A catheter in accordance with one embodiment of the invention includes a first end, a second end, and a body, which comprises one or more segments, disposed between said first end and said second end, wherein at least one of the one or more segments has a first section and a second section, wherein the first section has a first tapered surface with a diameter increasing from a first edge to a ridge and a second section has a second tapered surface with a diameter decreasing from the ridge to a second edge, and wherein a first volume enclosed between said first tapered surface in the first section and an imaginary cylinder circumscribing the ridge is smaller than a second volume enclosed between the second tapered surface in the second section and the imaginary cylinder.
