In one instance, a catheter for replacing or adding a guide wire into a patient is provided. The catheter includes a first rapid exchange lumen, a second rapid exchange lumen, and a releasable wire-securing device. A second guide wire is placed in the second rapid exchange lumen and secured into position. The catheter is then advanced along the first guide wire until in position, and then the second guide wire is released from the wire-securing device and advanced into the desired position. The catheter is then removed. Other catheters and methods are also disclosed.