C Claus1, F Malcher2, L T Cavazzola3. 1. Minimally Invasive Surgery Department, Jacques Perissat Institute, Positivo University, Jeremias Maciel Perretto St, 300, Curitiba, 81210-310, Brazil. christiano.claus@gmail.com. 2. Department of Surgery, Albert Einstein College of Medicine, Bronx, USA. 3. Department of Surgery, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.