The evolution of the bronchoscopy: diagnostics and breakthrough treatments

Professor Pallav Shah
By Professor Pallav Shah     05/07/2018

As a consultant physician in respiratory medicine with a specialist clinical interest in bronchoscopy, I treat patients with many different lung conditions.

A bronchoscopy is a test that uses a tube to examine the airway and lungs to help with diagnoses; increasingly, this procedure is used to deliver treatment for respiratory conditions.

I sometimes joke I’m a ‘jack of all trades’ – the advantage of the way I work is I have a very broad overview.

During the past 70 years, advances in bronchoscopy have been transformative in respiratory medicine. The evolution of this surgical tool has brought innovations and new treatments at an astonishing rate.

Even the amount of technological leaps that I have witnessed in just the last decade is phenomenal.

The second revolution of bronchoscopy

When the NHS was founded in 1948, a bronchoscope would literally have been a rigid metal tube, with no flexibility. It was inserted into the airways, through the mouth. Patients who needed a bronchoscopy would have all been given general anaesthetic.

These rigid bronchoscopes had been used since their invention in 1897. But things were about to change.

In fact, Royal Brompton Hospital was the first hospital in the UK to introduce flexible bronchoscopy, around 1974 by Dr Stewart Clarke.

This flexible tube made a huge difference to patients who needed the procedure. For a start, it meant that they only needed a local, rather than a general anaesthetic. This in turn meant the procedure could be done as a day case: patients no longer needed to stay in hospital overnight.

Primarily, these flexible bronchoscopes were used for cancer diagnoses, or if we suspected there was infection such as TB.

Using bronchoscope technology to actually treat patients, rather than purely for diagnostics, was not to come until years later.

Diathermy and bronchoscopy

Technology remained at that level through the ‘80s and ‘90s.

It was then a group of doctors including myself, Thomas Sutedja (Amsterdam) and Richard Lewis from Worcester, started to look at diathermy.

This is a surgical technique which had been helpful in gastroenterology. It involves the production of heat in a part of the body by high-frequency electric currents, to stimulate the circulation, relieve pain, destroy unhealthy tissue, or cause bleeding vessels to clot.

We simply adapted by using the same tools through the bronchoscope to treat tumours in the trachea and major bronchi.

Endobronchial ultrasound

The next breakthrough was the endobronchial ultrasound: this describes a procedure where we attach a chip to an ultrasound probe; this was incorporated into the camera so you could see outside the airways.

This was important – for the first time we could send a probe to visualise structures adjacent to the airway wall, helping give swift diagnosis to conditions such as lung cancer.

Working with Japanese doctors, Mark Krasnik in Denmark and Felix Herth in Heidelberg and myself, spent three or four years developing a prototype.

Endobronchial ultrasound came into commercial use in 2004. Within five years, 70 centres in the UK were using the technology.

It allowed us to sample lymph nodes and tumours adjacent to the airways in a minimally-invasive way. We could avoid complex surgery requiring general anaesthetic.

Globally, endobronchial ultrasound has been utilised in two million procedures and has made the patient’s journey a lot easier.

From the perspective of the NHS, this has meant we can do four or five of these procedures in a morning, as opposed to having a patient come in for a general anaesthetic and require a bed for longer.

Emphysema and new approaches

Emphysema is a debilitating lung condition typified by shortness of breath and coughing. Those with emphysema struggle to do mundane tasks, or even walk a few steps.

It’s caused when the air sacs are weakened; old air becomes trapped, stopping fresh oxygenated air entering. Triggers and causes include smoking and pollution.

When it comes to treating emphysema, there have been huge changes.

Over the years, surgery has had varying results. In the late ‘50s, doctors begun to realise the answer could lie in the somewhat counter-intuitive move of reducing the volume of the lung. The theory was the damaged portions of the lung became baggy with old air. Reducing the space in the lung means the healthy parts of the lung have more room to expand – it makes the lung become more efficient.

This worked – but results were hit and miss. The big problem with surgery was that patients were at risk of a punctured lung, and ending requiring ventilation in intensive care.  We needed to try and do it in a way that didn’t involve the same risks.

A surgeon in the midlands had patented a system for blocking the damaged parts of the lung. The idea needed refining – his concept was to have a sponge-like device hooked into the lung to block the damaged part.

Royal Brompton Hospital bought the patent and sold it to a US technology company called Emphyasis and subsequently by Pulmonx.  In conjunction with them, we developed endobronchial valves; they allow air to come out, but not air to go back in. The damaged portion of the lung then shrinks. This improves the working of the diaphragm and breathing, and the lung also acquires a better overall shape.

