Lesions were defined as distal stenoses if the tumor was located under in the area from union of the cystic duct to the bile duct. They were defined as proximal stenoses if the tumor was located above that same anatomical region.
Las lesiones fueron definidas como estenosis distal si el tumor se localizaba por debajo de la unión del conducto cístico a la vía biliar, y se consideró proximal si se localizaba por encima de dicho sitio anatómico.