A drive device in a medical device for driving a wire through a guide tube from a first position with an end of the wire outside an animal body to a second position in which the end is inside the animal body. The drive device comprises first and second elements rotatable relative to each other. The first and second elements each have contact surfaces, that in each rotational position of the first and second elements relative to each other are in contact with each other in a contact area along a common contact plane. A storage space going about the axis is provided for the wire in the first element. The storage space is open along a length of it to the contact surface of the first element. The second element comprises a channel for the wire and is open to the contact plane.