A device (A) can be used to create a new channel to conduct fluid from a fluid-conducting catheter to a blood vessel without contact between the device or the catheter and the blood flow in the blood vessel. The device includes an outer and an inner tube-like part; in use, the tube-like parts are joined with essentially parallel axes, The outer tube-like part has a lengthwise slit along part of its length to let part of the blood vessel enter and, with the inner tube-like part, to form the new channel. The inner tube-like part is in part to be connected to the catheter. The device may be used to connect a CSF conducting catheter to the deep neck vein of a human. Also, an applicator device and a support instrument used to facilitate a surgical procedure of applying the device are described.