Disclosed is a medical an insertion aid for surgical instruments and / or optical systems with a shank 1 which forms a feed channel 6, on the inner wall at least one in the longitudinal direction of the extending or longitudinally oriented groove 14 is shaped. In addition or alternatively, a medical insertion aid is disclosed, which in its distal end portion (the axial central section, preferably in the distal end area) has a radially outwardly extending, preferably of closed circumferential fluid-flow-blocking edge has. This forms more preferably at least one axially opening circular trough or groove with the opening direction to the distal end of the proximal end and / or.
