The Stockert 3T Heater-Cooler, manufactured by LivaNova, has been linked to cases of mycobacterium chimaera, a type of non-tuberculosis mycobacteria (NTM), due to water contamination. The Stockert system is commonly used in medical practice. The machine supplies temperature controlled water to external heat exchangers or warming/cooling blankets on patients who are undergoing cardiothoracic surgery. They aid in circulating the blood and keeping organs at the temperature best suited to the type of surgery being performed. The water is provided to the blankets through closed circuits, and therefore has no physical contact with patients. However, the contaminated water is released through the exhaust vent of the machine, causing the bacteria to be transmitted to the patient.
In April 2016, a European study was published that detected a link between M. chimaera clinical samples from several infected cardiothoracic patients, samples from the heater-cooler devices used during said patient’s procedures, and environmental samples from the manufacturer’s facility. The contamination is believed to have occurred during the manufacturing of the product, specifically in models assembled prior to September 2014.
Mycobacterium Chimaera Spread by 3T Heater-Cooler Devices
Mycobacterium chimaera is responsible for the NTM infections that have occurred in patients who have come into contact with the Stockert Heater-Cooler system during cardiac surgery. While NTM infections caused by the 3T heater-cooler are rare, M. chimaera can cause serious illness or even death. The bacteria is not transmitted easily, however those with weakened immune systems are particularly susceptible to infection. Furthermore, the infection may not present symptoms for months, or even years, making it difficult to detect in patients. The symptoms of NTM infections include night sweats, muscle aches, weight loss, fatigue, and unexplained fever.
Safety Communication Issued by FDA over Heater-Cooler Infection Concerns
In October of 2015, the FDA issued a safety communication regarding the link between NTM infections and heater-cooler devices. The statement discussed the contamination of the device and aimed to provide recommendations to minimize the risk of infections in patients. The FDA then issued a Warning Letter to LivaNova PLC for its Stӧckert 3T Heater-Cooler System. This was a result of issues with the device that were discovered upon inspections conducted at facilities in Munchen, Germany and Arvada, Colorado. Due to the risks posed by these violations, the 3T devices manufactured in Munchen were placed under import alert. This restricted the availability of the 3T devices to facilities where the device is medically necessary. Since issuing the statement, the FDA has continually worked to investigate risk factors and causes of transmissions of bacteria through heater-cooler devices. As new information surfaces, the FDA will continue to update safety recommendations for patients and healthcare facilities.
The Center for Disease Control issued a letter for open-chest cardiac surgery patients to bring to their healthcare providers. The letter explained the details of the infection these patients had been exposed to from use of the heater-cooler device. It listed the symptoms of NTM infections and alerted health care providers to be aware of potential risks. They also outlined a course of action if a patient is suspected of having an NTM infection. The CDC recommends obtaining an acid fast bacilli (AFB) culture to identify the organism. This will determine whether M. chimera is present. The letter concluded stating that healthcare providers should contact the CDC with any questions regarding the infection.