A stent assembly comprises a proximal stent and a distal stent. Each stent has a tubular body defining a stent lumen and a circumference. A proximal flap extends from the distal end of the proximal stent and a distal flap extends from the proximal end of the distal stent. Each flap defines only a portion of the circumference. In an expanded state the proximal flap and the distal flap form a side branch support having a side branch support lumen. The side branch support lumen is in fluid communication with the stent lumen and has a longitudinal axis different from that of the stent lumen.