A catheter (100, 200) for insertion into a human and/or animal hollow organ, comprising a catheter shaft (110, 210) with a lumen (120, 220), which opens into a front opening at a distal end (112, 212) of the catheter shaft (110, 210), wherein the catheter shaft (110, 210) has at least a first lateral opening (130, 230a) that is at a distance from the distal end (112, 212) and opens into the lumen (120, 220), is distinguished by virtue of the fact that there is at least a first insertion device (140, 240a), arranged on an external side (114, 214) of the catheter shaft (110, 210) in a region of the first lateral opening (130, 230a), for a wire-like element (300, 400, 500) that should be inserted into the first lateral opening (130, 230a) from the outside.
