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Fay Sherret’s heart operation was supposed to extend her life. Instead, a machine used during the routine elective procedure cut it short.
A serious design flaw, known to the manufacturer, allowed the water tanks in the 3T Heater-Cooler, a device that cooled her blood during the surgery, to fill with Mycobacterium chimaera, a lethal bacterium.
A second flaw, not understood until later, then caused the device to spray the contaminated water as a deadly mist into the chest of the 83-year-old former nurse during her heart valve replacement surgery.
Eighteen months later, Sherret was dead, after the bacteria took hold in her heart and ravaged her body.
Three other Australians died from infections linked to the machines between 2016 and 2022.
Australia’s medical devices regulator briefly suspended the machines.
But after design fixes were made, it allowed them back on the market, where they have remained. The regulator instead cancelled the registration of four heater-coolers not linked to the scandal.
The fixes, approved by the Therapeutic Goods Administration (TGA), do not appear to have worked, an investigation by this masthead reveals.
The Medical Malfunctions investigation used automated website scrapers to crack open the TGA’s database to extract about 81,000 publicly available reports detailing adverse-event reports submitted to the regulator since 2012.
Medical Malfunctions has already highlighted issues with the operation and regulation of portable defibrillators that ambulance services distribute to volunteers, glucose monitors and insulin pumps used by hundreds of thousands of Australians, and spinal pain pumps.
Between 2021 and last year, the TGA received 22 reports of contaminated 3T devices. In four cases, the reports said patients were infected and, in one case, the patient died.
“I hold the Therapeutic Goods Administration, the device manufacturer and the [Prince of Wales] hospital [in Sydney] equally responsible,” said Fay Sherret’s daughter Fiona, who has spent the past decade trying to understand what went wrong in the 2015 operation. “The device should be banned.”
The TGA notes that an adverse event report, which can be submitted by a patient, health professional or any other member of the public, does not mean the device caused the event. Nor can such a report be used in isolation to assess the safety of a medical device.
LivaNova, the manufacturer of the devices, says design updates have mitigated the risk. It said the bacteria was found in other places in hospitals, including in operating theatres, suggesting that could have been the source of Fay Sherret’s infection.
Yet, experts say regulators should admit the 3T devices are fatally flawed and should be removed from operating theatres.
“There is a very serious risk of a very serious disease that is very difficult to cure associated with the use of these machines,” said Jakko Van Ingen, head of the mycobacteriology reference laboratory at Radboud University Medical Centre in Nijmegen in the Netherlands and one of the first to discover the infection risk from the devices.
“The risk is real,” he said. “It’s a terrible disease, and it’s very difficult to cure. If someone is infected, it’s an absolute nightmare.”
Before a surgeon begins the delicate task of prying open the chest to get to the heart, they cool the patient’s body.
Typically, humans run about 37 degrees. By cooling the body and blood a few degrees, everything is slowed down. The organs demand less oxygen. A crucial safety buffer is created for the surgeon.
In Australia’s operating theatres, this cooling is predominantly performed by the simple, squat, water-filled machine LivaNova 3T. Blood flows in, runs through cooling coils, and then flows back to the patient.
That water should never come in contact with the patient.
But a crucial design flaw in the 3T allows that water to become contaminated by a deadly bacterium. In rare cases, a fan on the device then turns the contaminated water into a fine mist, which can float down into the patient’s open chest. If the bacteria then take hold in the heart, half of the patients die, according to the TGA.
Dr Simon Moten, spokesman for the Australian & New Zealand Society of Cardiac & Thoracic Surgeons, said: “They are genuine concerns. The risk is extremely small. But because these machines sit in the backroom overnight, or are not used for a period of time, there is the potential for any contamination in those water tanks to multiply.”
‘A perfect storm’
In 2015, contaminated units were discovered across Australia. In 2016, patients started to fall sick. Eleven were eventually infected by the devices – and four died.
