Figures
- FIGURE 1
Endobronchial valve (EBV) treatment for emphysema, summary of treatment selection and outcome. The key selection criteria for success (do) and restraints for treatment (don't) are shown. The criteria for success (do) are: severe emphysema; complete interlobar fissure (no collateral flow); severe hyperinflation (residual volume (RV) >175% pred, RV/total lung capacity (TLC) >55%); symptomatic; non-smoking; on optimal treatment; and stable condition. The criteria for restraints (don't) are: presence of a suspect nodule; pleural pathology; severe bronchiectasis; incomplete fissure; fibrosis; severe cardiac comorbidity (i.e. pulmonary arterial hypertension (PAH), congestive heart failure (CHF) and coronary artery disease (CAD)); infectious lung disease; chronic bronchitis or asthma; prior lobectomy or lung volume reduction surgery (LVRS) on treatment side; hypercapnia/hypoxaemia; and immunocompromised. The figure also shows the mean responder rates and percentage of risk related to EBV treatment from the four published randomised controlled trials. Responder rates are the percentage of patients who reached the earlier established minimal important difference: forced expiratory volume in 1s (FEV1) ≥12% (STELVIO ≥10%), RV ≥430 mL (LIBERATE ≥310 mL), 6-min walk distance (6MWD) ≥25 m, St George's Respiratory Questionnaire (SGRQ) ≥4 points. #: modified Medical Research Council scale ≥2 or 100 m<6MWD<500 m; ¶: partial pressure of carbon dioxide >60 mmHg/partial pressure of oxygen <45 mmHg.
Tables
- TABLE 1
Overview of results of the four randomised controlled trials performed to date using the Chartis measurement
STELVIO [3] IMPACT [4] TRANSFORM [1] LIBERATE [2] Patients n EBV: 34; SoC: 34 EBV: 43; SoC: 50 EBV: 65; SoC: 32 EBV: 128; SoC: 62 Emphysema distribution Heterogeneous and homogeneous Homogeneous Heterogeneous Heterogeneous Procedure Procedure time min 18 (6–51) NR NR 29 (4–123) Valves used n 4 (2–7) 4 4 (2–8) 4 (2–8) Hospital stay days 1 (1–13) 6 (3–40) 4 (1–49) NR Efficacy Target lobe volume reduction# mL −1366 −1195 −1090 −1142 Between group difference 6 months follow-up 3 months follow-up 6 months follow-up 12 months follow-up Change in lung function FEV1 +17.8%§ +17%§ +29%§ +18%§ RV mL −831 −480§ −700§ −522§ Change in exercise capacity 6MWD m +74§ +40§ +79§ +39§ Change in patient-centred outcomes SGRQ total score −14.7 −9.7§ −6.5§ −7.1§ mMRC change −0.61 −0.57§ −0.6§ −0.8§ Physical activity steps per day +1340 (+57%) NR NR NR Responder rates¶ FEV1 72% 40% 66% 56% RV 71% 44% 68% 62% 6MWD 79% 57% 66% 42% SGRQ 87% 50% 65% 56% Safety+ Pneumothorax 18% 26% 29% 34% Valve retainment 79% 93% 97% 94% Re-bronchoscopy 35% 19% 28% 27% Deaths 3% 0% 2% 4% Data are presented as median (range) or mean change, unless otherwise stated. FEV1: forced expiratory volume in 1 s; RV: residual volume; 6MWD: 6-min walk distance; SGRQ: St George's Respiratory Questionnaire; mMRC: modified Medical Research Council scale; EBV: endobronchial valve; SoC: standard of care; NR: not reported. #: change in the EBV group only; ¶: percentage of patients who reached the earlier established minimal important difference: FEV1 ≥12% (STELVIO ≥10%), RV ≥430 mL (LIBERATE ≥310 mL), 6MWD ≥25 m, SGRQ ≥4 points; +: EBV group only; §: intention to treat analyses.
- TABLE 2
Challenges and future directions of endobronchial valve (EBV) treatment
Advanced patient selection Clinical patient characteristics To define the cut-offs regarding clinical patient characteristics such as degree of obstruction, static hyperinflation, diffusion capacity, blood oxygen tension, exercise capacity, pulmonary hypertension, comorbidities, etc. for procedure-related risk estimation and efficacy outcome. Emphysema severity To define the exact role of quantitative lobar tissue destruction scores related to outcomes. Prediction of collateral ventilation To define the optimal cut-off (both lower and upper limit) for the degree of fissure integrity calculated on CT. To establish the optimal method of measurement and interpretation of the Chartis system signal in the measurement of collateral ventilation. Prediction of response using quantification To further develop quantitative HRCT software analysis with accurate assessment of fissure integrity, emphysema scores, the amount of air trapping and lung perfusion, all on a lobar level. Multidisciplinary team To establish a solid base for an emphysema multidisciplinary team like our lung cancer and ILD multidisciplinary team meetings. Therapeutic challenges The positioning of LVRS versus EBV treatment Not all patients that are good candidates for surgery are good candidates for valves and vice versa. To create decision making guidance for candidate patients for both techniques. To create a step-up treatment guidance for initial good responders to EBV treatment. Closing the interlobar collateral channels To develop treatments that successfully close the collateral channels which would significantly increase the patient population that could potentially benefit from EBV treatment. Treatment decisions in patients with homogeneous disease To identify the best treatment option for patients with real homogeneous disease. EBV treatment or coil treatment? Granulation tissue To identify predictors or risk factors for the development of granulation tissue after EBV treatment (and in fact after every implantable device in the human airways). Burning questions Long-term effects To establish the long-term efficacy, cost-efficiency, effect on exacerbations, hospitalisations, survival and adverse events. The interaction with pulmonary rehabilitation. The combination of EBV treatment and pulmonary rehabilitation could strengthen the effect of the EBV treatment. The best timing of the rehabilitation programme has not been investigated to date. A look in the crystal globe Potential future developments To develop new or customised valves. To develop an advanced Chartis device that could be helpful in target lobe selection. To establish the role of advanced functional imaging with patient selection To combine different endoscopic and/or surgical techniques. LVRS: lung volume reduction surgery; CT: computed tomography; HRCT: high-resolution CT; ILD: interstitial lung disease.
