Endoscopic Lung Volume Reduction

Abstract

Chronic obstructive pulmonary disease (COPD) is a category of diseases characterized by chronic airflow obstruction and hyperinflation. The GOLD committee and the American Thoracic Society/European Respiratory Society have published detailed, evidence-based reviews of management approaches, providing stepped-care algorithms for pharmacologic and nonpharmacologic therapy. Over the past several decades, much effort was spent in designing additional nonpharmacologic approaches to ameliorate symptoms in these patients. Three endoscopic lung volume reduction principles have shown promise and reached later-stage clinical trials in patients with heterogeneous emphysematous diseases. These include so-called blocking devices (valves), nonblocking devices (coils) and irreversible nonblocking techniques (bronchoscopic thermal vapor ablation, polymeric lung volume reduction) designed to collapse and remodel hyperinflated lung. For homogeneous diseases the formation of airway bypass tracts designed to facilitate emptying of damaged lung regions with long expiratory times is being investigated.

Endoscopic Lung Volume Reduction

“…The first and most known method of endoscopic lung volume reduction is the implantation of valves in targeted most destroyed lung compartments in patients with heterogeneous emphysema [11]. These blocking devices allow the air to be expelled during expiration but prevent the air entering the target lobe during inspiration and so facilitating atelectasis to achieve lung volume reduction.…”

Chronic Obstructive Pulmonary Disease: Emphysema Revisited

“…Bronchoscopic LVR aims to achieve the same goals as LVRS: improve physiologic mechanics of the chest wall and diaphragm, restore ventilation-perfusion matching, and improve expiratory airflow. The method by which this is achieved is through the use of a bronchoscope to deploy one-way valves, administer sealants, or apply thermal ablation to exclude diseased portions of the lung [60][61][62]. It is important to note that these techniques have not been approved by the Food and Drug Administration (FDA) for the treatment of severe emphysema and are currently utilized on experimental basis only.…”

“…One-way valves allow air and mucus to escape from the excluded portion of lung yet concomitantly excluding that portion of the lung from normal physiological function. [61] Multiple valve designs have been tested, the largest on which was the Endobronchial Valve for Emphysema Palliation Trial (Figure 4) (VENT) [63][64] There was significant improvement in dyspnea, exercise capacity, and quality of life but not as significant as that which is seen in LVRS. [64].…”

Selected clinical highlights from the 2010 ERS Congress in Barcelona

“…Currently, the most successful method of endoscopic lung volume reduction in patients with heterogeneous emphysema is the implantation of endobronchial valves (Zephyr1; Pulmonx Inc., Palo Alto, CA, USA) or intrabronchial valves (Spiration1; Olympus America Inc., Center Valley, PA, USA), targeting the lung compartments with the most advanced lesions [1]. These blocking devices vary in shape but both consist of a one-way valve that allows the air to exit during expiration but not to enter during inspiration, therefore causing lobar or segmental atelectasis and consequent volume reduction.…”