***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Although lung volume reduction surgery improves survival in selected patients with emphysema , there has been ongoing interest in developing and evaluating bronchoscopic approaches to try to reduce lung volumes with less morbidity and mortality . The placement of endobronchial valves is one such technique , and although some patients have had a significant improvement , responses have been inconsistent because collateral ventilation prevents lobar atelectasis . We describe the protocol of a trial ( IS RCT N04761234 ) aim ed to show that a responder phenotype , patients with heterogeneous emphysema and intact interlobar fissures on CT scanning , can be identified prospect ively , leading to a consistent benefit in clinical practice This multicentre , blinded , sham-controlled study was performed to assess the safety and effectiveness of bronchial valve therapy using a bilateral upper lobe treatment approach without the goal of lobar atelectasis . Patients with upper lobe predominant severe emphysema were r and omised to bronchoscopy with ( n=37 ) or without ( n=36 ) IBV Valves  for a 3-month blinded phase . A positive responder was defined as having both a ≥4-point improvement in St George ’s Respiratory Question naire ( SGRQ ) and a lobar volume shift as measured by quantitative computed tomography . At 3 months , there were eight ( 24 % ) positive responders in the treated group versus none ( 0 % ) in the control group ( p=0.002 ) . Also , there was a significant shift in volume in the treated group from the upper lobes ( mean±sd -7.3±9.0 % ) to the non-treated lobes ( 6.7±14.5 % ) , with minimal change in the control group ( p<0.05 ) . Mean SGRQ total score improved in both groups ( treatment : -4.3±16.2 ; control : -3.6±10.7 ) . The procedure and devices were well tolerated and there were no differences in adverse events reported in the treatment and control groups . Treatment with bronchial valves without complete lobar occlusion in both upper lobes was safe , but not effective in the majority of patients Background There is a clinical need for therapeutic options to reduce hyperinflation associated with severe emphysema . Endobronchial Coils ( coils ) are nitinol devices implanted bronchoscopically under fluoroscopic guidance to re-tension the lung . We report the medium term effectiveness and safety of coils in a study of patients with emphysema . Methods Forty five subjects with severe airflow obstruction and hyperinflation received bilateral sequential treatment with coils ( 30 day interval between treatments ) as part of a r and omised controlled trial with a primary endpoint 90 days after the final treatment ( Clinical trials.gov NCT01334307 ) . Further assessment s were made at 180 and 360 days and in this study the primary outcome was the effect of coil treatment on the St. George ’s Respiratory Question naire ( SGRQ ) 360 days following treatment . Results At 360 days following treatment , there was an improvement in the SGRQ score of -6.1±14.0 points ( p = 0.01 ) compared to baseline . Improvements in secondary outcomes were seen with increases in forced expiratory volume in the first second of 8.9 ±22.2 % ( p = 0.002 ) and 6-minute walking distance of 34.1±52.4 m ( p = 0.003 ) . The safety profile was acceptable out to 360 days post-treatment . Conclusions Statistically and clinical ly meaningful benefits in quality of life , exercise capacity and pulmonary function in patients treated with coils are sustained twelve months after treatment . Trial registration information Clinical trials.gov NCT01334307 BACKGROUND In today 's cost-conscious health care environment , obtaining timely and accurate economic information regarding new medical technologies has become extremely important . The National Emphysema Treatment Trial , a multicenter , r and omized controlled trial of lung volume reduction surgery ( LVRS ) plus medical therapy , versus medical therapy for patients with severe emphysema , includes a parallel cost-effectiveness analysis . METHODS The analysis is design ed to determine the cost-effectiveness of LVRS versus medical therapy for those who are eligible for the procedure . After describing theoretical foundations of cost-effectiveness analysis as they apply to this study , we describe the economic and quality of life data that are being collected alongside the clinical trial , methods of analysis , and approach to presenting the results . RESULTS The cost-effectiveness of LVRS relative to medical therapy will be presented as costs per quality -adjusted life years gained . CONCLUSIONS This analysis will provide timely economic data that can be considered alongside the clinical results of the National Emphysema Treatment Trial . As one of the largest clinical trials to include a parallel , prospect i ve cost-effectiveness analyses , this study will also provide valuable