Metered Cryospray (MCS), a radial spray which delivers programmed doses of liquid nitrogen (LN2) to the tracheobronchial airways, was safe and effective for improving multidimensional patient-reported outcomes in patients with chronic bronchitis in chronic obstructive pulmonary disease (COPD), according to study results published in European Respiratory Journal.

A total of 35 patients with chronic bronchitis in COPD (mean age, 67.2±7.0 years) were enrolled in this prospective, open-label study ( Identifier: NCT02483637). The study was conducted at sites in the United Kingdom, Netherlands, and Canada. Treatment included the use of a cryosurgical device that delivered metered doses of LN2 from a dewar to a catheter that emitted a radial spray. Phase A of the study, which was completed by 11 patients between March and August 2016, assessed the feasibility and safety of MCS treatment. An additional 24 patients underwent phase B, which consisted of 3 scheduled LN2 treatments delivered to the tracheobronchial tree.

Patients were assessed in person at 3 months, 6 months, 9 months, and 12 months following the final MCS treatment. The primary outcomes included feasibility (ie, completion of treatments), efficacy (ie, 3-month change in St. George’s Respiratory Questionnaire [SGRQ]), and safety (ie, incidence of adverse events [AEs]). Additional secondary outcomes included lung function, exercise capacity, and patient-reported outcomes.

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All 3 treatments were completed by 34 patients. Each session lasted 34.3±12.1 minutes and were separated by 4 to 6 weeks. Approximately 1800 doses of L2 were delivered. The investigators observed clinically meaningful improvements in patient-reported outcomes at 3 months, including significant changes in SGRQ (-6.4; 95% CI, -11.4 to -1.3; P =.01), COPD Assessment Test (CAT; -3.8; 95% CI, -6.4 to -1.3; P <.01), and Leicester Cough Questionnaire (LCQ; 21.6; 95% CI, 7.3-35.9; P <.01).

Changes in CAT were considered durable to 6 months (-3.4; 95% CI -5.9 to -0.9; P =.01). Additionally, durable changes were observed with SGRQ (-6.9; 95% CI, -13.0 to -0.9; P =.03) and LCQ (13.4; 95% CI, 2.1-24.6; P =.02) to 9 months. There were 14 serious AEs in 11 patients at 12 months. A total of 6 moderate and 8 severe AEs were reported at 12 months. There were 9 respiratory-related AEs, including 6 COPD exacerbations, 2 pneumonias, and 1 increased coughing.

Study limitations included the small sample size, the unblinded treatment, and the lack of a control group.

The researchers concluded that the efficacy and safety of MCS “will require confirmation by prospective randomized, sham-controlled trials.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Garner JL, Shaipanich T, Hartman JE, et al. A prospective safety and feasibility study of metered CryoSpray (MCS) for patients with chronic bronchitis in COPD [published online July 2, 2020]. Eur Respir J. doi:10.1183/13993003.00556-2020