Federal regulators are urging neurosurgeons to exercise extreme caution when using a Minnesota-made brain probe to kill cancer cells, following reported problems that included a patient death potentially linked to the device.
The Food and Drug Administration on Thursday issued a Class I recall alert on about 50 NeuroBlate systems for MRI-guided brain surgery made by Plymouth-based Monteris Medical.
Class I recalls, the highest severity level, involve product problems that can cause death or serious injury. Because the action is classified by the FDA as a voluntary recall, there are no plans to remove the products from the field.
The FDA also issued a "Dear Health Care Provider" letter Thursday saying the agency was concerned that three product advisories Monteris issued about the problems late last year didn't sufficiently mitigate the risks.
"We are working with the manufacturer to address these concerns," the FDA letter said. "Until appropriate mitigation strategies have been identified by the manufacturer and evaluated by the FDA, health care providers should strongly consider treating patients using alternative procedures if possible."
Monteris CEO Marty Emerson said in an e-mail Thursday that the company is planning additional simulated-use testing to understand the potential risks. Monteris anticipates submitting a product for 510(k) clearance this summer that will permanently eliminate the risks, he said.
The risk is that a minimally invasive probe that can be used to burn away irregularly shaped lesions deep in the brain, called the NeuroBlate Laser Delivery Probe, can be damaged by overheating during use with the magnetic resonance imaging (MRI) system used to visualize the location of the probe. The damaged probe can then lead to unintended tissue damage, the FDA said.
"The damage to the probe appears to have been caused by an interaction between the thermocouple in the probe and the MRI environment," the FDA alert said. "These events occurred independent of laser energy delivery, and have been associated with damage to the tip of the probe implanted within the brain (e.g., charring, release of carbon dioxide.)"
Emerson said there have been 12 medical procedures reported in the FDA's Manufacturer and User Facility Device Experience reporting system related to unintended probe heating, including two cases of patient harm potentially linked to the problem.
One patient died from an intracranial hemorrhage following use of an overheated probe, but Emerson said it is not medically possible to confirm that the heating contributed to the death.
The second patient showed "limited thermal damage" to the tissue near the probe, but the damage was within the zone that was targeted for ablation anyway, and there was "no incremental tissue damage outside the targeted ablation zone," Emerson said.
He said that to date, the device has been used in nearly 1,800 procedures.
Joe Carlson • 612-673-4779
