A guiding aid for an instrument to be advanced within a vascular system, particularly the human vascular system, comprising a flexible shapeable shaft comprising a first bent section having a first curvature and at least one further bent section, wherein the bent sections of the shaft have the same sign of curvature and are located substantially within the same plane. Such a guiding aid may be pre-formed by the manufacturer such that the guiding aid may be introduced into vascular branchings both from large lumen and small lumen vessels by a physician manipulating the instrument from its proximal end.
