Crosslink bio-adhesives for bronchoscopic lung volume reduction: current status and future direction

Lung-Mimetic Hydrofoam Sealant to Treat Pulmonary Air Leak

Pulmonary air leak is the most common complication of lung surgery, contributing to post-operative morbidity in up to 60% of patients; yet, there is no reliable treatment. Available surgical sealants do not match the demanding deformation mechanics of lung tissue; and therefore, fail to seal air leak. To address this therapeutic gap, a sealant with structural and mechanical similarity to subpleural lung is designed, developed, and systematically evaluated. This "lung-mimetic" sealant is a hydrofoam material that has alveolar-like porous ultrastructure, lung-like viscoelastic properties (adhesive, compressive, tensile), and lung extracellular matrix-derived signals (matrikines) to support tissue repair. In biocompatibility testing, the lung-mimetic sealant shows minimal cytotoxicity and immunogenicity in vitro. Human primary monocytes exposed to sealant matrikines in vitro upregulate key genes (MARCO, PDGFB, VEGF) known to correlate with pleural wound healing and tissue repair in vivo. In rat and swine models of pulmonary air leak, this lung-mimetic sealant rapidly seals air leak and restores baseline lung mechanics. Altogether, these data indicate that the lung-mimetic sealant can effectively seal pulmonary air leak and promote a favorable cellular response in vitro.

Surgical and bronchoscopic pulmonary function-improving procedures in lung emphysema

COPD is a highly prevalent, chronic and irreversible obstructive airway disease without curative treatment. Standard therapeutic strategies, both non-pharmacological and pharmacological, have only limited effects on lung function parameters of patients with severe disease. Despite optimal pharmacological treatment, many patients with severe COPD still have a high burden of dyspnoea and a poor quality of life. If these patients have severe lung emphysema, with hyperinflation as the driver of symptoms and exercise intolerance, lung volume reduction may be an effective treatment with a significant impact on lung function, exercise capacity and quality of life. Currently, different lung volume reduction approaches, both surgical and bronchoscopic, have shown encouraging results and have been implemented in COPD treatment recommendations. Nevertheless, choosing the optimal lung volume reduction strategy for an individual patient remains challenging. Moreover, there is still room for improving durability of effect and safety in all available procedures. Ongoing and innovative research is essential to push this field forwards. This review provides an overview of results and limitations of the current lung volume reduction options for patients with severe lung emphysema and hyperinflation.

From plugging air leaks to reducing lung volume: a review of the many uses of endobronchial valves

INTRODUCTION

One-way endobronchial valve treatment improves lung function, exercise capacity, and quality of live in patients with severe emphysema and hyperinflation. Other areas of therapeutic application include treatment of persistent air leak (PAL), giant emphysematous bullae, native lung hyperinflation, hemoptysis, and tuberculosis.

AREAS COVERED

In this review, we will assess the clinical evidence and safety of the different applications of one-way endobronchial valves (EBV).

EXPERT OPINION

There is solid clinical evidence for the use of one-way EBV for lung volume reduction in emphysema. Treatment with one-way EBV can be considered for the treatment of PAL. The application of one-way EBV for giant bullae, post lung transplant native lung hyperinflation, hemoptysis, and tuberculosis is under investigation and more research is required to investigate the efficacy and safety of these applications.

Bronchoscopic Management of COPD and Advances in Therapy

Chronic Obstructive Pulmonary Disease (COPD) is a highly prevalent and morbid disease marked by irreversible structural changes in the lungs. Bronchoscopic therapies have significantly expanded the treatment armamentarium for patients with persistent symptoms by reducing the physiologic detriments of hyperinflation in a less invasive fashion than surgical lung volume reduction. The spectrum of bronchoscopic techniques to reduce hyperinflation includes endobronchial valves, coils, thermal ablation, and biologic sealants. Other therapies focus on reducing parasympathetic tone and mucus hypersecretion and include targeted lung denervation, bronchial rheoplasty, and cryospray techniques. In this article, we will review the variety of techniques for bronchoscopic lung volume reduction, both established and investigational, along with their respective benefits and complications and will briefly review other investigational therapies for COPD.