Needles are provided including elongate tubular cannulas having proximal portions, distal portions, and cannula walls defining cannula lumens. A distal portion of an elongate tubular cannula may include a distal end, one or more apertures disposed through, and along a first length of, the cannula wall in a pattern enhancing flexibility relative to a second length of the cannula wall lacking the apertures, and a sealing member disposed on the apertures. The apertures impart enhanced flexibility to the needle for navigating through tortuous pathways.
