A multi-cannula surgical instrument (1), having an inner cannula (3) movably disposed within an outer cannula (2), the inner cannula (3) having a blunt distal tip (3b), one or more first inner ducts (31) and one or more first flow-through orifices (32) arranged to allow one or more fluid flows therethrough, where the inner and the outer cannula (2, 3) at the proximal ends (2a, 3a) thereof are mounted onto a hub (4) that includes a biasing mechanism (43) coupled to the inner cannula (3) and arranged to bias the inner cannula (3) automatically from a retracted towards an advanced position in case of absence of resistance against the inner cannula (3), where the outer cannula (2) has one or more second flow-through orifices (22) that are in fluid communication with one or more second ducts (21) arranged between the outer and the inner cannula (2, 3), where the second flow-through orifices (22), the hub (4) and the second duct(s) (21) are configured to allow at least one fluid flow therethrough.