1. Department of Surgery, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubiran, Mexico City, Mexico
2. Department of Surgery, Montefiore Medical Center, Bronx, New York, USA
3. Department of Anesthesiology, Hospital Memorial, Morelia, Mexico
4. Department of Colorectal Surgery, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubiran, Mexico City, Mexico