Deadly Infections Linked to Heart Surgery Device

Critics see holes in FDA monitoring

The FDA was aware of infections linked to a heart-surgery device by the summer of 2014, but waited 14 months before issuing a public alert, according to an article posted on the Kaiser Health News website. And it wasn’t until last month—more than two years later—that the agency issued recommendations to hospitals and patients on what to do. Critics say a swifter response could have saved thousands of patients from being exposed to potentially deadly bacteria.

Hospitals, which consider the heater-cooler machines crucial in open-heart surgery, are scrambling for ways to protect patients. And authorities have urged hospitals from New Jersey to California to notify hundreds of people who underwent surgery in recent years that they might be harboring a dangerous infection. Patients have sued, claiming they were infected in Pennsylvania, Iowa, South Carolina, and Quebec, Canada.

Experts and patient advocates say these cases are only the latest to expose holes in the FDA’s approach to spotting and responding to dangerous deficiencies in medical devices, according to the Kaiser article.

“It’s another example of the poor oversight of medical devices and how the industry has accepted infection as the cost of doing business,” said Helen Haskell, founder of the patient advocacy group Mothers Against Medical Error in Columbia, South Carolina.

Approximately 60% of U.S. hospitals that do heart surgeries rely on the Sorin 3T heater-cooler device, which was approved for sale in 2006. But five other manufacturers sell heater-coolers in the U.S., and FDA officials say that these machines share similar design features that make them prone to contamination.

The devices circulate water to warm or cool patients during bypass surgery, valve replacements, and some transplants. More than 250,000 heart bypass operations using heater-cooler devices are performed annually in the U.S.

The infections caused by these devices can be slow-growing and often don’t trigger symptoms for months or even years, making them difficult to track. As a result, the risk is hard to quantify. At least 79 cases of infection tied to Sorin heater-cooler units in the U.S. and worldwide have been reported to the FDA since 2010, including 12 deaths. Those numbers are expected to rise, the Kaiser article notes.

The potential for contamination of heater-coolers was raised as early as 2002. In a published study, doctors at a German hospital found that “germs and particles pollute” the units and that disinfecting them is very difficult.

The study, presented at a medical conference in New Orleans, said the makers of the devices often “do not provide any technology to reduce bacterial or other contamination,” posing potentially serious consequences for patients.

The study focused primarily on water spilling out of the unit and contaminating the operating room. But it also raised the prospect of waterborne pathogens causing infection through “aerosolization”—which is believed to be the way the recent infections in the U.S. and Canada occurred. The units examined were not Sorin devices.

The FDA visited Sorin’s Munich, Germany, plant in April 2011 to address safety concerns about the heater-cooler machine, according to a lawsuit filed this month. That suit says Sorin’s instructions for disinfecting the heater-cooler every two weeks allowed “bacterial overgrowth well in excess of safe standards” in just a day and a half.

The water in the devices doesn’t come into direct contact with patients, so there wasn’t much concern about infection until recently, health officials said. But it turns out lethal bacteria can grow inside the machine and become aerosolized through the unit’s exhaust fan. The germs can float down into the patient’s open chest or stick to an implantable heart valve.

Many—but not all—of the confirmed infections involved Mycobacterium chimaera, a species commonly found in soil and tap water. These organisms generally aren’t harmful to healthy people, but officials said they can lead to serious infections in patients who are already ill or have weakened immune systems.

The FDA has stated that heater-coolers “remain critical to patient care” and can’t be removed without a viable alternative. That has put many hospitals in a quandary. Some hospitals, such as the University of Iowa, chose to cut holes in the operating room walls, moving the units next door so the fan exhaust isn’t falling on patients and surgical instruments. Other hospitals have put enclosures around the machines or pointed the exhaust fan away from patients and the surgical field. Many are now using sterile or filtered water in their machines, as health officials have recommended.

Source: Kaiser Health News; November 29, 2016.