The Food and Drug Administration (FDA) has issued a safety communication, warning that the automatic clutch mechanism in some cranial perforators—devices to drill into the skull—may fail to disengage and automatically stop drilling after the skull is penetrated, injuring the patient.
Most cranial perforators are designed to automatically stop drilling in order to prevent the tip from unintentionally drilling or “plunging” into the brain. But the clutch mechanism may fail to disengage if the device selection and proper use are not in accordance with the manufacturer’s instructions and the patient can be injured, the FDA warns.
Cranial perforators are bone cutting and drilling medical devices used to create a small hole (burr hole) in a patient’s skull so that the neurosurgeon can access the brain during certain procedures. These devices often have a clutch mechanism that is designed to automatically disengage or stop the tip from drilling once it has penetrated the patient’s skull to prevent damage to the brain.
The FDA says the consequences of cranial perforators failing to disengage can be serious. From January 2005 through August 2015, the FDA received more than 300 medical device reports (MDRs) associated with the failure of an automatic clutch mechanism to disengage, resulting in over 200 injuries. These reports describe injuries including perforation of the brain’s protective covering just beneath the skull (dura mater), bleeding (hemorrhage), brain contusion, cerebral tissue damage, and decreased function of the brain (neurological deficit). The outcomes from these injuries have included seizures, damage to the portion of the brain responsible for language (aphasia), prolonged hospital stays, and the need for additional procedures.
The FDA said its analysis of currently available data suggests that failure to disengage is not specific to any manufacturer or brand of device. The risk of failure to disengage can be mitigated through proper use of the device, patient considerations, and selection of the device in accordance with the manufacturer’s instructions for use. Failing to follow the manufacturer’s instructions can result in the device not performing as expected, potentially placing patients at risk.
The FDA recommends that neurosurgeons follow the device labeling instructions and select the device appropriate for the particular procedure. The FDA advises that the neurosurgeon to
- Select the appropriate cutting accessories based on the patient’s skull thickness.
- Hold the perforator perpendicular to the inner table of the skull at the point of penetration throughout the entire drilling procedure.
- Do not rock, rotate, or change the angle of the device during drilling.
- Avoid using excessive pressure when nearing the point of perforation to prevent penetration into the brain.
In addition, the FDA advises caution when perforating the skulls of infants, children, or elderly patients because of varying skull consistency and thickness of bone.
The FDA encourages prompt reporting of adverse events to help the FDA identify and better understand the risks related to the use of medical devices. Such events can be reported through the MedWatch safety information and adverse events reporting program: www.fda.gov/medwatch/report.htm.