Stockert 3T System “No Easy Fix” and the FDA’s Catch-22

Washington, DCReports from both the US and Germany have identified the M chimaera contamination of  heater/cooler devices, of which 60 to 70 percent stem from the Stockert 3T heater-cooler system. But controlling the infection is challenging—to say the least.

A field investigation by the Pennsylvania Department of Health and the
CDC performed whole genome sequencing on cardiac patients in US hospitals and their findings are in line with the results of an outbreak investigation in Germany, April 2015 to February 2016, reported by Haller S, Höller C, Jacobshagen A, et al.

A commentary by The Society for Healthcare Epidemiology of America (SHEA) in collaboration with Medscape (December 22) “strongly suggests” a point-source contamination of LivaNova 3T HCDs with M chimaera. But identifying the source is one thing; finding a solution another. The Stockert 3T is not easy to replace, and there are many in use. And removing the heater-cooler devices from the operating room could put lives at risk. “Building solutions… are one possibility, but there are several pitfalls,” said Rami Sommerstein, MD. He explained that one possible solution may increase temperature and threaten the surgical outcome. Another, to build an airtight stainless steel housing for the Stockert 3T, will take a long time and to achieve air-tightness (air can also be contaminated) construction is complex.

Cleaning the Stockert 3T does not eradicate the persistent M chimaera. At the Stockert 3T manufacturing site (LivaNova HCD in Germany) Haller and colleagues applied to the devices an intensified cleaning and disinfection protocol. But the Mycobacterium re-emerged “This study demonstrated that M chimaera colonization may be ineradicable from LivaNova 3T HCDs,” said Dr. Sommerstein.

Although thousands of patients in the United States have been notified regarding potential exposure to the contaminated Stockert 3T and similar devices, the CDC believes many more people may not be aware of exposure—and they may be at risk. More than 250,000 000 procedures using cardiopulmonary bypass are performed in the United States each year, according to the CDC, which estimates the Stockert 3T represents 60 percent of the US market (LivaNova estimates 70 percent).

FDA’s Catch-22
Meanwhile, the FDA updated its safety warning. It is “continuing to gather information, issue communications, and assess the situation from both public health and regulatory perspectives” and recommends that facilities “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.”

At the same time, the agency also says:

“Be aware that heater-cooler devices are important in patient care. In appropriately selected patients, the benefits of temperature control during open chest cardiothoracic procedures generally outweigh the risk of infection transmission associated with the use of these devices.

And talk about a Catch-22: The agency warns not to have the heater-cooler devices tested due to “technical challenges related to sample collection, the long culture time, and the high rate of false negative tests. Therefore, [testing] is not recommended at this time.”

This warning leaves healthcare professionals in a quandary. Do they do nothing and wait until contamination is possibly found, or do they remove the Stockert device and risk a problem with temperature control during surgery? Or should the patient be made aware of this issue and decide?