Globally, there have been five randomised studies into endobronchial valves. There are two more studies to come. So far, they all show that patients having the procedure see an average lung function improvement of 20 per cent. These are patients with emphysema and already taking the most appropriate treatment for the condition.

Before this treatment, these patients would simply have run out of options, suffering severe breathlessness and diminished life expectancy.

The valves are only suitable for certain patients, those with isolated lobes – so that air doesn’t the lobe through other routes – however, the success of these valves has inspired us to look at how we can do things differently.

Endobronchial nitinol coils for example, have also been effective. We put 10 or 12 coils which are made of nitinol, a shape memory alloy, into each lung. When in place, the coils gently regain their shape, gathering up loose, inelastic lung tissue and holding open surrounding airways. The coils restore elasticity to the lung allowing patients to breathe out efficiently.

We started trials in February 2010 and published our results in 2013 in The Lancet Respiratory Medicine Journal. Our research showed patients had improved lung function by about 15 per cent. This meant they were walking about 50 metres further every day, with a dramatic improvement in their quality of life. Similar results have been reproduced by other researchers.

We have also used steam treatments to ablate the lung using the same underlying idea, although we are quite cautious because sometimes there’s an over-exuberant scarring response.

We carefully decide which treatment option is best for each patient. 

Smooth muscle and asthma

With asthma, the bronchoscope has enabled the development of the bronchial thermoplasty; we were involved in the clinical trials. 

The smooth muscle in the airways of asthma sufferers is usually thicker than those without the condition and so when it contracts it significantly restricts the airway.

We use a special catheter via bronchoscopy to use electrical/radiofrequency energy to zap the smooth muscle in the airways of the lungs. We apply heat at 65 degrees centigrade to destroy the smooth muscle in the airway wall.

This procedure destroys this excess muscle and so helps patients’ airways stay open during an asthma attack.

We systematically treat the whole airway in three stages as the lung is so diverse, waiting a few weeks in between.

Clinicians are seeing incredible results; research has shown that bronchial thermoplasty can almost halve the number of severe asthma attacks and cut the average number of emergency hospitalisations in treated patients by over 80 per cent.

Since 2010, 2,500 patients worldwide have undergone bronchial thermoplasty to deal with their asthma.

The next frontier

Our latest trials, Airflow 1 and Airflow 2 have been looking into vagal ablation for COPD (Chronic Obstructive Pulmonary Disease, the umbrella term for progressive lung diseases).

We have been treating the vagal nerve, the longest cranial nerve which runs through the neck and thorax to the abdomen; it contains nerve fibres supplying energy to different organs.

Theoretically, the idea is simple: the nerves cause contraction of smooth muscle, triggering mucus production and causing asthmatic attacks. Take out some of the nerves and you induce resting status, preventing this from happening.

We do this via radiofrequency catheter. The results are very encouraging – patients who have undergone the procedure show greater improvements experienced on the existing medication.

When patients are given the drug in addition to the treatment, the results are boosted further. It really does open up the airways meaning the drugs can get further into the patients’ lungs and thus making them more effective.

Now we’re about to start on Discovery, the third clinical trial.

We’re also looking into cryotherapy to treat lung conditions. We use liquid nitrogen, which basically freezes specific sections of the airway to about minus 297 degrees centigrade.

Liquid nitrogen expands to 7,000 times its volume when it becomes a gas, so it’s something we’re handling with extreme care and the dose we give is tiny. Cryospray treatment for chronic bronchitis treats the affected epithelium and allows new cells to regenerate from the stem cell. Thus far there have been no effective therapies for chronic bronchitis.

Working at Royal Brompton Hospital is a privilege. We are like a family – we all have the same ethos, which is to strive for excellence and compassionate care of our patients. 

There’s an almost invisible quality which make it a pleasure to work for; this special quality makes me really want the hospital to do well. 

I first started here in 1991 and I have never looked back. I have had some great mentors from Professor Sir Magdi Yacoub, to Professor Duncan Geddes, Professor Margaret Hodson, Dr John Collins and Professor Sir Anthony Newman-Taylor. I learned so much from them and hope I can achieve a fraction of what they achieved.

There are lots of things to get excited about. We’ve had a brilliant ten years and I believe we are on the verge of even greater discoveries in the future. 

Professor Pallav Shah is a consultant physician in respiratory medicine at Royal Brompton Hospital and Chelsea & Westminster Hospital.