Bronchial Cryo-Denervation for Severe Asthma: A Pilot Study

Introduction: Targeting the parasympathetic nervous system innervating the airway with pharmacologic products has been proved to improve the clinical outcomes of severe asthma. Bronchial cryo-denervation (BCD) is a novel non-pharmacologic treatment for severe asthma using an endobronchial cryo-balloon administered via bronchoscopy to denervate parasympathetic pulmonary nerves. Preclinical studies have demonstrated that BCD significantly disrupted vagal innervation in the lung. Methods: A total of 15 patients with severe asthma were enrolled in this prospective, single-center pilot study. Patients underwent bifurcated BCD treatment at a 30-day interval after baseline assessment. Follow-up through 12 months included assessment of adverse events, technical feasibility, and changes in pulmonary function; asthma control questionnaire-7 (ACQ-7); and asthma control test (ACT). Results: BCD was performed on all 15 severe asthma patients, with technical feasibility of 96.7%. There were no device-related and 2 procedure-related serious adverse events through 12 months, which resolved without sequelae. The most frequent nonserious procedure-related adverse event was increased cough in 60% (9 of 15) patients. Pulmonary function remained unchanged, and significant improvements from baseline ACQ-7 (mean, -1.19, p = 0.0032) and ACT (mean, 3.18, p = 0.0011) scores were observed since the first month's follow-up after a single lung airway treatment, with similar trends till the end of the 12-month follow-up. Conclusion: This study provides the first clinical evidence of the safety, feasibility, and initial efficacy of BCD in patients with severe asthma.