practical information about conducting an economic analysis alongside a multicenter clinical trial Background Both tissue sealants and buttressing have been advocated to reduce alveolar air leaks from staple lines following Lung Volume Reduction Surgery ( LVRS ) . However , the long term detrimental effects of buttressing material are increasingly apparent . We performed a pilot prospect i ve r and omised self controlled trial in patients undergoing LVRS comparing BioGlue and Peri-strips as adjuncts in preventing alveolar air-leaks . Methods A pilot prospect i ve self controlled clinical trial was conducted in patients undergoing LVRS . Each patient was treated with BioGlue on one side and pericardial buttress on the other side as an adjunct to the staple line . The sides were r and omised for adjuncts with each patient acting as his own control . Duration of air leak , intercostal drainage and time to chest drain removal were the study end points . Results 10 patients undergoing the procedure were recruited between December 2005 and October 2007 . There were 6 men and the mean age was 59.8 ± 4.9 years . There was one mortality due to multi-organ failure . The BioGlue treated side had a shorter mean duration of air-leak ( 3.0 ± 4.6 versus 6.5 ± 6.9 days ) , lesser chest drainage volume ( 733 ± 404 ml versus 1001 ± 861 ) and shorter time to chest drain removal ( 9.7 ± 10.6 versus 11.5 ± 11.1 days ) compared with Peri-strips . Conclusion This study demonstrates comparable efficacy of BioGlue and Peri-strips , however there is a trend favouring the BioGlue treated side in terms of reduction in air-leak , chest drainage volumes , duration of chest drainage and significant absence of complications . A larger sample size is needed to vali date this result OBJECTIVE The National Emphysema Treatment Trial ( NETT ) is a r and omized , multicenter , clinical trial comparing two different methods of lung volume reduction surgery plus medical therapy to medical treatment alone in patients with advanced emphysema . The purpose of this article was to use the data obtained from the NETT to assess the ability of the single-breath diffusing capacity of the lung for carbon monoxide ( DLCO ) to predict the need for supplemental oxygen during rest and exercise , as well as overall exercise capacity . METHODS One thous and seventy-one patients with a mean ( + /- SD ) FEV(1 ) of 0.76 + /- 0.24 L were studied . RESULTS The mean DLCO was 8.0 + /- 3.1 mL/min/mm Hg ( 28 + /- 10 % of predicted ) . The mean resting PaO(2 ) was 64 + /- 10 mm Hg . There was a positive association between DLCO and both resting PaO(2 ) and the requirement for oxygen during a walk at 1 mile per hour ( mph ) . The odds of requiring supplemental oxygen while walking at 1 mph was nine times greater in patients with a DLCO of < or = 20 % of predicted than for patients with a DLCO of > 35 % of predicted , after adjusting for age and gender . Eighty four percent of individuals with a DLCO of < or = 20 % required supplemental oxygen with low levels of exercise compared to 38 % of those with a DLCO of > 35 % . CONCLUSION Our results demonstrated that patients with reduced DLCO , particularly when < or = 20 % of predicted , are more likely to have reduced PaO(2 ) at rest and are more likely to require supplemental oxygen with low levels of activity . Thus , DLCO is useful in evaluating whether supplemental oxygen is required for exercise The National Emphysema Treatment Trial ( NETT ) was a multicenter r and omized controlled trial comparing medical treatment plus lung-volume-reduction surgery ( LVRS ) to medical treatment alone for the treatment of severe emphysema . The primary outcomes specified for the trial were mortality from all causes and change in functional status as indicated by the change in maximum exercise capacity measured two years after r and omization . A secondary objective of the trial was to define criteria to identify subgroups of patients at risk of harm or benefit from LVRS . Stopping guidelines for safety and efficacy based on 30-day mortality and a combination of overall mortality and functional status at two years were specified at the inception of the trial . Although specific subgroups of patients likely to benefit were not identified in advance , several clinical factors were specified as likely to be important in defining subgroups with differential outcome . In May 2001 , with 40 % of expected deaths accrued , the Data and Safety Monitoring Board determined that a subgroup of patients was at significantly higher risk of 30-day mortality from LVRS without counterbalancing evidence of functional benefit , and recommended that the protocol be modified to exclude further r and omization of such patients . The trial 's sponsor , the National Heart , Lung and Blood Institute , accepted the recommendation , which was rapidly communicated to participating clinics . This paper