Disclosed herein is a cannula system 1 comprising a soft cannula 10 and a cannula unit for holding the soft cannula 10. The cannula unit comprises a compressing unit 20 and a body unit 30, wherein the body unit 30 contains a mounting structure 31 and a cavity 32 for holding a septum. The soft cannula 10 is threaded on the mounting structure 31. Furthermore, the compressing unit circumferentially surrounds the mounting structure 31 and at least parts of the body unit 30. The compressing unit 20 contains an internal material tension for exerting a compression force on the soft cannula and the mounting structure.
