Since Von Winiwarter’s first biliodigestive anastomosis in 18801, several procedures have been tried intending to replace the main bile duct. Some of them were the performance of aponeurotic flaps, and the interposition of ureter, arteries and veins, cecal appendix, jejunum, gallbladder and tubes from different synthetic materials, as well as the adoption of various biliodigestive bypass procedures [2-24]. The malignant stenosis of the main bile duct represents a therapeutical problem for surgeons, although there are currently different treatment possibilities. These generally appear in an advanced stage, therefore, surgery ends up being a palliative procedure in most cases, unfortunately. The most widely used surgical procedure is the biliodigestive anastomosis. When biliodigestive anastomosis are used for treatment of a benign pathology with a high survival probability, particularly in stenosis or iatrogenic injuries of the main bile duct, the outcome is the loss of the sphincter of Oddi and an alteration in the normal physiology of the bile flow. This may produce complications, including cholestasis, cholangitis, stenosis and fistulae [25-27]. This investigation is developed within the conceptual framework of proposing a physiological solution, respecting the continuity of the biliary tree and the sphincter of Oddi for a stenosis or iatrogenic injury of the extrahepatic main bile duct. The object of our study is to compare the interposition of PTFE prosthesis with the creation of a biliodigestive Roux-en-Y bypass in the restoration of the bile flow.