A catheter having a multilumenal tube surrounded by a slotted hypotube is provided. The catheter has a tube holder that houses the multilumenal tubing and slidably engages the hypotube, and has internal passages configured to receive one of more tubes from the multilumenal tube. The multilumenal tubing separates into one or more tubings, each comprising a lumen, such that the tubings exit the tube holder at different locations. The slotted hypotube slidably engages a key in the tube holder that prevents the multilumenal tubing from rotating relative to the tube holder and the one of more tubings that separate from the multilumenal tubing. Advantages provided by the slotted hypotube/tube holder assembly are described.