harvard Medical School, Boston, Massachusetts, USA.
3 Endoscopy Unit, Gastrointestinal Department, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
4 Surgery Division, Federal University of Rio Grande do Norte, Natal, Brazil.