Dirk-Jan Slebos

Radiological and clinical outcomes of using Chartis (TM) to plan endobronchial valve treatment

One-way endobronchial valves (EBVs) have been shown to relieve symptoms of emphysema, particularly in patients without collateral ventilation (CV) between the target and adjacent lobes. In this study, we investigated the ability of the bronchoscopic Chartis™ Pulmonary Assessment System to predict treatment response by determining the presence of CV. 80 EBV patients underwent a pre-treatment Chartis assessment. Before and 30 days after implantation, high-resolution computed tomography scans were taken to determine target lobe volume reduction (TLVR). A pre- to post-treatment reduction of ≥350 mL was defined as significant. In addition, clinical outcomes (forced expiratory volume in 1 s (FEV1), 6-min walk test and St George’s Respiratory Questionnaire) were compared over the same time period. Of the 51 patients classified as having an absence of CV according to their Chartis reading, 36 showed a TLVR ≥350 mL. 29 patients were classified as having CV, and of these 24 did not meet this TLVR cut-off. Chartis showed an accuracy level of 75% in predicting whether or not the TLVR cut-off would be reached. Those predicted to respond showed significantly greater TLVR (p<0.0001) and FEV1 improvement (p=0.0013) than those predicted not to respond. Chartis is a safe and effective method of predicting response to EBV treatment.

Endobronchial Valves for Emphysema without Interlobar Collateral Ventilation

BACKGROUND Bronchoscopic lung-volume reduction with the use of one-way endobronchial valves is a potential treatment for patients with severe emphysema. To date, the benefits have been modest but have been hypothesized to be much larger in patients without interlobar collateral ventilation than in those with collateral ventilation. METHODS We randomly assigned patients with severe emphysema and a confirmed absence of collateral ventilation to bronchoscopic endobronchial-valve treatment (EBV group) or to continued standard medical care (control group). Primary outcomes were changes from baseline to 6 months in forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and 6-minute walk distance. RESULTS Eighty-four patients were recruited, of whom 16 were excluded because they had collateral ventilation (13 patients) or because lobar segments were inaccessible to the endobronchial valves (3 patients). The remaining 68 patients (mean [±SD] age, 59±9 years; 46 were women) were randomly assigned to the EBV group (34 patients) or the control group (34). At baseline, the FEV1 and FVC were 29±7% and 77±18% of the predicted values, respectively, and the 6-minute walk distance was 374±86 m. Intention-to-treat analyses showed significantly greater improvements in the EBV group than in the control group from baseline to 6 months: the increase in FEV1 was greater in the EBV group than in the control group by 140 ml (95% confidence interval [CI], 55 to 225), the increase in FVC was greater by 347 ml (95% CI, 107 to 588), and the increase in the 6-minute walk distance was greater by 74 m (95% CI, 47 to 100) (P<0.01 for all comparisons). By 6 months, 23 serious adverse events had been reported in the EBV group, as compared with 5 in the control group (P<0.001). One patient in the EBV group died. Serious treatment-related adverse events in this group included pneumothorax (18% of patients) and events requiring valve replacement (12%) or removal (15%). CONCLUSIONS Endobronchial-valve treatment significantly improved pulmonary function and exercise capacity in patients with severe emphysema characterized by an absence of interlobar collateral ventilation. (Funded by the Netherlands Organization for Health Research and Development and the University Medical Center Groningen; Netherlands Trial Register number, NTR2876.).

Bronchoscopic Lung Volume Reduction Coil Treatment of Patients With Severe Heterogeneous Emphysema

BACKGROUND The lung volume reduction coil (LVR-coil), a new experimental device to achieve lung volume reduction by bronchoscopy in patients with severe emphysema, works in a manner unaffected by collateral airflow. We investigated the safety and efficacy of LVR-coil treatment in patients with heterogeneous emphysema. METHODS In this prospective cohort pilot study, patients were treated bronchoscopically with Nitinol LVR-coils under fluoroscopic guidance in either one procedure or two sequential procedures. Follow-up tests included the St. George Respiratory Questionnaire (SGRQ), pulmonary function testing, and the 6-min walk test (6MWT). RESULTS Twenty-eight LVR-coil procedures were performed in 16 patients (baseline FEV₁, 28% [± 7.6%] predicted). Four patients were treated in one lung, and 12 patients were treated in both lungs. A median of 10 (5-12) coils was placed per lung in 36.5 (20-60) min. Adverse events (AEs) rated as possibly related to either the device or the procedure < 30 days after treatment were pneumothorax (n ± 1), pneumonia (n ± 2), COPD exacerbation (n ± 6), chest pain (n ± 4), and mild (< 5 mL) hemoptysis (n ± 21). From 30 days to 6 months, the AEs that occurred were pneumonia (n ± 3) and COPD exacerbation (n ± 14). All events resolved with standard care. Six months after LVR-coil treatment, there were significant improvements in SGRQ (-14.9 points [± 12.1 points, with 11 patients improving by > 4 points]), FEV₁ (+14.9% ± 17.0%), FVC (+13.4% ± 12.9%), residual volume (-11.4% ± 9.0%), and 6MWT (+84.4 ± 73.4 m), all P < .005. CONCLUSIONS LVR-coil treatment is a promising technique for the treatment of patients with severe heterogeneous emphysema. The treatment is technically feasible and results in significant improvements in pulmonary function, exercise capacity, and quality of life, with an acceptable safety profile. TRIAL REGISTRY ClinicalTrials.gov; No.:NCT01220908; URL: www.clinicaltrials.gov

