Novel devices and methods for implanting medical stents are provided. A novel apparatus, which may be in a first compressed position, may be inserted into the artery, such as by being positioned over a catheter. The apparatus may be expanded to a second position. In one embodiment, the apparatus is configured to expand away in two substantially opposing directions along a second axis away from the longitudinal axis. The second axis may be perpendicular to the longitudinal axis. The apparatus may include markers that are detectable to determine the orientation of the catheter or the apparatus and/or assist in the determination of the type or size of stent to utilize.