An introducer assembly (10) includes a distal sheath (20) and a proximal sheath (22). A splitting element (50) is located at a proximal end (38) of the distal sheath (20) and is arranged to split the distal sheath (20) in a distal direction, so as to deploy first a branch element (32) of a medical device (30) and thereafter the distal end of the medical device (30). The proximal sheath (22) can then be retracted to release the proximal end of the medical device (30). Deployment of the medical device from the branch element (32) first enables accurate positioning of the branch element (32) prior to deployment of the main body portion (40) of the medical device.