A stent delivery system (10) for positioning at a vessel bifurcation, the delivery system comprising:a catheter (12,112) including a main vessel guidewire lumen that is adapted to receive a main vessel guidewire (21,121)a stent (125) being disposed over the catheter, the stent including a side opening for positioning at an ostium of the vessel bifurcationthree catheter markers positioned on the cathetera flexible side sheath positioned adjacent the catheter, the flexible side sheath including a branch vessel guidewire lumen that is adapted to receive a branch vessel guidewire, wherein a distal end of the flexible side sheath projects outwardly through the side opening of the stent andtwo flexible side sheath markers.
