LivaNova (NSDQ:LIVN) this week updated customers on efforts to correct issues with its 3T Heater-Cooler related to patient infections, providing instructions to monitor hydrogen peroxide concentration and information on a design upgrade.
In a medical device correction letter dated October 18, the company sent instructions for monitoring hydrogen peroxide concentration to limit microbial growth, enhancing previous instructions, and informing users of a new vacuum canister and internal sealing design intended to “further mitigate” the risk of airborne transmission on non-tuberculosis mycobacterium.
Last September, a report emerged suggesting that approximately 12 children who underwent cardiac procedures at Children’s Hospital New Orleans earlier in the year were infected with myobacterium previously linked to the 3T systems.
LivaNova said that initial 3T operating instructions laid out disinfection procedures which aimed to keep a total heterotrophic plate count of less than 100 CFU/ml within the water circuit of the device, which does not come into direct contact with the patient. The company said that if hydrogen peroxide concentration in the water circuit drops below 100 ppm, microorganisms could start to grow between bi-weekly disinfection cycles.
The company warned that even though the fluid in the water circuit does not come into contact with patients, users should be “mindful that aerosols are emitted with the 3T is used, primarily during the patient warming phase at the end of a procedure, when water is returned to the tanks.”
LivaNova said that patients could also come into direct contact with water and solution droplets containing water-borne microorganisms, which could lead to cardiovascular infections including endocarditis or other deep-surgical-site infections.
The company said that it observed a decrease of hydrogen peroxide concentration to zero within a day in a “limited number of devices tested after a period of clinical use.” In the devices, LivaNova said it observed a degradation of nickel coating on cooling coils in the tanks which resulted in exposed copper.
LivaNova said it believes that the rapid hydrogen peroxide decrease could be caused by a reaction between the exposed copper and hydrogen peroxide.
Not all devices demonstrated a decrease of hydrogen peroxide below 100 ppm, LivaNova wrote, and the decrease is expected to vary by device dependent upon age, maintenance, local water conditions and other factors.
In its updated instructions, the company said that users should monitor hydrogen peroxide concentration in the water solution on a daily basis, and that a drop in the concentration over a week-long period is expected, but that the concentration should be maintained at above 100 ppm.
The company also said it developed a new vacuum canister and internal sealing design to reduce airborne transmission risk from 3T devices. It added that it will provide instructions for use when the systems are upgraded, and that users would be contacted by a company agent for the upgrade.
The issues and updates affect 120V, 127V, 200V, 208V, 230V and 240V devices with product code 16-02-80, 16-02-81, 16-02-82, 16-02-83, 16-02-85 and 16-02-95 and a number of different serial number ranges.