Heme oxygenase-1 and carbon monoxide in pulmonary medicine

Heme oxygenase-1 (HO-1), an inducible stress protein, confers cytoprotection against oxidative stress in vitro and in vivo. In addition to its physiological role in heme degradation, HO-1 may influence a number of cellular processes, including growth, inflammation, and apoptosis. By virtue of anti-inflammatory effects, HO-1 limits tissue damage in response to proinflammatory stimuli and prevents allograft rejection after transplantation. The transcriptional upregulation of HO-1 responds to many agents, such as hypoxia, bacterial lipopolysaccharide, and reactive oxygen/nitrogen species. HO-1 and its constitutively expressed isozyme, heme oxygenase-2, catalyze the rate-limiting step in the conversion of heme to its metabolites, bilirubin IXα, ferrous iron, and carbon monoxide (CO). The mechanisms by which HO-1 provides protection most likely involve its enzymatic reaction products. Remarkably, administration of CO at low concentrations can substitute for HO-1 with respect to anti-inflammatory and anti-apoptotic effects, suggesting a role for CO as a key mediator of HO-1 function. Chronic, low-level, exogenous exposure to CO from cigarette smoking contributes to the importance of CO in pulmonary medicine. The implications of the HO-1/CO system in pulmonary diseases will be discussed in this review, with an emphasis on inflammatory states.

Bronchial thermoplasty: Long-term safety and effectiveness in patients with severe persistent asthma

BACKGROUND Bronchial thermoplasty (BT) has previously been shown to improve asthma control out to 2 years in patients with severe persistent asthma. OBJECTIVE We sought to assess the effectiveness and safety of BT in asthmatic patients 5 years after therapy. METHODS BT-treated subjects from the Asthma Intervention Research 2 trial (ClinicalTrials.govNCT01350414) were evaluated annually for 5 years to assess the long-term safety of BT and the durability of its treatment effect. Outcomes assessed after BT included severe exacerbations, adverse events, health care use, spirometric data, and high-resolution computed tomographic scans. RESULTS One hundred sixty-two (85.3%) of 190 BT-treated subjects from the Asthma Intervention Research 2 trial completed 5 years of follow-up. The proportion of subjects experiencing severe exacerbations and emergency department (ED) visits and the rates of events in each of years 1 to 5 remained low and were less than those observed in the 12 months before BT treatment (average 5-year reduction in proportions: 44% for exacerbations and 78% for ED visits). Respiratory adverse events and respiratory-related hospitalizations remained unchanged in years 2 through 5 compared with the first year after BT. Prebronchodilator FEV₁ values remained stable between years 1 and 5 after BT, despite a 18% reduction in average daily inhaled corticosteroid dose. High-resolution computed tomographic scans from baseline to 5 years after BT showed no structural abnormalities that could be attributed to BT. CONCLUSIONS These data demonstrate the 5-year durability of the benefits of BT with regard to both asthma control (based on maintained reduction in severe exacerbations and ED visits for respiratory symptoms) and safety. BT has become an important addition to our treatment armamentarium and should be considered for patients with severe persistent asthma who remain symptomatic despite taking inhaled corticosteroids and long-acting β₂-agonists.

Bronchoscopic lung volume reduction with a dedicated coil: a clinical pilot study

Background: Lung volume reduction aims to improve symptoms by reducing hyperinflation. Endoscopic approaches so far have generally been hampered in their efficacy by collateral ventilation (CV). We sought to determine the safety and feasibility of a new endoscopic lung volume reduction approach independent of the effects of CV. Methods: Patients with severe emphysema were eligible. Inclusion and exclusion criteria were modeled after the National Emphysema Treatment Trial (NETT) study. Homogenous and heterogeneous disease was allowed. Treatment consisted of the placement of coils into the parenchyma of the most diseased area with the intent of achieving parenchymal compression. Primary endpoints were safety and feasibility assessments. Secondary endpoints were efficacy outcomes. Results: Eleven patients underwent 21 procedures. Procedures were performed under general anesthesia and lasted 45±15 minutes and per procedure 4.9±0.6 coils were placed. All procedures were well tolerated. The total follow-up time was 7-11 months and in that time 33 adverse events were reported, none of them severe. No pneumothorax occurred. Efficacy seemed better in heterogeneous rather than homogenous disease. Conclusion: Endoscopic lung volume reduction with coils is safe and feasible. Further studies of the efficacy are indicated.

