Endoscopic treatment of emphysema

The aim of (partial) lung volume reduction in emphysema patients is “to make the lung smaller”, stated Prof. Felix Herth (UniversitätsKlinikum Heidelberg, Germany) at the beginning of his lecture. Because of the presence of hyperinflated areas in these patients, volume reduction improves breathing mechanics, exercise capacity, and quality of life, and hopefully decreases mortality. For lung volume reduction, five different techniques are available: endoscopic volume reduction surgery (EVRS), valves, coils, steam, and glue.

Evidence for lung volume reduction

Since 2002, multiple studies about lung volume reduction have been published. The most recent one was the LIBERATE study, evaluating the effectiveness of the Zephyr® Endobronchial Valve (EBV®) vs standard of care. This device provided clinically meaningful benefits in lung function, i.e. change in FEV₁ ≥15% of 47.7% of patients in the EBV group vs 16.8% in the standard of care group (P<0.001; see Figure 1). Furthermore, exercise tolerance, dyspnoea, and quality of life improved during the follow-up period of ≥1 year (see Table 1). The safety profile in patients with little or no collateral ventilation in the target lobe was acceptable. Pneumothorax was the most common serious AE in the post-intervention period of 45 days, occurring in 26.6% of EBV subjects [1].

Figure 1: Percentage of patients with FEV₁ change of ≥15% after 12 months in the LIBERATE study (primary endpoint) [1]



Table 1: Changes in secondary endpoint measures after 12 months in the LIBERATE study [1]



Valves and coils

Multiple studies showed improvements in FEV₁, residual volume (RV), 6-minute walk distance (6MWD), and SGRQ scores after treatment with valves (see Table 2) or coils (see Table 3) [2-5].

Table 2: Improvement in FEV₁, RV, 6MWD, and SGRQ scores after treatment with valves [2-5]



Table 3: Improvement in FEV₁, 6MWD, and SGRQ scores after coil therapy [6-8]



The RENEW trial is the largest study comparing coils vs standard of care in patients with severe emphysema [8]. “When looking at the patients who responded to the therapy, unfortunately, only 40% had a successful volume reduction”, stated Prof. Herth. “However, the improvement in those patients was very strong.”

Thermic and chemical procedures

More recently, bronchoscopic thermal vapour ablation (BTVA) and polymeric lung volume reduction (PLVR) have been developed. Both therapies are independent of collateral ventilation and are irreversible. In contrast to valve therapy, BTVA can be used on segmental and PLVR on sub-segmental level. BTVA and PLVR are intended to induce a local inflammation with a following fibrosis and shrinkage, and thus a volume reduction in the treated lung areas. Currently, only patients with predominant upper-lobe emphysema are treated. In some RCTs, both interventions resulted in improvement of lung function, exercise capacity, and quality of life (see Table 4). However, the risk profile of PLVR is unfavourable with a high number of adverse respiratory events [9].

Table 4: Improvement in FEV₁, 6MWD and SGRQ scores after BTVA and PLVR [10-12]



Patient selection and team

In order to maximise responder rates, it is essential to have a proper patient selection program. Furthermore, the lung volume reduction procedure and follow-up should be adequate. A multidisciplinary team, consisting of a pulmonologist, thoracic surgeon, and radiologist should meet weekly or every two weeks. In addition, an expert centre is recommended to treat around 1,000 patients per year. In 2017, an expert panel proposed recommendations regarding patient selection and utilisation of these various techniques for the treatment of patients with advanced emphysema [13].