Cryospray Therapy for Benign Airway Stenosis

Inclusion Criteria: * Referral to interventional pulmonology or otorhinolaryngology or thoracic surgery for endoscopic management of suspected benign tracheal stenosis. * Significant tracheal stenosis defined by stenosis ≥ 50% of tracheal lumen assessed on chest CT or previous bronchoscopy * Able to provide informed consent. * Age \> 18 Exclusion Criteria: * Inability to provide informed consent * Pregnancy * Known or suspected malignant central airway stenosis * Patient has already been enrolled in this study. * Study subject has any disease or condition that interferes with safe completion of the study including: 1. Hypoxemia with need for supplemental oxygen ≥ 2L/min by nasal canula 2. Pneumothorax in the previous 12 months 3. Severe COPD (defined as a FEV1/FVC \< 70% and FEV1 \<30% predicted) and/or severe persistent asthma. 4. Hemodynamic instability with systolic blood pressure \<90 mmHg or heart rate \> 120 beats/min, unless deemed to be stable with these values by the attending physicians. 5. Compromised tissue where significant ulceration or mucosal break is evident in the ablation area or adjacent organs. 6. Significantly reduced tissue strength caused by prior procedure or pre-existing condition (e.g. PEG tube) 7. Significantly reduced elasticity of the ablation area (e.g. Marfan's Syndrome) * Prior complications with SCT (Spray cryotherapy) * Contraindication to rigid bronchoscopy * Significant tracheomalacia or alterations in cartilage integrity on CT (Computed Tomography) that would require stent placement or surgical referral. * Greater than 1 BCAS intervention, excluding cricotracheal (tracheal surgery) resection, within 6 months before enrollment. * Anatomical flow resistance (gas evacuation) where any procedure or anatomy proximal to the ablation site has significantly reduced or restricted the flow area of the lumen creating restriction where gas created from liquid nitrogen cannot adequately vent.