Stefan Blaas

A Novel Extracorporeal CO2 Removal System: Results of a Pilot Study of Hypercapnic Respiratory Failure in Patients With COPD

BACKGROUND Hypercapnic respiratory failure in patients with COPD frequently requires mechanical ventilatory support. Extracorporeal CO2 removal (ECCO2R) techniques have not been systematically evaluated in these patients. METHODS This is a pilot study of a novel ECCO2R device that utilizes a single venous catheter with high CO2 removal rates at low blood flows. Twenty hypercapnic patients with COPD received ECCO2R. Group 1 (n = 7) consisted of patients receiving noninvasive ventilation with a high likelihood of requiring invasive ventilation, group 2 (n = 2) consisted of patients who could not be weaned from noninvasive ventilation, and group 3 (n = 11) consisted of patients on invasive ventilation who had failed attempts to wean. RESULTS The device was well tolerated, with complications and rates similar to those seen with central venous catheterization. Blood flow through the system was 430.5 ± 73.7 mL/min, and ECCO2R was 82.5 ± 15.6 mL/min and did not change significantly with time. Invasive ventilation was avoided in all patients in group 1 and both patients in group 2 were weaned; PaCO2 decreased significantly (P < .003) with application of the device from 78.9 ± 16.8 mm Hg to 65.9 ± 11.5 mm Hg. In group 3, three patients were weaned, while the level of invasive ventilatory support was reduced in three patients. One patient in group 3 died due to a retroperitoneal bleed following catheterization. CONCLUSIONS This single-catheter, low-flow ECCO2R system provided clinically useful levels of CO2 removal in these patients with COPD. The system appears to be a potentially valuable additional modality for the treatment of hypercapnic respiratory failure.

Lung volume reduction coil treatment for patients with severe emphysema: a European multicentre trial

Background The lung volume reduction (LVR) coil is a minimally invasive bronchoscopic nitinol device designed to reduce hyperinflation and improve elastic recoil in severe emphysema. We investigated the feasibility, safety and efficacy of LVR coil treatment in a prospective multicentre cohort trial in patients with severe emphysema. Methods Patients were treated in 11 centres. Safety was evaluated by recording all adverse events, efficacy by the St Georges Respiratory Questionnaire (SGRQ) as primary endpoint, and pulmonary function testing, modified Medical Research Council dyspnoea score (mMRC) and 6-min walk distance (6MWD) up to 12 months after the final treatment. Results Sixty patients (60.9 ± 7.5 years, forced expiratory volume in 1 s (FEV1) 30.2 ± 6.3% pred) were bronchoscopically treated with coils (55 bilateral, 5 unilateral), with a median of 10 (range 5–15) coils per lobe. Within 30 days post-treatment, seven chronic obstructive pulmonary disease exacerbations (6.1%), six pneumonias (5.2%), four pneumothoraces (3.5%) and one haemoptysis (0.9%) occurred as serious adverse events. At 6 and 12 months, respectively, ΔSGRQ was −12.1±12.9 and −11.1±13.3 points, Δ6MWD was +29.7±74.1 m and +51.4±76 m, ΔFEV1 was +0.11±0.20 L and +0.11±0.30 L, and ΔRV (residual volume) was −0.65±0.90 L and −0.71±0.81 L (all p<0.01). Post hoc analyses showed significant responses for SGRQ, 6MWD and RV in patients with both heterogeneous and homogeneous emphysema. Conclusions LVR coil treatment results in significant clinical improvements in patients with severe emphysema, with a good safety profile and sustained results for up to 1 year. Trial registration number: NCT01328899.

Bronchoscopic Coil Treatment for Patients with Severe Emphysema: A Meta-Analysis.

Background: Bronchoscopic coil treatment has been shown to improve pulmonary function, exercise capacity, and quality of life in patients with severe emphysema. Objectives: To perform a meta-analysis of the results of four independent European clinical trials investigating this coil therapy for emphysema. Methods: Data on all patients included in the four European clinical trials were analyzed for efficacy and safety outcomes. Results: A total of 2,536 coils were placed during 259 procedures in 140 patients. A total of 37 chronic obstructive pulmonary disease exacerbations and 27 pneumonias were recorded as serious adverse events up to 1 year after treatment. The pneumothorax rate was 6.4%. Both 6 and 12 months after treatment, significant (all p < 0.001) improvements were observed for: forced expiratory volume in 1 s [+0.08 liters (±0.19) and +0.08 liters (±0.21)], residual volume [RV; -510 ml (±850) and -430 ml (±720)], 6-min walking distance [6MWD; +44.1 m (±69.8) and +38.1 m (±71.9)], and St. Georges Respiratory Questionnaire score [SGRQ; -9.5 points (±14.3) and -7.7 points (±14.2)]. No differences in any outcome measures were observed between heterogeneous and homogeneous emphysema patients. Only a high baseline RV was found to be an independent predictor of successful treatment. Conclusions: Bronchoscopic coil treatment improves pulmonary function, 6MWD, and quality of life in patients with severe emphysema up to 1 year after treatment, independent of the distribution of the disease.

Endobronchial Coils Versus Lung Volume Reduction Surgery or Medical Therapy for Treatment of Advanced Homogenous Emphysema

Rationale: Bronchoscopic lung volume reduction utilizing shape-memory nitinol endobronchial coils (EBC) may be safer and more effective in severely hyperinflated homogeneous emphysema compared to medical therapy or lung volume reduction surgery (LVRS). Methods: The effect of bilateral EBC in patients with homogeneous emphysema on spirometry, lung volumes and survival was compared to patients with homogeneous emphysema randomized in the National Emphysema Treatment Trial (NETT) to LVRS or medical therapy. NETT participants were selected to match EBC participants in age, baseline spirometry, and gender. Outcomes were compared from baseline, at 6 and 12 months. Results: There were no significant baseline differences in gender in the EBC, NETT-LVRS or medical treatment patients. At baseline no differences existed between EBC and NETT-LVRS patients in forced expiratory volume in 1 second ( FEV1) or total lung capacity (TLC) %-predicted; residual volume (RV) and diffusing capacity of the lung for carbon monoxide (DLco) %-predicted were higher in the EBC group compared to NETT-LVRS (p < 0.001). Compared to the medical treatment group, EBC produced greater improvements in FEV1 and RV but not TLC at 6 months. FEV1 and RV in the EBC group remained significantly improved at 12-months compared to the medical treatment group. While all 3 therapies improved quality of life, survival at 12 months with EBC or medical therapy was greater than NETT-LVRS. Conclusion: EBC may be a potential therapeutic option in patients with severe homogeneous emphysema and hyperinflation who are already receiving optimal medical treatment.