A system for delivering a medical device, such as an angioplasty balloon, includes two catheter shafts. The distal portion of a first shaft includes a first balloon and is narrower than the proximal portion. A second catheter shaft includes a second balloon and is connected to a medial portion of the first shaft. The second shaft includes a guidewire passageway which is in communication with the passageway of a third shaft that is removably connected to the first shaft. The distal tips of the first and second balloons are connected together to allow the system to be advanced to an anatomical site using a single guidewire. A second guidewire may be used to separate the distal ends of the balloons and to position the balloons at vascular bifurcation. A stent can be crimped onto the balloons such that inflation of the balloons implants the stent within the bifurcation.