A system for treating a bifurcation includes first and second delivery catheters. The first catheter has a first shaft, a first expandable member adjacent the distal end of the first shaft, an auxiliary expandable member disposed under the first expandable member, and a first radially expandable stent disposed over both the first expandable member and the auxiliary expandable member. The second delivery catheter has a second shaft, and a second expandable member adjacent the distal end of the second shaft. A portion of the second catheter is disposed under a portion of the first stent, and a portion of the second delivery catheter passes through a side hole in the first stent. The first stent is crimped over the first and second catheters such that the first stent remains attached to the first and the second catheters during advancement of the catheters through a blood vessel.