In a statement to this masthead, 3T’s manufacturer, LivaNova, said that following upgrades to design and disinfection protocols, its heater-coolers had been validated by regulators around the world.
“LivaNova is aware of very rare allegations of patient infection following surgery by a device updated with its design upgrades and, in these cases, the company has not confirmed that the instructions for use were followed,” it said. “LivaNova is unaware of any reports of patient infection associated with an upgraded device in Australia.”
The story of the upgrades the company refers to starts in 2008 with a 55-year-old man admitted to a Zurich hospital to have a heart valve replaced – the same operation as Fay Sherret’s.
Three years after the operation, he was back again, struggling to breathe. He reportedly explained he had struggled with on-and-off fevers and weight loss for a year that his doctors seemed unable to treat.
The surgeons opened his chest, and discovered his tough artificial heart valve was disintegrating. Despite their best efforts, he died 15 days later from progressive heart failure.
Tissue taken from his heart showed inflammation, dead tissue, and an acute bacterial infection. The bacterium responsible, Mycobacterium chimaera, was an unlikely culprit: common in tap water and soil, weak and slow-growing, and generally considered largely harmless.
Similar cases soon emerged across Europe, the US, Asia and Australia.
Investigators soon focused on the 3T heater-coolers in hospital operating theatres. The machines hold several litres of water, which is cooled and heated between 2 and 41 degrees, and kept at room temperature between procedures. They were placed just metres from the patient. Unlike water used during surgery, the water in the machines was not sterile.
That should not matter, as it was never meant to come in contact with patients.
However, as the water is heated or cooled, the tank’s pressure changes, necessitating an overflow tube, through which water can leak, said Van Ingen.
That valve drips onto the machine’s fan, which can spray it – and any bacteria it contains – around the room in a fine mist, he said.
The 3T also has a strong fan that blows directly across the top of the device’s unsealed water tank. The tank’s lukewarm water is perfect for bacterial growth.
Van Ingen described the device’s combined design flaws as a “perfect storm”.
“In operating theatres, you don’t want anything that has a bucket of water in it for this very reason,” he said. “It poses a serious risk. Especially if that system is not completely closed, and if it is close to a ventilator.”
It later emerged 3T’s then manufacturer, the Italian-based Sorin Group, had detected Mycobacterium chimaera in its factory water supply and the 3T’s production line in August 2014, before the major outbreak started. At the time, the company added extra disinfection procedures.
Fiona Sherret claims the Prince of Wales hospital in Sydney did not adhere to these protocols.
In a letter obtained by this masthead, which was sent to another Sydney patient who died following an infection linked to the device, the Prince of Wales said its cardiothoracic unit was of the view in 2014 that the risk of infection was extremely low. It said there was no need for formal escalation to the hospital executive or for water testing.
“It was considered that life-saving cardiac procedures were of overriding importance and far outweighed risk of infection,” it said.
A spokesperson from South Eastern Sydney Local Health, which covers the Prince of Wales, said 3T devices were still approved for use in operating theatres and were maintained in accordance with the national control guidelines.
“No cases of Mycobacteria chimaera infection have been diagnosed in patients who have undergone surgery in South Eastern Sydney Local Health District since these guidelines were implemented in 2016,” the spokesperson said.
Despite instructions to hospitals to regularly disinfect the devices, the bacteria have proven extremely difficult to kill. There have been more than 120 confirmed infections around the world linked to heater-coolers; experts estimate that is probably only a fraction of the true toll, as the disease is difficult to detect and not all countries report cases.
Infections reported in Australia and around the world suggest these changes may not be enough.
Impossible to clean
In Singapore and in Italy, doctors found that all their devices were infected even after they followed the new disinfection instructions.
“This study suggests that manufacturers’ procedures for disinfection are ineffective and/or inadequate,” the Italian doctors wrote in the Journal of Hospital Infection in 2020. They suggested treating the 3T like a “biohazard”.
