A catheter with an asymmetric cross-section is disclosed. The catheter comprises a flexible hollow tube with two bores, a large one that includes the longitudinal axis of the tube, and a small one disposed spirally about the first bore. In preferred embodiments of the invention, the tube is characterized by a transverse cross section in which the first central bore is meniscus-shaped and the second bore is disposed opposite the concave side of the meniscus. The catheter has improved pushability, crossability, trackability, and flexibility relative to catheters known in the art.
