An innovative ex-vivo model for rapid change of the papilla for teaching advanced endoscopic retrograde cholangiopancreatography procedures - Artifon, Everson L A; Nakadomari, Thaisa S; Kashiwagui, Leandro Y; Belmonte, Emilio A; Solak, Cláudio R; Cheng, Spencer; Furuya Junior, Carlos K; Otoch, José Pinhata (Arquivos Brasileiros de Cirurgia Digestiva, 2016)