A system for inserting a tracheal cannula into a tracheostomy, comprises: a tracheal cannula 5； and an insertion aid 1 that includes a handle 2, a curved body 3 and a tip 4. A bayonet closure system 6, provides a releasably coupling between the insertion aid 1 and the tracheal cannula 5, with the bayonet system 6 comprising a bayonet ring 10 connected to insertion aid 1 and a bayonet attachment 11 connected to tracheal cannula 5. Bayonet ring 10 may include three or four closure arrangements 14 for making a form-fitting connection with three or four contours 16 of the bayonet attachment 11. Bayonet ring 10 may comprise a lug 15, where bayonet ring 10 is mounted on the insertion aid 1 allowing rotation of bayonet ring 10 about the longitudinal axis of the insertion aid 1 through lug 15 engaging in a groove 13, thereby securing against displacement of bayonet ring 10 along the longitudinal axis of the insertion aid 1. At a patient facing end of tracheal cannula 5, there may be a transitional region 12, where the tracheal cannula wall thickness decreases to provide an atraumatic transition for insertion of the cannula 5 into a tracheostomy.
