A multi lumen stent assembly (100) for deployment in a bifurcated vessel. This assembly is made of a self expandable main body component (200) and two lumen extensions (300) able to be inserted into one of the lumens of a double barrelled portion (208) of the main body component (200). The main body component (200) has a proximal end (201) configured to be placed toward the heart and a distal end (202). The main body component (200) has a main body portion (203) a concaved portion (206) and a transition portion (205). The main body portion (203) has a cylindrical lumen (204) of constant diameter. The concaved portion (206) has a double barrelled portion (208) having two lumens (211). A cross section of the transition portion (205) evolving from a circular shape to an elliptical shape towards the transition portion (205) a larger diameter of this shape being in a central plane (CP).
