The Stockert 3T heater-cooler system, a device used to regulate body temperature during certain surgeries, has been linked to a dangerous microorganism. Mycobacterium chimaera can cause infections that carry a roughly 50 percent mortality rate.
The Stockert 3T heater-cooler system is used to regulate a patient’s body temperature during cardioplegic surgeries that stop the heart and blood flow. Certain cardiothoracic surgeries involving the heart and lungs, such as a transplant, require cardioplegia to be successful.
The Stockert 3T uses a closed-water circuit to regulate the temperature of bypass machines, oxygenators, heating or cooling blankets and other equipment that keep the patient’s body at an optimal temperature for such operations. The 3T model has three separate water tanks to accomplish this. Temperature can be adjusted to the tenth decimal point. When the procedure is done, the system also has a water pull-back feature to make cleanup easier.
The Sorin group originally developed the Stockert 3T, so sometimes the model is also called the Sorin 3T. Today, LivaNova owns the product. Sorin merged with another European medical device company to become LivaNova in 2015.
In 2015, the U.S. Food and Drug Administration issued a warning letter about the Sorin 3T, linking it to nontuberculous mycobacterial (NTM) infections. The Centers for Disease Control and Prevention issued a similar warning. Then, in October 2016, both the CDC and FDA issued a stronger warning for patients and hospitals. More than 250,000 heart bypass procedures and about 60 percent of these procedures use the Sorin Stockert 3T, the device associated with serious NTM infections. According to the CDC, the risk of contracting an infection is “between about 1 in 100 and 1 in 1,000.”
Side Effects and Complications
Testing has shown the Stockert 3T is linked to mycobacteria because of its water tanks. Mycobacteria grow in water, and it is possible for the bacteria to grow in the water used in the heater-cooler system. Although this water never touches the patient, researchers found it’s possible for the water inside the Sorin 3T to turn into a gas and enter the operating room. If the water was contaminated, the bacteria is spread through the air into the sterile field, including onto sterile equipment, into the patient’s body cavity and onto any implants.
According to the CDC, there is a 1 percent risk patients who had a cardioplegic surgery involving a Sorin 3T will contract M. chimaera. If they do develop the infection, the bacterium is particularly slow growing and will take several months, if not years, to show symptoms. Typically the first sign of M. chimaera is an unexplained fever. If a person had cardiothoracic surgery or a transplant within the past four years and develops such a fever, they could have the rare infection.
Symptoms of M. chimaera are:
- Fever lasting more than one week
- Loss of energy
- Night sweats
- Joint or muscle pain
- Redness, heat or pus around a surgical incision
- In infants, a failure to grow or gain weight
- Difficulty breathing
- Persistent cough or cough with blood
M. chimaera is fatal to roughly half of the people who contract the infection. Of the 32 cases of M. chimaera the FDA was aware of between 2010 – 2015, nearly half of the patients died. These outbreaks — eight cases in the U.S. mostly from a hospital in York, Pennsylvania, and 24 cases in Europe linked to hospitals in Switzerland, the Netherlands and Germany — all involved patients who had surgeries using the Sorin 3T.
Stocker 3T Infection and Treatment
M. chimaera and other nontuberculous mycobacteria are considered to be rare infections because they mostly come from environmental sources, such as soil or water. Most people exposed to the organisms typically do not experience a negative effect. An immunosuppressed person is most likely to contract the infection, therefore making people with chronic diseases or health conditions the most vulnerable.
Doctors may find diagnosing M. chimaera challenging because the infection has such a long incubation period before symptoms show, and because it’s not likely to affect the average person. Medical professionals typically diagnose M. chimaera using a mycobacterium blood culture. Although a fairly common tool, most doctors do not typically screen patient blood samples for mycobacteria unless the person is immunosuppressed.
The infection is difficult to treat, contributing to its nearly 50 percent mortality rate. Treatment options often involve multiple prescriptions for maximum-strength antibiotics, which have other adverse effects on the patient. In many cases, treatment also calls for a second surgery to remove an implant that may have become contaminated with the bacteria during the original surgery involving the Sorin 3T.
According to a 2011 study of patients facing nontuberculous mycobacterial infections, the average treatment course was 14 months and cost an average of $4,916. The median monthly cost for all patients was $321, but varied more or less depending on whether the patient was receiving oral or intravenous medication.
FDA and Manufacturer Recall
The Sorin Group initiated a Stockert 3T recall on June 15, 2015, and the FDA announced Sorin’s recall of the Stockert 3T on July 15, 2015. The recall stated the Stockert 3T had “potential colonization of organisms, including Mycobacteria.”
The specific mycobacteria linked to the Stockert 3T is M. chimaera. Between 2010 and 2015, the FDA was alerted to 32 cases of M. chimaera globally. On Oct. 15, 2015, it released a safety communication advising of the public-safety risk mycobacteria may cause, and provided recommendations to limit the public’s exposure. The CDC issued a similar safety notice later that month.
On Dec. 29, 2015, the FDA issued a warning letter to Sorin for the Stockert 3T. According to the letter, an inspection of the company’s production facilities in Germany and Colorado revealed violations to safety protocol. On June 1, 2016, the agency released a second safety communication about Mycobacteria chimaera, linking the bacteria’s spread to the Stockert 3T.
According to its second communique, it’s possible all 3T models manufactured before September 2014 may have been contaminated with M. chimaera. The FDA recommends hospitals with these machines establish a comprehensive follow-up system for the patients who may have been exposed.
Many of those affected by the contaminated Sorin 3T heater-cooler system have begun to seek justice for their pain and suffering in court. As recently as June 2016, two families filed suits against LivaNova, the manufacturer of the Stockert 3T, and WellSpan Health, the owner of York Hospital, where both patients were treated.
In one personal injury suit, the plaintiff argues both the hospital system and the device manufacturer directly caused his avoidable chronic illness, pain and suffering and loss of earning following an open-heart surgery involving the 3T model that led to a mycobacterial infection. The second suit is a wrongful-death claim on behalf of David Inners, a 62-year-old man who died almost one year after a surgery involving a Stocker 3T that exposed him to a mycobacterial infection. The suit accuses LivaNova of faulty device design and WellSpan Health of recklessness and negligence.
As increasingly more hospitals inform their patients they were possibly exposed to the bacteria, more cases are expected to be filed. Settlements are expected to vary from hundreds of thousands to millions in reparations.