How to Reduce the Risk of Cardiac Surgery Infection When Using LivaNova Heater-Cooler System

February 27, 2020 — The U.S. Food and Drug Administration (FDA) sent a safety communication this week to healthcare to remind providers on ways to reduce the risk of cardiac surgery infection when using the LivaNova Heater-Cooler System 3T. 

Heater-cooler devices are used during cardiothoracic surgeries, as well as other medical and surgical procedures to warm or cool a patient to optimize medical care and improve patient outcomes. Heater-cooler devices include water tanks that provide temperature-controlled water to external heat exchangers or warming/cooling blankets through closed circuits. Although the water in the circuits does not come into direct contact with the patient, there is the potential for contaminated water to enter other parts of the device or transmit bacteria through the air (aerosolize) through the device's exhaust vent into the environment and to the patient.

The FDA originally sent a safety notice in October 2018, when LivaNova issued a medical device correction letter to healthcare facilities. The FDA said it continues to engage with manufacturers, healthcare facilities and the Centers for Disease Control and Prevention (CDC) in evaluating risk and mitigation measures for infections related to these systems. This is part of the FDA's ongoing evaluation and continued monitoring of reports of nontuberculous mycobacteria infections associated with heater-cooler devices.

LivaNova's medical device correction letter to healthcare facilities included the following instructions to prevent infection:

   • Provide updated instructions to monitor the concentration of hydrogen peroxide in the water circuit to verify that enough concentration of hydrogen peroxide is present to limit microbial growth and to adjust the concentration of hydrogen peroxide if it drops below 100 ppm.
   • Announce the availability of a design upgrade, called the 3T Aerosol Collection Set (vacuum canister and internal sealing), to reduce (but not eliminate) the risk of potential emission of aerosols from the 3T System.
   • In addition, the FDA cleared a new version of the LivaNova Heater-Cooler System 3T on February 25, 2020 with changes to help reduce the risk of patient infections including updated labeling (Version 21) with validated cleaning and disinfection instructions and the 3T Aerosol Collection Set.

If a facility is using a 3T system that is not the new version, healthcare providers and staff should immediately start using the updated labeling and follow recommendations in the Feb. 25, 2020 LivaNova Medical Device Correction Letter, and continue to follow recommendations in the April 20, 2018 and October 18, 2018 LivaNova Medical Device Correction letters regarding a design upgrade and deep cleaning service.

Recommendations for Healthcare Providers Using the LivaNova Heater-Cooler System 3T

The FDA said it is important to strictly adhere to the updated 3T Operating instructions (Version 21) to reduce the risk of infection. 

   • Use new accessories, tubing, and connectors to prevent contamination when using a different heater-cooler device.
   • Direct and channel the heater-cooler exhaust away from the patient, for example, to the operating room exhaust vent.
   • Be aware that device contamination may also occur from other sources such as environmental contamination or device contact with contaminated accessories.
   • Be sure to clean and disinfect any accessories connected to the heater cooler according to accessories' manufacturers' instructions for use.
   • Be aware that more frequent cleaning and using higher disinfection concentrations can damage the device.
  

If using a LivaNova Heater-Cooler  System 3T that is not the new version (i.e. has a serial number beginning with 16S):
   • Be aware of the 3T Aerosol Collection Set.
   • LivaNova has developed a vacuum canister and internal sealing design change called the 3T Aerosol Collection Set that is intended to further reduce, but does not eliminate, the risk of airborne transmission of non-tuberculosis mycobacterium (NTM) from the 3T device.
   • A LivaNova representative or local agent will contact customers to plan the upgrade of the affected products.
   • 3T devices that are at the deep cleaning facility will be upgraded while there.
   • Be aware of the availability of the deep cleaning service. The "deep-cleaning" service is available for all 3T devices less than 10 years old (the expected device lifetime).
   • If your device was manufactured prior to September 2014, you should strongly consider transitioning away from the use of these devices for open-cardiac surgery unless your device has been deep cleaned specifically by LivaNova.

If your 3T device is known or suspected to be contaminated, you should:
   • Immediately remove from service any heater-cooler devices, accessories, tubing, and connectors that have tested positive for M. chimaera or have been associated with known M. chimaera patient infections at your facility.
   • Consider contacting LivaNova for additional information about the deep-cleaning servicing of your 3T.
   • Be aware, if your device is successfully deep cleaned, following the routine cleaning and disinfection procedures found in the most recent Instructions for Use is necessary to help reduce the risk of recontamination.
   • Review the FDA's earlier recommendations provided to help reduce the risk to patients.

What is a Cardiac Heater-cooler Device?

Heater-cooler devices are commonly used to warm or cool a patient to improve medical care and patient outcomes. The LivaNova Heater-Cooler System 3T (formerly Stöckert 3T Heater-Cooler System), manufactured by LivaNova PLC (formerly Sorin Group Deutschland GmbH), is intended to provide temperature-controlled water to:
   • Oxygenator heat exchangers
   • Cardioplegia (paralysis of the heart) heat exchangers
   • Warming/cooling blankets to warm or cool a patient during cardiopulmonary bypass procedures lasting six hours or less.
   • Cardiac Surgery Infection Associated with Heater-Cooler Devices

Schematic representation of heater–cooler circuits tested for transmission of mycobacterium chimaera during cardiac surgery despite an ultraclean air ventilation system. Blue arrows indicate cold water flow, and red arrows indicate hot water flow and patient blood flow. Image from the FDA.

In appropriately selected patients, the benefits of temperature control during open chest cardiothoracic procedures (cardiac surgery) generally outweigh the risk of infection transmission associated with the use of heater-cooler devices.

All heater-cooler devices that have water tanks provide temperature-controlled water to external heat exchangers or warming/cooling blankets through closed circuits. Although the water in the circuits does not come into direct contact with the patient, there is the potential for contaminated water to enter other parts of the device and aerosolize. This could send non-tuberculosis mycobacteria (NTM) through the air and through the device's exhaust vent or other unsealed pathways, the environment, and to the patient.

Read more on the original 2018 issue with the system in the artiocle "LivaNova Warns of Potential Infection Risks With 3T Heater-Cooler Systems."