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

Abstract

Benign airway strictures can be complex and challenging to manage. Although resection is preferred, this is not always feasible, and hence, endoscopic therapies are often performed. However, endoscopic therapies can be problematic, with granulation tissue and fibrosis leading to early failure. Spray cryotherapy (SC) is a new approach that may modulate the healing response leading to less fibrosis and decrease the need or the duration of time to intervention. We report the initial results of SC for benign airway strictures. Over a 22-month period, 35 patients underwent SC. Median age was 51(18-81) years. Prior therapy had been undertaken in 14 (41.2%) of patients. Stricture etiology included post intubation (n=5), prior tracheostomy (n=6), radiation induced (n=2), prior surgery (n=3), other causes (n=12), or unknown etiology (n=7). Airway narrowing was graded as follows: 1=0-25%, 2=26-50%, 3=51-75%, and 4=76-100%. For the purpose of analysis, this was treated as a continuous variable. The usual treatment algorithm consisted of ×3-4 SC cycles, followed by balloon dilation, and then by additional SC cycles. Stricture locations were subglottic (n=18), tracheal (n=9), and bronchial (n=8). Seventeen (49%) patients required additional SC therapy, resulting in a total of 63 SC treatment sessions. Only two (3.2%) complications occurred and these included pneumothorax (n=1) and intra-operative tracheostomy (n=1). Mean follow-up was available in 33/35 patients at a mean of 8.2 (1-19) months. Twelve (of 33) patients (36.4%) were asymptomatic, 16/33 (48.5%) were improved, 4/33(12.1%) had no improvement or were worse, and 1/33(3%) patient died from an unrelated cancer. On follow-up bronchoscopy, performed in 28 patients, airway narrowing improved significantly from 3.5 to 2.03 (p<0.001). Initial experience with SC for benign airway strictures suggests that this can be used safely. This is effective in improving symptoms and reducing the severity of airway narrowing. Re-intervention is still required. Further study should be undertaken to determine factors that may be associated with success or failure as well as the relative efficacy of SC compared with other endoscopic therapies.