Stöckert 3T Heater-Cooler Devices
Patients who have recently undergone cardiothoracic (open-chest) surgery in which a Stöckert 3T Heater-Cooler system (“3T HCU”) was used should be aware of a potential infection risk that has been linked to this device.
On October 13, 2016, the Food and Drug Administration (FDA) released a safety communication warning doctors and hospitals that surgery using these devices had been linked to Mycobacterium chimaera (M. chimaera) infections. These are dangerous infections that can cause serious illness and even death.
According to The Washington Post, M. chimaera infection outbreaks have been identified at hospitals in Iowa, Michigan, and Pennsylvania, with at least at least 28 cases identified in the past year. More have been reported in patients in Europe and around the U.S.
The FDA has warned doctors and hospitals to immediately remove any of these devices that test positive for the bacteria from their facilities. The medical community was also told to consider limiting the use of these devices until the manufacturer has found a way to mitigate the risks of patient infection.
Patients, meanwhile, should watch for potential symptoms of infection, including persistent fatigue, fever, and muscle pain.
What are Heater-Cooler Units?
Heater-cooler units (HCUs) (also called heater-cooler devices or HCDs) are medical devices that are used during cardiothoracic surgeries, including open-heart surgery, coronary artery bypass surgery, heart valve surgery, and lung transplant surgeries. They are designed to help keep the patient’s organs and circulating blood at normal temperatures during surgery.
These devices have water tanks that provide temperature-controlled water to external heat exchangers or warming or cooling blankets through closed circuits. Though the water never comes into contact with the patient, the devices have fans and exhaust vents. Contaminated water from inside the device can aerosolize as it travels through the closed circuits. That contaminated air can then be pushed into the operating room through the exhaust vents where it can contaminate the patient undergoing cardiothoracic surgery.
The Centers for Disease Control and Prevention (CDC) estimates that more than 250,000 heart bypass procedures using HCUs are performed in the U.S. each year. HCUs are used during these procedures because they keep the patient’s circulating blood at a safe temperature while the beating of the heart is temporarily stopped.
What are Stöckert 3T Heater-Cooler Units?
Stöckert 3T HCUs represent about 60 percent of the U.S. market for heating-cooling units. They have been available since 2006, and are manufactured by Sorin Group USA, Inc. and LivaNova Group Deutschland GmbH (collectively “manufacturer”). The FDA estimates that there are currently around 2,000 of these devices in use in the U.S.
The manufacturer advertises the devices as efficient heating and cooling machines. It promotes the devices as having compressor-based cooling and three independent water tanks and eliminate the need for ice and water supply in the operating room. And touts that the devices’ temperature settings “can be adjusted to the tenth decimal point for accurate temperature control.”
On October 13, 2016, in response to the FDA and CDC warnings, the company released a “field safety notice update” warning surgeons and hospitals of potential risks associated with the machines. The manufacturer also claimed that it had “learned a great deal” over the past two years about the infection risk to open-heart surgery patients.
The manufacturer acknowledged that the CDC confirmed with laboratory testing that the M. chimaera found on certain 3T HCUs showed a “genetic similarity between both patient and heater cooler strains of the NTM bacteria M. chimaera isolated in Iowa and Pennsylvania.”
The manufacturer further noted that it was “continuing to analyze” the data, would work with the CDC and FDA to facilitate their recommendations for reducing the risk, and would “develop solutions to further mitigate the potential risk of NTM contamination.”
Heater-Cooler Devices Increase Risk of Infections
M. chimaera is a type of nontuberculous mycobacterium (NTM), which is classified as “slow-growing” bacteria. These organisms occur naturally in the environment and are found in water and soil. They are usually not dangerous to humans unless they are inhaled or if they enter the chest or lungs in another way, such as during surgery.
In most people, the organisms are cleared from the lungs naturally and don’t cause infections. But, the risk of infection is greater for people with weakened immune systems or who undergo these types of open heart surgeries. The CDC has reported that patients who had valves or prosthetic products implanted are also at a higher risk.
In a 2016 study, researchers identified HCUs as the source of Mycobacterium chimaera causing surgical site infections. They used a thermic anemometer and particle counter to track the transmission of the bacterium in an operating room. The culture samples taken from less than five meters from the unit tested positive for M. chimaera. The results confirmed that “airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation.”
In another 2016 study in Europe, researchers found a link between the M. chimaera samples taken from several infected patients, from the HCUs used during their procedures, and from environmental samples from Sorin’s HCU manufacturing and servicing facility in Germany. Researchers concluded that at least some of the M. chimaera infections may have been caused by HCUs that were contaminated at the manufacturing site.
Heater-Cooler Infections are Serious and Can Be Deadly
NTM infections are particularly dangerous because they’re slow growing and can take months or even years to manifest symptoms. The CDC warns that patients who have been exposed through open-heart surgery can “develop general and nonspecific symptoms that can often take months to develop.”
