Endobronchial Coil for Severe Emphysema Can Improve Outcomes

Damian McNamara

May 18, 2016

SAN FRANCISCO — For patients with advanced emphysema and severe lung hyperinflation, the implantation of an endobronchial coil improves some outcomes, according to the RENEW trial.

"These are very ill patients. We need options, even if they are not home runs," said Frank Sciurba, MD, from the University of Pittsburgh.

The coil is a "real chance" for patients with severe emphysema, he told Medscape Medical News. "We need tools like this."

Dr Sciurba presented efficacy and safety results from the intent-to-treat assessor-blinded study here at the American Thoracic Society 2016 International Conference. The study was published online May 15 in JAMA to coincide with the presentation.

The 315 patients in RENEW — Lung Volume Reduction Coil Treatment in Patients With Emphysema — had advanced bilateral emphysema and severe lung hyperinflation. All had completed pulmonary rehabilitation in the 6 months prior to study entry.

The study was conducted by investigators at 26 sites in the United States and around the world.

Mean baseline forced expiratory volume in 1 second (FEV₁) in the study cohort was 25% to 26% of predicted, at least 70% of the patients had very severe emphysema (GOLD stage IV), and about three-quarters of the patients presented with difficult-to-treat homogeneous emphysema.

For the 158 patients randomized to the endobronchial nitinol coil (PneumRx Inc.) implant, a straight coil was deployed through a bronchoscope, which then recoiled to regionally compress the lung. The device, designed to be unaffected by interlobar collaterals, was implanted in the contralateral lung 4 months later.

For the 157 patients randomized to usual care, treatment was in accordance with GOLD guidelines.

The effect size of the primary outcome — change from baseline in 6-minute walk distance — "was modest," Dr Sciurba reported. And "we found a significant difference in all secondary outcomes favoring the coil group."

Table 1. Outcomes at 12 Months

Outcome Endobronchial Coil Usual Care P Value
Change from baseline      
   Median change in FEV₁ 3.8% –2.5% <.001
   Change in residual volume –0.41 L –0.10 L .001
   Mean change in residual volume/total lung capacity ratio –4.0% –0.5% <.001
6-minute walk distance      
   Change from baseline 10.3 m –7.6 m .015
   Responder rate 40% 26.9% .01
St. George's Respiratory Questionnaire      
   Mean change –8.1 0.8 <.001
   Responder rate 61.2% 27.7% <.001


The improvement in quality of life and exercise tolerance weighed against periprocedural adverse events "provides an evidence-based choice for symptomatic patients and treating physicians who have few other options," Dr Sciurba explained.

In the coil group, quality-of-life improvement on the St. George's Respiratory Questionnaire exceeded twice the minimal clinically important difference, he reported.

The frequency of any complication was significantly greater in the coil group than in the usual-care group (34.8% vs. 19.1%), and was "primarily driven by the respiratory infections," Dr Sciurba said. All serious adverse events returned to baseline at 9 to 12 months.

The risk for major complications driven by lower respiratory tract infection was significantly greater in the coil group than in the usual-care group, but there was no difference the in mortality rate, he said.

Table 2. Serious Adverse Events

Event Endobronchial Coil, % Usual Care, % P Value
Pneumothorax 9.8 0.6 <.001
Lower respiratory infection, pneumonia requiring antibiotics or corticosteroids 18.7 4.5 <.001
Pneumonia 20.0 4.5 <.001


Ten patients in the coil group died, and one death was related directly to the coil procedure. Eight people in the usual-care group died.

During the study, the investigators identified a new clinical phenomenon related to the implantation: coil-associated opacities. "We believe a proportion of patients have a noninfectious inflammatory response to the coils, upper lobe contraction, and diaphragm retraction," said Dr Sciurba. Of the 40 investigator-reported cases of pneumonia, 14 (35%) were adjudicated to be coil-associated opacities.

"I'm a little ambivalent," said session moderator Richard Albert, MD, from the University of Colorado Denver. "The improvement in 6-minute walk test is not clinically relevant; however, the improvement in quality of life is clinically meaningful."

"These are end-stage patients. They don't have many options, so if you can improve quality of life with this procedure, it might be worth doing," he told Medscape Medical News.

But the learning curve for placing an endobronchial coil can be steep. "It's not a good idea to do this on the occasional patient," Dr Albert pointed out.

Dr Sciurba reports receiving institutional support from PneumRx and Pulmonx. Dr Albert has disclosed no relevant financial relationships.

American Thoracic Society (ATS) 2016 International Conference: Abstract 2869. Presented May 16, 2016.


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