Cardiac specialists undertook 500,000 heart bypass surgeries in a recent earmark year in the U.S, according to the Texas Heart Institute. A heater cooler device is a common and necessary piece of equipment used in the operating theater for this type of surgery, but a certain brand has been counted among heart surgery infection causes.

While being very rare, heart surgery infection causes were reported to be linked to heater cooler devices in general at first. In a safety communication released by the U.S. Food and Drug Administration (FDA) in October 2015, the connection was made because of 32 medical device reports presented to the drug and medical device oversight agency.

While no specific brand of heater cooler device was named as the culprit at the time, subsequent investigations discovered that the Stockert 3T Heater Cooler System—also known as the Sorin 3T Heater Cooler System—could have been among likely heart surgery infection causes.

LivaNova PLC, which had been formerly known as the Sorin Group Deutschland, was found to have a Germany-based manufacturing facility contaminated with Mycobacterium chimaera in September 2014.

Eight months after the initial warning in which the FDA claimed they would monitor the situation, a follow-up report naming the Stockert 3T heater cooler device among possible heart surgery infection causes was released. This report came out in the early summer of 2016.

When the Germany-based manufacturing facility was retested in July 2015, all evidence of M. chimaera had been eradicated. Stockert 3T Heater Cooler Systems manufactured after the initial contamination finding date have not been named among heart surgery infection causes.

Nevertheless, the danger has not passed for the thousands of patients that have undergone open heart surgery using older machines.

The Danger of M. Chimaera Infection Has Not Passed

M. chimaera is a bacteria routinely encountered in our air and soil. It is, for the most part, benign to humans unless we are laying open-chested in an operating theater. In this situation, encountering the nontuberculous mycobacterium can be a serious danger, but one that might not be evident for some time.

The heart surgery infection related to this exposure is slow-growing and may be asymptomatic for upwards of four years after bypass intervention. When they do reveal themselves, these symptoms may be easily mistaken for the flu in that there are night sweats, unusual fevers, generalized weakness and muscle and joint pain.

Former cardiac bypass patients with current or recurrent problems that closely resemble or mirror these symptoms should seek the care of their physician.

Starting in 2011, heart surgery infection cases started appearing in the states of Iowa, Michigan and Pennsylvania. While only 28 patients have been identified by the U.S. Center for Disease Control (CDC) as having the M. chimaera infection beyond a shadow of a doubt, the FDA has indicated that 12 of those people have succumbed under the strain of fighting the mycobacterium.

How the Stockert 3T Heater Cooler System Allegedly Broke the Sterile Field

Heater Cooler Devices have a water tank that contains temperature-controlled water. The patient’s blood circulates in close proximity but does not come in contact with the tank. The contaminated devices were believed to aerolize the specific bacterium through the machine’s venting system, breaking the sterile field of the operating room.

Sixty percent of Stockert Heater Cooler Systems manufactured before the plant was found to be cleared of contamination are still in use across the country, although medical personnel are better trained on how to manage the machines to prevent future problems.