Medtronic and Monteris Medical are suggesting procedural techniques to reduce unintended thermal damage linked to their magnetic resonance-guided laser interstitial thermal therapy devices, the US Food and Drug Administration (FDA) said Thursday.
The agency summarized the new information from both medical device manufacturers and provided updated recommendations in two letters to health care providers. Medtronic issued three advisory letters between June and August to provide mitigation strategies as supplements to its June Class II recall, whereas Monteris Medical obtained FDA clearance for a new device.
The actions are intended to encourage the safe use of magnetic resonance (MR) thermometry by helping to inform patient management decisions and mitigate the potential risk of patient injury.
FDA granted 510(k) clearance on Monteris Medical’s premarket submission for its redesigned NeuroBlate System that includes updated labeling on MR thermometry use to aid in predicting thermal damage. The new NeuroBlate probe, with a fiber optic temperature sensor, “replaces the metallic thermocouple temperature sensor of the original design,” the agency noted.
The safety risks associated with the use of the recalled sensor remain so “health care providers should consider on an individual basis, the benefits and risks of the probe with the metallic thermocouple, as well as the availability of alternative treatment modalities” until the new probe is made available, FDA cautioned, pointing to Monteris Medical to get the launch timeline.
For use of both magnetic resonance-guided laser interstitial thermal therapy device types, the agency is recommending that health care providers “keep the cooling system running throughout thermal monitoring, including when the laser is on and after it is shut off, to bring the tissue next to the fiber back to baseline temperature within 120 second post laser delivery.”
The new letters follow up on the preliminary information FDA used to inform of a Class I recall and issue a safety alert in March and April, respectively. The recall was initiated over “several instances of unintended heating and damage to the Monteris Medical NeuroBlate probe, which may have resulted in unintended damage to surrounding brain tissue.” The safety alert relates to the risk of tissue overheating due to inaccurate magnetic resonance thermometry information.
FDA previously reported reviewing several medical device reports (MDR) and literature reports describing events that may have been associated with patient deaths. These include an MDR of a patient “who experienced an intracranial hemorrhage and died, although causality with the device malfunction cannot be concluded with certainty.” Other adverse events linked to use of the devices, including neurological deficits and intracranial bleeding, among others, have also been observed when the devices were used for treating intracranial lesions, according to FDA.
Update Regarding Unintended Heating Associated with the Monteris Medical NeuroBlate Probe
Update Regarding Risk of Tissue Overheating Due to Inaccurate Magnetic Resonance Thermometry