A tracheostomy system includes an outer multi-layered tube, which can be expanded or allowed to contract as necessary in order to receive various sizes of cannula tubes. A dilator is used to initially insert the outer tracheostomy tube into the tracheostoma. After the initial installation dilator is removed, various sizes of dilators having a cannula mounted about them can be inserted into the outer tracheostomy tube. The multilayered tube will then expand in response to insertion of the various sizes of dilator cannula assembly being placed. When the dilator is removed the cannula tube will remain in place to maintain the desired diameter tracheostomy tube. This provides a means in which the diameter of the tube can be changed without having to actually remove and reinsert a different tube.