The device has a fixation unit including a fixation piece (4) integrated into a support element. The piece is made of elastically deformable material, and includes a tubular portion having a longitudinal opening (7) such that that the portion is fitted onto a determined area (2c) of an introduction needle (2) by applying force to the piece along the opening perpendicular or oblique to the needle. A set of annular faces (11, 12) of the piece and another set of annular faces (9, 10) of the needle are cooperated with each other to prevent sliding of the piece interlocked on the needle area.