describes the operational aspects of identification of the subgroup and implementation of the recommendation to continue the trial , but to terminate enrollment of new patients in the subgroup . These aspects include notification of the investigators , the institutional review boards , the Research Group , the patients and the medical community . We also describe the repercussions of the publication and the misinterpretations of the results based on media coverage BACKGROUND Pulmonary function may improve after surgical resection of the most severely affected lung tissue ( lung-reduction surgery ) in patients with diffuse emphysema . The basic mechanisms responsible for the improvement , however , are not known . METHODS We studied 20 patients with diffuse emphysema before and at least three months after either a unilateral or a bilateral lung-reduction procedure .  Clinical benefit was assessed by measurement of the six-minute walking distance and the transitional-dyspnea index , which is a subjective rating of the change from base line in functional impairment and the threshold for effort- and task- dependent dyspnea . Pressure-volume relations in the lungs were measured with static expiratory esophageal-balloon techniques , and right ventricular systolic function was assessed by echocardiography . RESULTS The patients had significant improvement in the transitional-dyspnea index after surgery ( P<0.001 ) . The mean ( + /-SD ) coefficient of retraction , an indicator of elastic recoil of the lung , improved ( from 1.3+/-0.6 cm of water per liter before surgery to 1.8+/-0.8 after , P<0.001 ) . Sixteen patients with increased elastic recoil had a greater increase in the distance walked in six minutes than the other four patients , in whom recoil did not increase ( P=0.02 ) . The improved lung recoil led to disproportionate decreases in residual volume as compared with total lung capacity ( 16 percent vs. 6 percent ) , but the decreases in both values were significant ( P<0.001 ) . Forced expiratory volume in one second increased ( from 0.87+/-0.36 to 1.11+/-0.45 liters , P<0.001 ) . End-expiratory esophageal pressure also decreased ( P=0.002 ) . These improvements in lung mechanics led to a decrease in arterial partial pressure of carbon dioxide form 42+/-6 to 38+/-5 mm Hg ( P=0.006 ) . Furthermore , the fractional change in right ventricular area , an indicator of systolic function , increased from 0.33+/-0.11 to 0.38+/-0.010 ( P=0.02 ) . CONCLUSIONS Lung-reduction surgery can produce increases in the elastic recoil of the lung in patients with diffuse emphysema , leading to short-term improvement in dyspnea and exercise tolerance Background : In patients with heterogeneous emphysema , surgical and bronchoscopic lung volume reduction ( LVR ) treatments are available . However , for patients with homogeneous emphysema these treatments are hardly investigated and seem less effective . Bronchoscopic LVR coil treatment has been shown to be effective in patients with heterogeneous emphysema , but this treatment has not been exclusively investigated in homogeneous emphysema . Objectives : The aim of this study was to investigate the safety and efficacy of LVR coil treatment in patients with homogeneous emphysema . Methods : In this single-arm , open-label study , patients received a maximum of 12 LVR coils ( PneumRx Inc. , Mountain View , Calif. , USA ) in each upper lobe in two sequential procedures . Tests were performed at baseline and at 6 months . The primary endpoint was the improvement from baseline in 6-min walking distance ( 6MWD ) after treatment . Results : Ten patients with severe airway obstruction and hyperinflation were treated . A median of 11 ( range 10 - 12 ) coils were placed in each lung . Two chronic obstructive pulmonary disease exacerbations and one small pneumothorax were recorded as serious adverse events . At 6 months , 6MWD had improved from 289 to  
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Trials in this review furthermore provided evidence of low to moderate quality showing that improvements in lung function parameters other than forced expiratory volume in one second ( FEV1 ) , quality of life and exercise capacity were more likely with LVRS than with usual follow-up .
Adverse events were more common with LVRS than with control , specifically the occurrence of ( persistent ) air leaks , pulmonary morbidity ( e.g. pneumonia ) and cardiovascular morbidity .
Although LVRS leads to an increase in quality -adjusted life-years ( QALYs ) , the procedure is relatively costly overall .
Lung volume reduction surgery , an effective treatment for selected patients with severe emphysema , may lead to better health status and lung function outcomes , specifically for patients who have upper lobe-predominant emphysema with low exercise capacity , but the procedure is associated with risks of early mortality and adverse events