The present invention relates to a medical apparatus for closing an aperture (302), an incision, a puncture, a passage through tissue and/or a communication with a blood vessel or other body lumen (short: aperture) of a tissue (301) of a patient, the medical apparatus comprising a closing device holder (802), for releasably receiving one or more closing devices (600)； and a retracting unit (100) to come into contact with opposite sides of the aperture (302) and for retracting them and/or for spreading the aperture (302) causing it to change its shape into a slit or a slit-like or a more slit-like aperture (302) or to spread or to augment the dimension or diameter of the aperture (302) in at least one or in exactly one dimension of the aperture (302).
