In the recent years, a variety of bronchoscopic lung volume reduction (BLVR) procedures
have emerged that may provide a treatment option to participants suffering from moderate
to severe chronic obstructive pulmonary disease (COPD). To assess the effects of BLVR
on the short‐ and long‐term health outcomes in participants with moderate to severe
COPD and determine the effectiveness and cost‐effectiveness of each individual technique.
Studies were identified from the Cochrane Airways Group Specialised Register (CAGR)
and by handsearching of respiratory journals and meeting abstracts. All searches are
current until 07 December 2016. We included randomized controlled trials (RCTs). We
included studies reported as full text, those published as abstract only and unpublished
data, if available. Two independent review authors assessed studies for inclusion
and extracted data. Where possible, data from more than one study were combined in
a meta‐analysis using RevMan 5 software. AeriSeal One RCT of 95 participants found
that AeriSeal compared to control led to a significant median improvement in forced
expiratory volume in one second (FEV 1 ) (18.9%, interquartile range (IQR) ‐0.7% to
41.9% versus 1.3%, IQR ‐8.2% to 12.9%), and higher quality of life, as measured by
the St Georges Respiratory Questionnaire (SGRQ) (‐12 units, IQR ‐22 units to ‐5 units,
versus ‐3 units, IQR ‐5 units to 1 units), P = 0.043 and P = 0.0072 respectively.
Although there was no significant difference in mortality (Odds Ratio (OR) 2.90, 95%
CI 0.14 to 62.15), adverse events were more common for participants treated with AeriSeal
(OR 3.71, 95% CI 1.34 to 10.24). The quality of evidence found in this prematurely
terminated study was rated low to moderate. Airway bypass stents Treatment with airway
bypass stents compared to control did not lead to significant between‐group changes
in FEV 1 (0.95%, 95% CI ‐0.16% to 2.06%) or SGRQ scores (‐2.00 units, 95% CI ‐5.58
units to 1.58 units), as found by one study comprising 315 participants. There was
no significant difference in mortality (OR 0.76, 95% CI 0.21 to 2.77), nor were there
significant differences in adverse events (OR 1.33, 95% CI 0.65 to 2.73) between the
two groups. The quality of evidence was rated moderate to high. Endobronchial coils
Three studies comprising 461 participants showed that treatment with endobronchial
coils compared to control led to a significant between‐group mean difference in FEV
1 (10.88%, 95% CI 5.20% to 16.55%) and SGRQ (‐9.14 units, 95% CI ‐11.59 units to
‐6.70 units). There were no significant differences in mortality (OR 1.49, 95% CI
0.67 to 3.29), but adverse events were significantly more common for participants
treated with coils (OR 2.14, 95% CI 1.41 to 3.23). The quality of evidence ranged
from low to high. Endobronchial valves Five studies comprising 703 participants found
that endobronchial valves versus control led to significant improvements in FEV 1
(standardized mean difference (SMD) 0.48, 95% CI 0.32 to 0.64) and scores on the SGRQ
(‐7.29 units, 95% CI ‐11.12 units to ‐3.45 units). There were no significant differences
in mortality between the two groups (OR 1.07, 95% CI 0.47 to 2.43) but adverse events
were more common in the endobronchial valve group (OR 5.85, 95% CI 2.16 to 15.84).
Participant selection plays an important role as absence of collateral ventilation
was associated with superior clinically significant improvements in health outcomes.
The quality of evidence ranged from low to high. Intrabronchial valves In the comparison
of partial bilateral placement of intrabronchial valves to control, one trial favoured
control in FEV 1 (‐2.11% versus 0.04%, P = 0.001) and one trial found no difference
between the groups (0.9 L versus 0.87 L, P = 0.065). There were no significant differences
in SGRQ scores (MD 2.64 units, 95% CI ‐0.28 units to 5.56 units) or mortality rates
(OR 4.95, 95% CI 0.85 to 28.94), but adverse events were more frequent (OR 3.41, 95%
CI 1.48 to 7.84) in participants treated with intrabronchial valves. The lack of functional
benefits may be explained by the procedural strategy used, as another study (22 participants)
compared unilateral versus partial bilateral placement, finding significant improvements
in FEV 1 and SGRQ when using the unilateral approach. The quality of evidence ranged
between moderate to high. Vapour ablation One study of 69 participants found significant
mean between‐group differences in FEV 1 (14.70%, 95% CI 7.98% to 21.42%) and SGRQ
(‐9.70 units, 95% CI ‐15.62 units to ‐3.78 units), favouring vapour ablation over
control. There was no significant between‐group difference in mortality (OR 2.82,
95% CI 0.13 to 61.06), but vapour ablation led to significantly more adverse events
(OR 3.86, 95% CI 1.00 to 14.97). The quality of evidence ranged from low to moderate.
Results for selected BLVR procedures indicate they can provide significant and clinically
meaningful short‐term (up to one year) improvements in health outcomes, but this was
at the expense of increased adverse events. The currently available evidence is not
sufficient to assess the effect of BLVR procedures on mortality. These findings are
limited by the lack of long‐term follow‐up data, limited availability of cost‐effectiveness
data, significant heterogeneity in results, presence of skew and high CIs, and the
open‐label character of a number of the studies. Review question Do bronchoscopic
lung volume reduction (BLVR) procedures improve health outcomes, without leading to
an increased chance of death, higher rates of illness after the procedure, while maintaining
acceptable costs for people suffering from moderate to severe chronic obstructive
pulmonary disease (COPD)? Background BLVR procedures are a collection of innovative
non‐surgical procedures that aim to improve the disease status and lung function of
participants suffering from moderate to severe COPD, specifically those participants
who remain limited despite conventional treatment. Study characteristics Fourteen
studies including 1979 participants were identified up to December 2016 which studied
BVRs (AeriSeal, airway bypass stents, endobronchial coils, endobronchial valves, intrabronchial
valves and vapour ablation). Most studies compared a BLVR procedure to optimal medical
care or to sham bronchoscopy, while one studied a specific way to place intrabronchial
valves: unilaterally or partial bilaterally. Key results Evidence for short‐term improvements
in disease status were most evident for studies testing endobronchial valves (five
studies) and endobronchial coils (three studies), including improvements in lung function
and quality of life. Improvements in lung function and quality of life were also found
for vapour ablation and AeriSeal, but the quality of that evidence is limited as the
study on vapour ablation was small and the study on AeriSeal was terminated early.
Neither airway bypass stents (one study) nor partial bilateral placement of intrabronchial
valves (two studies) seemed to lead to significant changes in health outcomes, although
unilateral placement of intrabronchial valves did lead to better health outcomes as
assessed by a small study. Studies that found improvements in health outcomes also
found higher rates of potential complications as a result of the procedures, but the
current studies did not provide evidence for a higher risk of death after BLVR procedures,
although the evidence from the included studies is not conclusive. Quality of the
evidence The lack of sham bronchoscopy or unclear status of blinding in some studies
caused a risk of bias for subjective outcomes (e.g. quality of life and exercise capacity).
The lack of long‐term follow‐up, small size of some of the studies, differences in
results between trials, and lack of cost‐effectiveness data limits the quality of
evidence provided in this review.