A catheter having a proximal portion and a distal portion comprising: a first elongate tubular body having a proximal portion, a distal portion, a proximal end having a proximal opening, a distal end having a distal opening, and a lumen extending between the proximal opening and the distal opening; a second elongate tubular body having a proximal portion, a distal portion, a proximal end having a proximal opening, a distal end having a distal opening, and a lumen extending between the proximal opening and the distal opening, wherein the proximal end of the second elongate tubular body defines an interior diameter larger than an exterior diameter defined by the first elongate tubular body and wherein the interior diameter of the second elongate tubular body decreases from the proximal end to the distal end of the second elongate tubular body; and an elongate member joining the first and second elongate tubular bodies, the first elongate tubular body being disposed proximal and tandem to the second elongate tubular body, and the first and second elongate tubular bodies being permanently disposed so that the first and second elongate tubular bodies are not adjacent to each other, further comprising a third elongate tubular body having a proximal portion, a distal portion, a proximal end having a proximal opening, a distal end having a distal opening, and a lumen extending between the proximal opening and the distal opening, wherein each of the first, second and third elongate tubular bodies (26, 28, 30) are configured to receive a medical device within their lumens, 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 wherein the third elongate tubular body is configured to move between: a proximal position in which the distal end of the third elongate tubular body is disposed proximal of the proximal end of the second elongate tubular body; and a distal position in which the distal end of the third elongate tubular body is disposed within the lumen of the second elongate tubular body, wherein the proximal end of the third elongate tubular body is maintained within the lumen of the first elongate tubular body when the third elongate tubular body is in the proximal position and when the third elongate tubular body is in the distal position. a first elongate tubular body having a proximal portion, a distal portion, a proximal end having a proximal opening, a distal end having a distal opening, and a lumen extending between the proximal opening and the distal opening; a second elongate tubular body having a proximal portion, a distal portion, a proximal end having a proximal opening, a distal end having a distal opening, and a lumen extending between the proximal opening and the distal opening, wherein the proximal end of the second elongate tubular body defines an interior diameter larger than an exterior diameter defined by the first elongate tubular body and wherein the interior diameter of the second elongate tubular body decreases from the proximal end to the distal end of the second elongate tubular body; and an elongate member joining the first and second elongate tubular bodies, the first elongate tubular body being disposed proximal and tandem to the second elongate tubular body, and the first and second elongate tubular bodies being permanently disposed so that the first and second elongate tubular bodies are not adjacent to each other, further comprising a third elongate tubular body having a proximal portion, a distal portion, a proximal end having a proximal opening, a distal end having a distal opening, and a lumen extending between the proximal opening and the distal opening, wherein each of the first, second and third elongate tubular bodies (26, 28, 30) are configured to receive a medical device within their lumens, 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 wherein the third elongate tubular body is configured to move between: a proximal position in which the distal end of the third elongate tubular body is disposed proximal of the proximal end of the second elongate tubular body; and a distal position in which the distal end of the third elongate tubular body is disposed within the lumen of the second elongate tubular body, wherein the proximal end of the third elongate tubular body is maintained within the lumen of the first elongate tubular body when the third elongate tubular body is in the proximal position and when the third elongate tubular body is in the distal position. a proximal position in which the distal end of the third elongate tubular body is disposed proximal of the proximal end of the second elongate tubular body; and a distal position in which the distal end of the third elongate tubular body is disposed within the lumen of the second elongate tubular body, wherein the proximal end of the third elongate tubular body is maintained within the lumen of the first elongate tubular body when the third elongate tubular body is in the proximal position and when the third elongate tubular body is in the distal position.