The invention provides a stoma-creating apparatus for creating a stoma in a subject. The apparatus comprises first and second members, and one or more dilation means provided on the first and/or second member. In use, upon respective movement of the first and second members, the stoma-creating apparatus is arranged to move between a first closed configuration in which the one or more dilation means is substantially closed, and a second open configuration in which the one or more dilation means is substantially dilated, thereby creating a stoma in the subject. The invention is particularly concerned with creating stomas which hold a tracheostomy tube in position on the trachea of a patient undergoing a tracheostomy, or for securing a valve or other medical device in position adjacent a patient's pneumothorax.