Devices and methods are disclosed for the direct visualization and localization of a target area within a body lumen through the optically clear walls of a graduated catheter. An elongated catheter has proximal and distal ends, an anchor, graduated markings, and outer and inner surfaces defining a catheter wall. The anchor establishes a secure relationship between the catheter and an anatomical feature. The graduated markings are disposed along a length of the catheter. The outer surface of the catheter wall is configured for contacting a body lumen and the inner surface of the catheter wall defines a main lumen disposed along a length of the elongated catheter. The catheter wall is transparent along a length to provide visualization of the graduated markings via a visualization tool positioned in the main lumen. In one embodiment, a catheter may have a substantially circular cross-section and include an arc-shaped transparent window.