That means that diagnosis can be missed or delayed, sometimes for years. During that time, the bacteria continue to grow. By the time the infection is finally diagnosed, it is usually more difficult to treat because of the delay.
So far, there is no blood test or other type of medical test to determine that a person has been exposed to the bacteria. There is a specific test that doctors can give to diagnose an M. chimaera infection. Traditionally, however, most hospitals do not perform this specific laboratory culture in the normal course of treating an infection. And if it is done, it takes months for the bacteria to grow enough for the culture to detect the infection.
Since 2010 or earlier, the manufacturer has been aware of infections and even deaths linked to these devices. Between January 2010 and February 2016, the FDA received 180 incident reports related to HCUs around the world. A total of 16 U.S. hospitals across ten states, were implicated in these reports, where at least forty-five patients were infected and at least nine died.
Consumer Reports noted that in 2014 at Greenville Memorial Hospital in South Carolina, officials identified at least 15 patients who were diagnosed with rare infections after heart and lung operations. Four of them died. An investigation traced the infections to the HCUs used in the operations.
Most of these infections have been linked to the Sorin Stöckert 3T HCU, which is manufactured in Europe.
The FDA and the CDC caution that patients who have had open-heart surgery should notify their doctor immediately if they experience any of the following symptoms:
- Night sweats
- Muscle aches
- Weight loss
- Unexplained fever
- Difficulty breathing
- Persistent cough or cough with blood
Other infection-related complications that can occur up to years after surgery include:
- Surgical site infection
- Endocarditis (inflammation of the inner lining of the heart)
- Bacteremia (bacteria in the blood)
- Osteomyelitis (inflammation in the bone)
We’ve put together this timeline to highlight the potential link between 3T heater-cooler devices and nontuberculous mycobacterium infections:
Use the arrows on the left and right side of the timeline slideshow to navigate through its progression.
FDA Tracks Problem of Stöckert 3T Heater-Cooler Device Infections
The manufacturer has known of HCU-related infections for some time. The FDA received the first incident report of an infection in 2010. In 2015, investigators in Switzerland reported that six patients developed M. chimaera infections after going through open-heart surgeries in which contaminated HCU devices were used.
In June of that year, a Pennsylvania hospital identified a cluster of NTM infections among open-heart surgery patients. Investigators working with the CDC identified an association between the infections and exposure to a contaminated Stöckert 3T HCUs. That investigation prompted the hospital to notify 1,300 patients that they may be at risk of developing an infection because of a device used in surgery.
Subsequent tests of the devices, together with the report from Germany noted above, suggest that the device contamination had come from the 3T HCU manufacturing site. Additional, the CDC reports that comparisons between patient specimens and device samples from facilities from various regions of the U.S. are “ongoing”.
In October 2015, the FDA released a safety communication warning that the use of HCUs had been associated with NTM infections, “primarily in patients undergoing cardiothoracic surgical procedures.” In some cases, patients presented with infections “several months to years after their surgical procedures.” The FDA recommended that facilities and staff strictly adhere to cleaning and disinfection instructions, and to use only sterile water to rinse, fill, or refill the tanks.
The company also notified hospitals around this time, and disseminated updated cleaning instructions for the devices. The revised instructions were later found to be inadequate in reducing risk of infections.
In December 2015, the FDA issued a warning letter to the manufacturer after inspections of several of their facilities revealed significant problems, including quality system and premarket clearance violations. They also placed an import alert on the devices to restrict how many devices come into the U.S.
In June 2016, the FDA released an updated safety communication in which it warned of potential infections associated with the use of the Stöckert 3T HCU. It also revealed that testing by the manufacturer back in August 2014 found M. chimaera on the production line and water supply at the 3T manufacturing facility. In response, the company added new cleaning and disinfection procedures to the production line in September 2014. Samples taken in June 2015 did not show bacterial contamination.
The FDA noted that facilities that had purchased and used the 3T prior to September 2014 should be aware that the units may have been shipped from the factory contaminated with M. chimaera.
A few months later, in October 2016, the FDA released another safety communication, warning health care facilities to take additional steps to help mitigate the risk of infections associated with 3T HCUs. Specifically, it recommended that any facility with devices manufactured prior to September 2014 should “strongly consider transitioning away from the use of these devices for open-chest cardiac surgery until the manufacturer has implemented strategies for these devices to mitigate the risks of patient infection.”
The FDA noted that it was continuing to evaluate infections associated with HCUs, primarily in patients undergoing open-heart surgery. And noted that it was still working to determine the cause of these infections, one of which may be the heater-cooler design.
Stöckert 3T Heater-Cooler Device Lawsuits
Patients who had cardiothoracic surgery and then suffered a serious infection may be eligible to file a Stöckert 3T Heater-Cooler device lawsuit.
Patients may be unaware of which device was used in their surgery. Chaffin Luhana provides consultations and case evaluations to help determine which device was used, and whether patients may have a case against Sorin Group USA, Inc. and LivaNova Group Deutschland GmbH.
Call today at 1-888-316-2311.