US Patent 11116943 Methods for accessing pedal veins

A launching catheter for targeting a second vessel from a first vessel includes a catheter including a proximal portion and a distal portion including a needle aperture and a flat rectangular radiopaque marker. The flat rectangular radiopaque marker disappears under fluoroscopy upon rotation to provide information about rotational alignment of the launching catheter. The launching catheter includes a needle configured to extend through the needle aperture. A method of aligning the catheter includes rotating the catheter in a first blood vessel until the marker has a thickness (e.g., minimal thickness) under fluoroscopy. The thickness indicates rotational alignment of the catheter.