Metered Cryospray™: a novel uniform, controlled, and consistent in vivo application of liquid nitrogen cryogenic spray

Challenges in clinical practice, biological mechanism and prospects of physical ablation therapy for COPD

Chronic obstructive pulmonary disease (COPD) is projected to become the third leading cause of death globally by 2030. Despite the limited treatment options available for advanced COPD, which are mostly restricted to costly lung transplants, physical ablation therapy offers promising alternatives. This technique focuses on ablating lesioned airway epithelium, reducing secretions and obstructions, and promoting normal epithelial regeneration, demonstrating significant therapeutic potential. Physical ablation therapy primarily involves thermal steam ablation, cryoablation, targeted lung denervation, and high-voltage pulsed electric field ablation. These methods help transform the hypersecretory phenotype, alleviate airway inflammation, and decrease the volume of emphysematous lung segments by targeting goblet cells and damaged lung areas. Compared to traditional treatments, endoscopic physical ablation offers fewer injuries, quicker recovery, and enhanced safety. However, its application in COPD remains limited due to inconsistent clinical outcomes, a lack of well-understood mechanisms, and the absence of standardized guidelines. This review begins by exploring the development of these ablation techniques and their current clinical uses in COPD treatment. It then delves into the therapeutic effects reported in recent clinical studies and discusses the underlying mechanisms. Finally, the review assesses the future prospects and challenges of employing ablation technology in COPD clinical practice, aiming to provide a practical reference and a theoretical basis for its use and inspire further research.

Current status of interventional therapy for pulmonary emphysema with bronchoscopy

Pulmonary emphysema is one of phenotypes of lung disease that can progress to chronic obstructive pulmonary disease (COPD). The pathogenesis is unknown, which may be closely related to smoking, infection, gene mutation, and air pollution. Pathological features of emphysema include the decreased airway elasticity at the distal end of the bronchioles and over-hyperinflation. As the incidence and mortality of COPD increase, emphysema has become the focus of research. The efficacy of drugs for COPD is limited, and currently the treatment of emphysema mainly depends on surgery. Since the concept of lung volume reduction surgery was proposed in the 1990s, many studies have confirmed improvement of lung function and exercise capacity, but the large wound, high mortality, and high cost have reduced its benefits. Lung volume reduction surgery with bronchoscopy technology, including valves, coils, sclerosants, vapor thermal ablation, etc., has the advantages of minimal invasive and decreased mortality under the basis of effectiveness. This article aims to review the current status of interventional therapy for pulmonary emphysema with bronchoscopy, compare and summarize the characteristics and applicable populations of interventional therapy, and provide theoretical support for patients' early referral and clinicians' decision-making.

A prospective safety and feasibility study of metered cryospray for patients with chronic bronchitis in COPD

Background

No currently approved intervention counteracts airway metaplasia and mucus hypersecretion of chronic bronchitis in COPD. However, metered cryospray (MCS) delivering liquid nitrogen to the tracheobronchial airways ablates abnormal epithelium and facilitates healthy mucosal regeneration. The objective of this study was to evaluate the feasibility, efficacy and safety of MCS in chronic bronchitis.

Methods

Patients with a forced expiratory volume in 1 s of 30–80% predicted who were taking optimal medication were recruited. Primary outcomes were feasibility (completion of treatments), efficacy (3-month change in St George's Respiratory Questionnaire (SGRQ)) and safety (incidence of adverse events). Secondary outcomes were lung function, exercise capacity and additional patient-reported outcomes.

Results

35 patients, 19 male/16 female, aged 47–76 years, Global Initiative for Chronic Obstructive Lung Disease grade I (n=3), II (n=10) and III (n=22), underwent staggered liquid nitrogen treatments to the tracheobronchial tree. 34 patients completed three treatments, each lasting 34.3±12.1 min, separated by 4–6 weeks; one withdrew after the first treatment. ∼1800 doses of MCS were delivered. Clinically meaningful improvements in patient-reported outcomes were observed at 3 months: change in SGRQ −6.4 (95% CI −11.4 to −1.3; p=0.01), COPD Assessment Test (CAT) −3.8 (95% CI −6.4 to −1.3; p<0.01) and Leicester Cough Questionnaire (LCQ) 21.6 (95% CI 7.3 to 35.9; p<0.01). Changes in CAT were durable to 6 months (−3.4, 95% CI −5.9 to −0.9; p=0.01); changes in SGRQ and LCQ were durable to 9 months (−6.9, 95% CI −13.0 to −0.9; p=0.03 and 13.4, 95% CI 2.1 to 24.6; p=0.02, respectively. At 12 months, 14 serious adverse events were recorded in 11 (31.4%) subjects; six (43%) moderate and eight (57%) severe. Nine were respiratory-related: six exacerbations of COPD, two pneumonias and one case of increased coughing; all recovered without sequelae. None were serious device- or procedure-related adverse events.

Conclusion

MCS is safe, feasible and associated with clinically meaningful improvements in multidimensional patient-reported outcomes.

RejuvenAir system treatment for individuals with chronic bronchitis in COPD is safe, feasible, well tolerated, and resulted in clinically meaningful improvements in multidimensional measures of cough, sputum production, breathlessness and quality of lifehttps://bit.ly/30KBfPs