Bronchoscopic spray cryotherapy: Assessment of safety and depth of airway injury

Abstract

Traditional approaches to managing occluded airways include surgery, mechanical debulking, brachytherapy, stents, photodynamic therapy, and thermal modalities, such as electrocautery, laser, argon plasma coagulation, and cryotherapy. Although cryotherapy with cryoprobes has been used safely for over a decade in airways management, it is often tedious and time-consuming because of surface area limitations of the probes, which must be inserted into or come in contact with the surface of the targeted lesion. Newer cryotherapy devices obviate the need for contact with the target tissue. Reports of promising results from use of low-pressure spray cryotherapy for ablation of esophageal lesions 1-2 have led to the experience reported here, in which spray cryotherapy with low-pressure liquid nitrogen was used for the first time to treat human airways.

Feasibility of spray cryotherapy and balloon dilation for non-malignant strictures of the airway

“…Table 1 demonstrates the number of repeat cryotherapy treatment sessions required related to initial stricture severity. The mean follow-up was 8.2 months (range [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and was available in 33/35 patients. There were no perioperative deaths, but complications occurred after two procedures and included the need for a tracheostomy in one patient, and pneumothorax in another.…”

“…Future investigation should ideally be undertaken comparing this approach to other common endoscopic approaches, such as dilation or stenting with silastic stents, with careful classification of stricture severity/type to determine success rates with each therapy. However, an important advantage with SC may be that this modality will not adversely affect future intervention (in particular, surgery) because of the favorable wound response [3,4] although, this is speculative.…”

“…Spray cryotherapy (SC) is a new thermal energy platform that has been used extensively in the gastrointestinal tract and more recently reported in the airway [1][2][3]. Because the integrity of the extracellular matrix remains largely intact at the current dosimetries used with SC [3], and because an intact stroma provides the structural framework for appropriate wound repair, a fundamental shift in the wound response results in a more normative healing process [17,18].…”

“…Because the integrity of the extracellular matrix remains largely intact at the current dosimetries used with SC [3], and because an intact stroma provides the structural framework for appropriate wound repair, a fundamental shift in the wound response results in a more normative healing process [17,18]. This has been observed in different tissues treated with this technology.…”

“…This has been observed in different tissues treated with this technology. Following this type of thermal injury, there is felt to be a more favorable wound response with less long-term scarring, which may be beneficial for patients with benign airway strictures [3,4]. Healing with less fibrosis may allow a reduced number of re-interventions as well as prolong the symptom-free time between interventions.…”