A device for introduction into a vessel including a main elongated element having a main elongated element proximal end and a main elongated element distal end, a balloon positioned at the main elongated element distal end, and a core wire attached to the device at a core wire attachment point and including an internal core wire portion positioned in the main elongated element and an external core wire portion positioned distally with respect to the internal core wire portion and positioned in parallel relation and external to the balloon.