Mitochondrial dysfunction in copd patients with low body mass index

Respir J 2007; 29: 757–760. 2 Tschopp JM, Brutsche M, Frey JG. Treatment of complicated spontaneous pneumothorax by simple talc pleurodesis under thoracoscopy and local anaesthesia. Thorax 1997; 52: 329–332. 3 Vanderschueren RG. [Pleural talcage in patients with spontaneous pneumothorax (author’s transl.).] Poumon Coeur 1981; 37: 273–276. 4 Lange P, Mortensen J, Groth S. Lung function 22–35 years after treatment of idiopathic spontaneous pneumothorax with talc poudrage or simple drainage. Thorax 1988; 43: 559–561. 5 Schoenenberger RA, Haefeli WE, Weiss P, Ritz R. Evaluation of conventional chest tube therapy for iatrogenic pneumothorax. Chest 1993; 104: 1770–1772. 6 Abolnik IZ, Lossos IS, Gillis D, Breuer R. Primary spontaneous pneumothorax in men. Am J Med Sci 1993; 305: 297–303. 7 Ben-Nun A, Soudack M, Best LA. Video-assisted thoracoscopic surgery for recurrent spontaneous pneumothorax: the long-term benefit. World J Surg 2006; 30: 285–290. 8 Noppen M. Management of primary spontaneous pneumothorax. Curr Opin Pulm Med 2003; 9: 272–275.

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.

Lipid-soluble components in cigarette smoke induce mitochondrial production of reactive oxygen species in lung epithelial cells

Reactive oxygen species (ROS) present in cigarette smoke (CS) are thought to contribute to the development of COPD. Although CS-ROS can hardly enter airway epithelial cells, and certainly not the circulation, systemic levels of ROS have been found to be elevated in COPD patients. We hypothesize that lipophilic components present in CS can enter airway epithelial cells and increase intracellular ROS production by disturbing mitochondrial function. Different airway epithelial cells were exposed to CS extract (CSE), hexane-treated CSE (CSE without lipophilic components), gaseous-phase CS, and water-filtered CS (gaseous-phase CS without ROS). Mitochondrial membrane potential (Deltapsi(m)) and ATP levels were assessed using the bronchial epithelial cell line Beas-2b. ROS generation measured directly by DCF fluorescence and indirectly by measuring free thiol groups (-SH) upon exposure to CS was assessed using lung alveolar epithelial cells devoid of functional mitochondria (A549-rho0), with normal A549 cells serving as controls. In Beas-2b cells, CSE (4 h) caused a dose-dependent decrease in Deltapsi(m) and ATP levels, whereas hexane-treated CSE did not. DCF fluorescence in A549 cells increased in response to CSE, whereas this was not the case in A549-rho0 cells. Exposure of A549 cells to CS resulted in a rapid decrease in free -SH, whereas exposure to ROS-depleted CS only resulted in a delayed decrease. This delayed decrease was less pronounced in A549-rho0 cells. Lipophilic components in CS disturb mitochondrial function, which contributes to increased intracellular generation of ROS. Our results are of importance in understanding the systemic effects of smoking observed in patients with COPD.

Characterisation of cell adhesion in airway epithelial cell types using electric cell–substrate impedance sensing

Research on epithelial cell lines and primary epithelium is required to dissect the mechanisms underlying the structural abnormalities in airway epithelium observed for respiratory diseases, including asthma and chronic obstructive pulmonary disease. The novel electric cell–substrate impedance sensing technique was used to monitor cell adhesion/spreading, barrier function and wound healing. Primary bronchial epithelium was compared with airway epithelial cell lines 16HBE14o-, BEAS-2B, NCI-H292 and A549. BEAS-2B, A549 and primary cells form a confluent monolayer more rapidly than do 16HBE14o- cells. In contrast, 16HBE14o- cells form stronger intercellular contacts, with a 10-fold higher resistance than BEAS-2B, A549 and NCI-H292 cells and a five-fold increase over primary cells. Accordingly, expression of the adhesion molecules zona occludens-1 and E-cadherin was highest in 16HBE14o- cells. These molecules were localised in intercellular junctions in both 16HBE14o- and primary cells. Finally, restoration of barrier function upon injury was impaired in BEAS-2B compared to 16HBE14o- cells. In conclusion, epithelial cell types display remarkable phenotypic differences and should, accordingly, be used to address specific research questions. 16HBE14o- cells appear most suitable for studies on barrier formation, whereas resemblance in attachment of primary and BEAS-2B and A549 cells makes the latter more important for translational research on cell–matrix contact.