A catheter having a proximal portion and a distal portion comprising: a first elongate tubular body； a second elongate tubular body； and an elongate member joining the first and second elongate bodies. The first elongate tubular body is disposed proximal and tandem to the second elongate tubular body, and the first and second tubular bodies are permanently disposed so that the first and second tubular bodies are not adjacent to each other. The catheter also comprises a third elongate tubular body, at least the proximal portion of the third elongate tubular body being disposed within the lumen of the first elongate tubular body, the third elongate tubular body being slidable within the lumen of the first elongate tubular body, and the distal portion of the third elongate tubular body being able to be disposed in the lumen of the second elongate tubular body.
