The Food and Drug Administration (FDA) recently issued a Medical Device Safety Communication update to provide new information about Mycobacterium chimaera infections associated with the use of the LivaNova/Sorin Stöckert 3T Heater-Cooler System during cardiothoracic surgery. The update includes recommendations and additional steps for health care facilities to take in order to mitigate the risk of infection associated with the use of these devices.

In its initial communication, the FDA disclosed that it received reports of invasive mycobacterial infections in patients after cardiothoracic surgery that involved the use of 3T devices. A field investigation by the Pennsylvania Department of Health, with assistance from the Centers for Disease Control and Prevention (CDC), used both epidemiologic and laboratory evidence to identify an association between the infections and exposure to contaminated Stöckert 3T heater-cooler devices.

The initial safety alert did not identify any one particular heater-cooler model or type of mycobacteria as posing the infection risk. According to a recent article in Discussions in Infection Control, such infections may not in fact be limited to the Stöckert 3T heater-cooler device or to mycobacteria chimaera. Lawrence F. Muscarella Ph.D. explains that more than one brand of heater-cooler device used during cardiothoracic surgery may be prone to contamination with potentially life-threatening bacteria.

More than 250,000 heart bypass procedures using heater-cooler devices are performed in the U.S. every year. Heater-cooler devices control the patient’s temperature by circulating heated and cooled water within a closed loop of tubes. The circulating water does not ordinarily directly contact the patient during surgery. However, a contaminated heater-cooler device may still pose a risk of infecting patients. The FDA alerts state that there is potential for contaminated water to transmit bacteria through the air and through the heater-cooler’s exhaust vent. Aerosols of bacteria released into the operating room’s air could enter a patient’s open chest, causing infection. To reduce this risk, the FDA now advises hospitals to direct the heater-cooler device’s exhaust vent away from the patient or to isolate the device in an enclosure, or remove it from the operating room altogether.

Many hospitals are contacting their patients directly to warn them of the risk of infection from exposure to contaminated heater-cooler devices. Infected patients may not develop signs or symptoms for months or even years after exposure. Thus, as many as one million U.S. patients who underwent the surgery since 2011 could be at risk of infection. Patients who have undergone cardiothoracic surgery may want to contact their healthcare providers.