“Even if you take out the water, apply disinfection, parts of these bacteria will survive,” said Van Ingen. “These mycobacteria are different. They are extremely hardy. They can withstand the chemical stress. They are very, very hard to kill. Once they are in there, it is extremely hard to get them out.”
A former infection control specialist at a major hospital, who declined to be identified, said the devices appeared extremely difficult to keep clean.
“It’s hard to clean them. And it’s hard to keep them dry. I can understand why they keep growing the mycobacterium,” she said. “When I looked at it, I thought, ‘God, you could never clean this thing properly.’ It had connections you couldn’t take apart. You couldn’t get into the right angles.”
Professor Paul Griffin, an infectious diseases physician at Mater Health Services, and one of the first scientists to identify the outbreak in Australia, said the machine had a “fundamental flaw”.
“With all that undertaken, the fact we’re still seeing cases, it would suggest there is not a definitive solution. We need to reconsider how we use these machines, find an alternative, or completely redesign them.”
LivaNova disputed there were flaws in the cleaning instructions.
“LivaNova conducted comprehensive validation studies demonstrating that this process effectively and consistently maintains the required water quality when the instructions for use are followed,” the company said in a statement. “The vacuum and sealing design upgrade has been demonstrated to be highly effective in containing any potentially contaminated aerosols generated from the device water, thereby preventing possible patient infections.”
‘This is so humiliating’
It took almost a year for Fay Sherret to realise she was sick. In late 2016, the previously chirpy and active woman, who enjoyed walking, catching up with friends and playing bridge, began having fevers and shaking uncontrollably. She was also confused.
“I’d never seen her like that before,” said her daughter Fiona, who caught a taxi with her mother to St Vincent’s emergency department in Sydney’s eastern suburbs in December 2016.
As doctors tried to grow a culture from Fay’s blood, Fiona went home and discovered the cause of her mother’s death.
A letter from the Prince of Wales hospital, sitting in Fay’s letterbox, said there was a one in 10,000 chance Fay had been infected by the deadly bacteria.
Following her diagnosis, Fay spent nine months in and out of hospital battling the infection that was ravaging her new heart valve. She was pumped with potent antibiotics and had a failed secondary surgery to replace her damaged valve.
After contracting pneumonia, she was intubated because she was struggling to breathe. Before she died in July 2017, Fay turned to her daughter and whispered: “This is so humiliating.”
“She had become pretty much incapacitated by the infection,” Fiona recalled. “She had maintained relatively good health and the infection destroyed that.”
Following Sherret’s case, investigators soon established the infection was nearly everywhere in Australian hospitals: 43 units tested positive across four states, as did five patients. One patient had the bacteria in his bone marrow.
In total, 25 per cent of Australia’s fleet of 3Ts tested positive.
LivaNova – the device’s current owner – settled a $US225 million ($323 million) lawsuit in America over the devices in 2019. A lawsuit in Canada is ongoing.
Following the outbreak, the TGA reviewed surgical heater-coolers, which led to the registration of four devices being cancelled.
A regulator’s spokesman said the sponsors for the cancelled heater-coolers “did not provide the TGA specific information or samples” the agency had sought.
Six different types of heater-cooler remain registered – including, crucially, the 3T, the device responsible for nearly all infections from heater-coolers globally.
It was allowed to remain on the market after the manufacturer’s new sealing and cleaning instructions were added.
The TGA has advised hospitals to stop using Sorin devices manufactured before September 2014, when the new disinfection protocols were issued. But NSW authorities last year found an infection in a new machine.
The TGA spokesman said the agency “continues to closely monitor the situation involving Mycobacterium contamination associated with heater-cooler devices and will undertake additional regulatory action if appropriate”.
A LivaNova spokesman said the machines “may be contaminated by environmental factors related to the specific clinical practice and setting, including failure to follow instructions for use”.
“LivaNova’s protocol, if properly applied, effectively controls contamination, as demonstrated by validation carried out in collaboration with third parties and accredited laboratories.”
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