State of the art and operative technique for spray cryotherapy for central airway obstruction (CAO)—a narrative review

Background and Objective: Recent years have seen a paradigm shift from open resection to endoluminal therapies for central airway obstruction (CAO). Historically, heat-based modalities, which have been the most common treatment tools, have raised concern for additional scarring and disease progression due to their disruption of the underlying extracellular matrix (ECM) and protein denaturation. In contrast, spray cryotherapy (SCT) preserves ECM, thus allowing for a more favorable wound healing response and scar remodeling. Herein we provide a review of current literature on the developments in SCT for CAO. Methods: We conducted an electronic-based literature search on PubMed and Google Scholar databases of English language publications to identify data on utility of SCT for CAO. We also manually searched the reference lists of relevant studies. Key Content and Findings: SCT is an advanced bronchoscopic technique that maintains the integrity of underlying ECM allowing for controlled wound healing, scar remodeling and tissue regeneration. Several recent studies have shown good outcomes with this therapy. Our group has had significant success in this area and we have demonstrated the efficacy of SCT in patients with recalcitrant stenosis who have shown a poor response to conventional therapies. We also provide a description of our technique using SCT for CAO. Conclusions: Studies have shown SCT to be a safe modality that offers good long-term outcomes in patients with CAO. There is a need for additional trials and studies to further demonstrate the efficacy of SCT.