Once these cells have attached and started to grow on the scaffold, it is ready to be implanted into the patient, and an operation is performed which occurs in two separate stages. The final stage of the operation involves removing the narrow section of voicebox or upper windpipe and implanting the scaffold to reconstruct it. Patients will be followed up for two years after this operation, with investigations such as CT scans, examination of the voicebox and windpipe with a flexible camera (bronchoscopy) and blood tests performed at specific times.