When every minute counts

It has been two years since Melbourne stroke experts published their revolutionary advances in stroke care as part of an international trial to physically remove blood clots deep inside the brain. Here, we hear of the latest efforts to push the technique further.

It has been two years since Melbourne stroke experts published their revolutionary advances in stroke care as part of an international trial to physically remove blood clots deep inside the brain. Here, we hear of the latest efforts to push the technique further.

her via videolink and reviewed her brain scans to give her the go-ahead to receive a thrombolysis injection to help dissolve the clot in her brain.

He also arranged her urgent transfer to Melbourne for endovascular clot retrieval – a procedure to manually remove the clot. Fortunately, this was not required as the drug dissolved the blockage en route.

The telemed program, devised and run by the Florey, now covers 16 hospitals to ensure 94 per cent of Victorians are within one hour of expert stroke care.

Having now treated more than 1400 patients through the telemedicine service, it continues to set records; clocking up 12 consultations and three thrombolysis cases in one weekend in March.

Co-leader of the program, Professor Christopher Bladin says the team is planning to extend the telemedicine service interstate and establish the Australian Telemedicine Network.

They are working to end the “postcode lottery” of health care for the 55,000 Australians who have a stroke each year.

“The grand aim is that no stroke in Australia goes untreated,” Chris says.

“About 5-7 per cent of patients are being treated with thrombolysis. But that should be up around 10-15 per cent.”

“Time is brain with stroke. For every minute faster you get stroke care, you save one day of life free of disability.

“In Victoria we can now honestly say no matter which postcode you’re in, whether it’s 3km from a metro hospital or 300km from Melbourne, you will get the same international stroke experts treating you.”

Caitlyn is now back at school full-time and is still being treated for the cardiac virus that caused her heart attack, which led to the stroke.

“I’ve got a little bit of rehabilitation to go on my hands, like I couldn’t tell if I was holding something fluffy or something rough, but I’m nearly there,” she said.

“I just feel very, very lucky.”

Fast facts

Researchers, led by the Florey’s Director Geoffrey Donnan, are preparing to further the success of the minimally invasive clot retrieval procedure to make it safer and more effective. The earlier it is offered, the more precious brain cells are saved.

Every minute’s delay in seeking medical treatment after stroke costs millions of neurones. These new developments can mean the difference between someone returning to independent life after stroke or being left significantly disabled.

Geoff says it had long been known that blood clots in a large artery of the brain were the cause of ischemic strokes, which make up 80 per cent of all strokes.

If the clot can dissolve, then blood flow to the brain can return and compromised brain tissue can be potentially salvaged.

While a proportion of clots dissolve on their own – often as patients are mid-flight in the air ambulance on route to the Royal Melbourne Hospital for this endovascular stent thrombectomy – for a large proportion of patients, their clot is too large and the artery remains blocked despite receiving the clot-busting medication tissue plasminogen activator (tPA).

A global race began to design a device that would manually remove the clot and restore blood flow safely.

Clinical trials started around the world using various models of clot retrieval devices, but were unsuccessful in showing they could advance stroke care. Not only were there problems in the devices’ design, but these studies didn’t use advanced imaging to ensure their enrolled patients even had salvageable brain tissue to begin with, as well as having low rates of reperfusion after retrieval.

“It’s a difficult ask because the device has to completely extract the clot whole, without breaking it up,” Geoff says. “It’s very difficult to design equipment to do that.”

A spring-loaded device developed in the US to put coils on aneurysms, similar to a stent used in coronary heart disease, emerged as a promising option.

Melbourne was one of five international centres to trial the device in a study with the Royal Melbourne Hospital involving project co-chair Director of Neurology Professor Stephen Davis, neurologist Associate Professor Bruce Campbell and Director of The RMH’s neurointervention program, Professor Peter Mitchell.

What set the Melbourne collaboration apart was the strict criteria they use for selecting which patients could receive the experimental procedure. X-ray perfusion imaging has allowed them to select those patients who still had a large portion of surviving brain tissue.

This type of advanced imaging uses an automated software program to give clinicians a much more accurate snapshot of the difference between salvable brain tissue and irreversibly damaged regions to select the most appropriate patients.

The procedure, known as stent thrombectomy, involves inserting a small tube into an artery in the groin, and threading up the wire-cage stent device to the brain to grab the clot and remove it in one piece.

“We were able to demonstrate it was very, very effective,” Geoff says.

“It gave patients more than three times the chance of getting up and walking out of hospital, compared to just using the clot-busting drug. It is incredible.

“It has changed practice around the world, having a huge effect on how we deliver patient care.”

The results were published in early 2015 in the prestigious New England Journal of Medicine.

In just the past 12 months, the RMH has performed this procedure on more than 200 people.

Inspired by the results, there was a collective team brainstorm: how could they bring this life-changing procedure to a broader range of people, faster and with fewer complications?

They are now considering whether endovascular clot retrieval can be used as the first-line treatment, bypassing the need for tPA. This means patients could have their clot retrieved at least 30 minutes earlier, as well as removing the need for tPA which increases the risk of post-stroke bleeding.

The team is now combing patient data from all the five international trials to uncover if there are clues in patient histories and outcomes that can indicate which patients will benefit.

“It might be that we could look at patients with a slightly longer time window.”

“Theoretically we might be able to operate up to six hours after the stroke, but we’re not quite sure yet. Perhaps we can offer it to patients who have less surviving brain tissue and they still might benefit.

“We’re planning that trial right now.”

With RMH and Monash Medical Centre now equipped to perform the procedure, Geoff predicts it will not take long before the technique is offered more broadly at major hospitals thanks to the pioneering work that has established the safety and efficacy of this treatment.

“Every minute counts with stroke. We lose about two million brain cells per minute once the process has started. This is all about getting people treated as quickly as possible, so more people are walking out of hospital doors, going home after a stroke.”