A Study to Assess the Safety, Tolerability and Potential Efficacy of a Tracheal Replacement Consisting of a Tissue-engineered Tracheal Scaffold With Seeded Mesenchymal Cells

Inclusion Criteria: * Male or female subjects 18 years or older (all subjects must provide written informed consent) * Stent or tracheostomy dependent diagnosis of tracheal stenosis or tracheomalacia (Cotton-Myers grade 2 or more) * Subjects in the above categories for whom further conventional therapies are no longer adequate Exclusion Criteria: * Pregnancy * Subjects unable to provide informed consent * Prior tracheal transplant * No viable bone marrow cells within the screening period * Subjects who have conventional treatment options still available that may have additive impact * Subject diagnosed or treated for a malignancy within 1 year of study entry or who have previously been diagnosed with a malignancy and have any radiographic or biochemical biomarker evidence of malignancy. Subjects with completely resected basal cell carcinoma or squamous cell carcinoma of the skin or in situ malignancy are not excluded * Subject with active inflammatory or infectious conditions such as polychondritis, granulomatosis with polyangiitis ('Wegener's'), sarcoidosis or tuberculosis * Co-morbid moderate or severe chronic obstructive pulmonary disease (COPD) as defined in Global Initiative for COPD, 2011 2, that is unrelated to tracheal stenosis or malacia * Subjects with known presence of human immunodeficiency virus (HIV) antibody, Hepatitis B surface antigen (HbsAG) or Hepatitis C antibody * Subject with clinically relevant or recent (within 2 years) history of substance abuse, i…