The U.S. Food and Drug Administration (FDA) has issued a series of safety warnings concerning the potential for contaminated heater-cooler devices to cause Mycobacterium chimaera (M. chimaera) infections.

M. chimaera is commonly encountered by people in water and soil, and in that context is relatively benign. But when introduced to a surgical patient’s open chest cavity via a contaminated heater-cooler, it can become a slow-growing infectious time bomb.

What is a Heater-Cooler Device?

A heater-cooler device is used in up to 500,000 cardiac bypass surgeries as well as other related heart and lung procedures that involve surgically opening the human chest cavity.

It has tanks that hold temperature-controlled water that circulates through exchangers where the patient’s blood passes by. It is a crucial piece of medical machinery that aids in maintaining the body’s temperature throughout the duration of these very invasive surgical interventions. Generally, the benefits far outweigh the risks associated with its use.

Nevertheless, despite the fact that the water tanks are closed, a contaminated heater-cooler device can spread M. chimaera through a process of aerosolization out the machine’s exhaust vent and into the air of the operating room.

Spewing bacteria into the sterile field of the operating room and into the open wound of an unsuspecting patient, a contaminated heater-cooler device may set that person up for a localized or systemic infection that might not show up for up to four years after the surgery, eluding diagnosis.

The Sorin 3T Contaminated Heater-Cooler Device

LivaNova PLC-formerly known as the Sorin Group Deutschland—was found to have M. chimaera present in a Munich manufacturing plant where the Sorin 3T heater-cooler was made in September 2014. The FDA’s response to this finding was to issue a warning and publicly indicate that they intended to monitor the situation.

The location was retested in July 2015 and found to be clear of the offending bacterium. An updated press release was made regarding this process in June 2016. The FDA released guidelines for practitioners addressing proper maintenance for a 3T heater-cooler, depending on whether the device was manufactured before or after September 2014.

The History of Post-Surgical Infections Related to Contaminated Heater-Cooler Devices

Strange post-surgical heart infections started showing up as early as 2011. The infections were localized to three states—Michigan, Pennsylvania, and Iowa. Twenty-eight M. chimaera cases have been definitively identified by the Centers for Disease Control (CDC) from those regions. Of those 28 victims, 12 people died by the hand of the infection or its complications.

While no cases of infection have been reported from Sorin 3T heater-cooler devices manufactured after September 2014, the situation shed light on the necessity of putting these machines through strict cleaning protocols that had not been instituted prior to the crisis.

In June of this year, the FDA amplified updated warnings, instructions, and machine deep-cleaning services provided by the LivaNova Co.

What are the Symptoms of M. Chimaera Infection?

If you or a loved one have had any open chest procedure within the last four to five years and have experienced flu-like symptoms such as fatigue, weakness, unexplained fever, and muscle or joint pain, care of a physician should be sought immediately. Because M. chimaera infection is so slow growing, diagnosis might be elusive and specific testing might need to be requested.