The present invention relates to a method and a device for avoiding that any of at least one first or at least one second access device (20, 30) is unintentionally withdrawn from a vessel (11). According to the present invention this is achieved by inserting the first access device in a first direction in the vessel, inserting the second access device in a second direction in the vessel, the second direction being different from the first direction and interconnecting the first and the second access device by providing a fixed length of an interconnecting device (50).
