COPD

Pint-size valve making a big mark


A tiny one-way valve is making a huge difference to the quality of life of thousands of people living with COPD across the globe.

And Australia has been leading the way in the use of endobronchial valves, ever since the world’s first valve, made by interventional pulmonology company Pulmonx and known as the Zephyr®EBV,  was implanted into a patient in Australia some 12 years ago.

More than a decade may have passed since then, but research continues to support the valve’s role in providing measurable clinical benefit to patients with severe emphysema – and importantly significant improvements to quality of life, exercise capacity and lung function.

Simple ideas are sometimes the most effective

Senior Thoracic Physician, Associate Professor Alvin Ing is regarded as a pioneer in this field, and was among the first to carry out the procedure, which involves the implantation of the tiny one-way valves into the lungs to block airflow to diseased regions.

“It’s a simple idea, but sometimes the simplest ideas are the most effective,” he said.

He remembers that patient well as a man with emphysema and a lung function of about 30%.

“He went on to do very well,” he says. “His lung function improved by about 35% and his six minute walk test improved by 35 to 40%.”

Professor Alvin Ing is an Associate Professor of Medicine at the Macquarie University, a senior thoracic physician at Concord Hospital and the Chair of Thoracic Medicine at the Sydney Adventist Hospital, where he is also one of the foundation academics at the Sydney Medical School.

He has long had a strong interest in COPD and has been involved in interventional pulmonology since 1993, when he helped establish endobronchial laser resection and stent deployment at Concord Hospital.

Endobronchial valve (EBV) valve therapy has come a long way

He was also instrumental in establishing endobronchial ultrasound (EBUS) at Concord Hospital and has worked with and extensively researched Endoscopic Lung Volume Reduction (ELVR).

Endobronchial valve (EBV) therapy has come a long way since the early days and physicians have been able to learn which patients will do best from the therapy, he says.

Professor Ing estimates he has carried out just under 200 procedures since 2007.

“There has been major progress,” he says. “We’ve learned a lot in the past eight years.”

Gaining acceptance from the respiratory specialty community has been one of the key developments.

“There is a general acceptance now that this is an acceptable therapy for end-stage COPD,” he says.

“We now know who to do and who not to do, and we have refined the procedure to minimise complications and improve outcomes.”

He says the patients most suited to valve therapy are those with heterogeneous emphysema and complete fissures.

“It is a great alternative as it gives a similar result (to surgery) without the major complications of surgery,” he says.

What the evidence says

EBV therapy is also gathering strong momentum from ongoing research, including a paper published late last year in the New England Journal of Medicine supporting this.

The STELVIO trial studied 68 patients who were considered for the EBV therapy using a specialised assessment system, also developed by Pulmonx and known as the Chartis Pulmonary Assessment System.

These patients were confirmed to be likely responders to EBV therapy, and randomised to either EBV therapy or medical management.

“Endobronchial-valve treatment significantly improved pulmonary function and exercise capacity in patients with severe emphysema characterized by an absence of interlobar collateral ventilation,” the study authors concluded.

Dr Matt Bayfield, cardiothoracic surgeon at Sydney’s Royal Prince Alfred Hospital and another early user of the therapy, says the NEJM study reinforces the potential benefits for Australian patients with severe emphysema.

“In Australia, established treatment options for severe emphysema have typically included inhaled medicines and pulmonary rehabilitation,” he says. “Although a surgical treatment option is available for some of the emphysema population, it is perceived to carry more risk”.

“The NEJM study results demonstrate that the use of one-way endobronchial valves should also be considered as a viable treatment option for Australian patients with severe emphysema.”

Professor Ing agrees, describing the NEJM article as a “nice cross-over study that showed the significant benefits” of EBV therapy.

“It’s good to get it published in a journal like the NEJM,” he says.

The use of EBV therapy was also examined in an expert statement published in the International Journal of Thoracic Medicine Respiration.

This article studied the available techniques for ELVR, which is emerging as an effective alternative to lung volume reduction surgery, which the authors pointed out had “shown a beneficial effect in selected patients but is counterbalanced by the morbidity experienced by some patients.”

The technologies examined included endobronchial valves and coils, bronchoscopic thermal vapor ablation (BTVA), and biological lung volume reduction.

They looked at EBV trials to date and found that “evidence is accumulating that with EBV treatment real personalised medicine for the treatment of patients with severe emphysema is possible, with even as high as a 75% responder rate to treatment when using a combined approach for recruiting potential candidates.”

Of all the technologies currently available, the authors concluded that only LVRS and EBV therapy had reached the evidence level to be used outside of clinical trials, although they did describe the new techniques as “solid and promising in creative hands.”

“Current endoscopic developments are significantly progressing…” they wrote “and will for sure add more input to the current algorithm. LVRS is still a valid treatment option; however, nowadays new surgical techniques are available…”

Pulmonx Australia welcomes the NEJM study, says the company’s national business development manager Sarah Coxon.

She notes that “the study demonstrates both statistically and clinically significant outcomes in lung function, exercise capacity and quality of life for severe emphysema patients being treated with EBV therapy”.

“Over the past decade, the technique of bronchoscopic treatment of emphysema has emerged as a viable and mainstream treatment option for selected patient groups”, she said.

The first Zephyr® EBV valve was implanted in Australia over 12 years ago, and since then, over 10,000 patients have been treated with the medical device globally.

How to select patients

In Australia, patient eligibility for EBV therapy can be determined at a number of major metropolitan teaching hospitals* including Royal Prince Alfred (NSW), Royal Brisbane (QLD), Alfred Hospital (VIC) and Royal Adelaide (SA).

“Although mortality rates are declining in Australia, COPD is still a leading cause of death and disease burden after heart disease, stroke and cancer,” Ms Coxon says.

Meanwhile, Professor Ing and his colleagues will continue to use the EBV therapy, while also keeping a close eye on the development of other ELVR techniques, including coils, thermals and biologic reduction.

“I think the valves are pretty well refined now,” he says. “I think that the principal of the therapy was always sound, but it was important to know which patients it was going to work best for, and I think we’ve achieved that.”

He says it is interesting to see that more patients are now seeking out EBV therapy, and while not everyone will be a suitable candidate, it is reassuring to see mainstream confidence in the procedure is growing as well.

“A lot of it is word of mouth and not infrequently referrals are driven by patients,” he says. “It’s always hard to predict how well something like this will go, but there’s no doubt that when lung function improves, quality of life improves and people are seeing the benefits of that.”

*For a full list of Australian treatment centres, please visit: http://pulmonx.com.au/treatment-centres/

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