Cryospray Therapy for Benign Airway Stenosis

Study Overview
=================
Brief Summary
-----------------
This is a clinical evaluation to assess the effectiveness of cryospray therapy used in addition to current standard of care endoscopic therapies in preventing short term recurrent airway stenosis with a multicentric outcome evaluation. The investigators hypothesize that the addition of SCT to standard endoscopic treatment of benign airway stenosis will result in decreased stenosis recurrence at 6 months as estimated by quantitative radiologic assessment of the stenotic volume.

Detailed Description
-----------------
Spray cryo treatment of tracheal stenosis has the potential for long-lasting endoscopic management of BCAS and is used as part of routine clinical care by many physicians, but there is a relative paucity of peer-reviewed data, and no randomized controlled trial has been performed. Thus, the study could potentially show that the use of spray cryo therapy could allow patients to undergo fewer procedures to treat this condition, or lengthen the amount of time required in between these procedures, or play a role in the resolution of this condition.

Official Title
-----------------
Cryospray Therapy for Benign Airway Stenosis: a Pilot Study (Pilot-CRYOSTASIS)

Conditions
-----------------
Stenosis Trachea

Intervention / Treatment
-----------------
* Device: The truFreeze Spray Cryotherapy
* Device: Ballon dilation
* Device: Radial Incision


Participation Criteria
=================
Eligibility Criteria
-----------------
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: Hypoxemia with need for supplemental oxygen ≥ 2L/min by nasal canula Pneumothorax in the previous 12 months Severe COPD (defined as a FEV1/FVC < 70% and FEV1 <30% predicted) and/or severe persistent asthma. 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. Compromised tissue where significant ulceration or mucosal break is evident in the ablation area or adjacent organs. Significantly reduced tissue strength caused by prior procedure or pre-existing condition (e.g. PEG tube) 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.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants will be randomly allocated in a 1:1 fashion to intervention standard of care (SOC) + SCT and control (SOC) groups. Participants will be blinded to the use of SCT to prevent knowledge of their group assignment from biasing their subjective assessments. Adjudicators in the primary outcome measurements (quantitative CT) will be blinded to group assignment as well.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention<br>Bronchoscopic balloon dilation with radial cuts & truFreeze spray cryotherapy | Device: The truFreeze Spray Cryotherapy<br>* A novel FDA cleared technique that allows for liquid nitrogen (LN2) to be delivered in a metered fashion via a catheter through a flexible bronchoscope.<br>Device: Ballon dilation<br>* An endoscopic balloon that is inflated with water to pressures between 45 and 131 psi (3-9 atm) using a syringe and pressure manometer.<br>Device: Radial Incision<br>* Carbon dioxide (CO2) laser or Monopolar electrocautery knife<br>|
| Active Comparator: Standard of care<br>Bronchoscopic balloon dilation with radial cuts | Device: Ballon dilation<br>* An endoscopic balloon that is inflated with water to pressures between 45 and 131 psi (3-9 atm) using a syringe and pressure manometer.<br>Device: Radial Incision<br>* Carbon dioxide (CO2) laser or Monopolar electrocautery knife<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Degree of re-stenosis | The degree of re-stenosis at 6 months expressed as the percentage of airway lumen volume within the stenotic segment at 6 months compared to personal best patency volume on CT scan performed within five weeks of the study intervention. | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Peak Expiratory Flow (PEF) | Evidence supports the use of PEF as a simple, efficient, and accessible way of monitoring progression of tracheal stenosis. PEF has previously been captured in clinical encounters as component of the decision-making algorithm for surgical intervention in tracheal stenosis patients. Mobile Device Software 'App' can robustly capture longitudinal patient reported outcome measures. A previously developed mobile device software 'Airflo' for tracking patient-generated health data and has proven the ability to successfully implement this software. | Continous for 6 months | 
| Clinical Chronic Obstructive Pulmonary Disease Questionnaire (CCQ) | The CCQ has been used as a validated quality of life measure in laryngotracheal stenosis. The investigators will send surveys out to patients at set time intervals to assess symptom improvement pre- and post-intervention. The questions are divided into three areas or domains. Symptoms 1, 2, 5, 6; Functional state 7, 8, 9, 10; Mental state 3 and 4. All items are equally weighted by adding score of ten items and dividing by the number ten. The score varies between 0 (very good health status) to 6 (extremely poor health status). | 2 weeks before procedure, 2 weeks after the procedure, the 3 month study mark, the 6 months study mark, | 
| Incidence of complications between groups | Incidence of complications (hypoxemia, bleeding, pneumothorax rate, barotrauma). | Continous for 6 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
cryospray therapy, benign airway stenosis