Device profile of the Zephyr endobronchial valve in heterogenous emphysema: overview of its safety and efficacy

ABSTRACT

Introduction

Emphysema affects millions of people; the underlying pathophysiology is hyperinflation due to destruction of lung parenchyma. The mainstay of treatment is medical therapy however there are two surgical treatment strategies approved by the FDA to reduce lung hyperinflation. First being lung volume reduction surgery (LVRS), which carries higher risk of mortality versus bronchoscopic lung volume reduction (BLVR). BLVR has reduced peri-operative morbidity without compromising improvement in post-bronchodilator forced expiratory volume 1s (FEV1) and patient-reported outcomes. The added benefit of BLVR is that older adults who have end-stage emphysema who otherwise would not be appropriate surgical candidates for LVRS or transplant have an alternative treatment option.

Areas covered

This is a review paper focusing on Zephyr® endobronchial valves (EBV). Specifically, clinical outcomes of major trials, selection criteria, valve/deployment catheter features, description of procedure, discussing the Chartis™ Pulmonary Assessment System and StratX report, management of complications and discussing next steps in protocolizing post-EBV care.

Expert opinion

The expert opinion section focuses on outcomes from the LIBERATE Trial and 1-yr post-hoc analysis. Further 5-year follow-up post Zephyr® EBV placement along with protocolization post-EBV placement are needed to minimize adverse events and/or be able to manage, especially with high risk of pneumothorax (PTX).

KEYWORDS:

• BLVR
• Chartis pulmonary assessment system
• collateral ventilation
• patient & lobar selection
• StratX report
• Zephyr endobronchial valve

Article highlights

• Lung hyperinflation is the key target for treatment with bronchoscopic lung volume reduction. Prior to LIBERATE Trial Lung Volume Reduction Surgery (LVRS) was FDA approved for clinical use after the NETT Trial.

• There have been multiple Bronchoscopic Lung Volume Reduction (BLVR) clinical trials utilizing Zephyr® Endobronchial Valves (EBV) resulting in FDA approval, specifically in heterogenous emphysema: VENT, STELVIO, BeLieVer-HiFi, TRANSFORM and most recently LIBERATE.

• The significant patient and lobar selection criteria as per LIBERATE Trial that are currently being applied are: Targeted Lung Capacity > 100% of predicted, Residual Volume > 175% of predicted, smoking cessation for at least 4 months, controlled COPD (≤ 2 exacerbations requiring hospitalizations and ≤ 2 episodes of pneumonia in past year), destruction score based on < −910 Hounsfield units on HRCT, heterogenous emphysema based on ≥ 15% destruction score between the target and ipsilateral non-targeted lobe and lack of collateral ventilation.

• Fissure integrity indirectly assess the presence of collateral ventilation, which to date are assessed by visually scoring on HRCT (defined as ≥90%) versus the Chartis™ Pulmonary Assessment System and StratX Report which is a cloud-based quantitative CT.

• There are currently 4 sizes of Zephyr® Endobronchial Valves that are approved for clinical use depending on airway anatomy along with 3 different deployment catheters. Common adverse events are: PTX, post-obstructive PNA, acute COPD exacerbation (AECOPD), respiratory failure, persistent cough and lack of benefit due to misplaced/migrated valves.

• BLVR and LVRS are currently the only FDA approved techniques to reduce lung hyperinflation. There have been several other bronchoscopic modalities developed but not approved for clinical use, which include: PneumoRx® coil, AeriSeal, Bronchoscopic Thermal Vapour Ablation, and Exhale® Airway Bypass Stent.

Declaration of interest

G Criner has received grants from: NIH-NHLBI, PA-DOH, GSK, Boehringer-Ingelheim, Novartis, Astra Zeneca, Respironics, MedImmune, Pearl, PneumRx, Pulmonx, Broncus, Spiration, Olympus, Fisher-Paykel Healthcare, Chiesi, Gilead, Pfizer, Corvus, Lilly, Regeneron, Genetech, and Roche; has grants pending from: NIH-NHLBI, Nuvaira, and CSA Medical; and is a consultant for: Amirall, Astra Zeneca, Nuvaira, GSK, CSA Medical, PneumRX, BTG, Mereo, Broncus, Pulmonx, GSK,EOLO, and AERWAVE. S Verga has received consultation fees from Nuvaira. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

One peer reviewer has received consultant fees from Pulmonx and had stock options in the past. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper was not funded.