1. General Surgery Department, Hospital Metropolitano , Quito 170508 , Ecuador
2. General and Laparoscopic Surgery, Universidad Internacional del Ecuador , Quito 170411 , Ecuador
3. Universidad UTE, Avenida Mariscal Sucre s/n y Mariana de Jesús , Quito 170129 , Ecuador
4. Faculty of Medicine, Universidad Central del Ecuador , Quito 170136 , Ecuador