This study aims to test a new groundbreaking treatment for narrowing of the voicebox and upper windpipe, which can be due to injury, inflammatory disease or cancer treatment. Narrowing of the voicebox or upper windpipe can leave patients dependant on a tracheostomy tube to breath through (a tube or hole in the neck), which can require a high level of care with regular hospital visits and can lead to recurrent chest infections. Regular surgical procedures may be necessary to widen the airway. Speaking may be very difficult or not even possible, breathing is usually a struggle and swallowing can also be affected. Patients feel very tired all the time.