Coatings are applied to medical devices used in minimally invasive procedures to improve lubricity. Polytetrafluoroethylene (PTFE), polyvinylpyrrolidone (PVP) and silicone, among other materials, improve device maneuverability for the surgeon and minimize patient trauma and the formation of blood clots. Unfortunately, the materials also may detach from the substrate, causing serious injury and, in a handful of cases, death. This week, FDA issued a safety communication related to these coatings to make healthcare providers aware of the risks and suggest prevention techniques.
Hydrophilic and/or hydrophobic coated devices have been used for more than 20 years, notes the agency in its communication. The coatings reduce friction between blood vessels and devices such as intravascular and balloon angioplasty catheters, guidewires, delivery sheaths and implant delivery systems.
Although millions of patients have benefitted from this technology, FDA reports that it has received information concerning serious adverse events associated with coatings separating from intravascular medical devices, resulting in 11 recalls from various manufacturers since January 1, 2010. Most of the recalls were associated with guidewires, the agency notes, but other types of devices, including sheaths, retrieval devices and embolization device delivery wires used in the vasculature, have also been implicated.
In addition, since Jan. 1, 2014, FDA has received approximately 500 Medical Device Reports (MDRs) describing separation of hydrophilic and/or hydrophobic coatings on medical devices. Again, most of the MDRs involved guidewires. In addition to the MDRs, FDA has researched medical literature and physician surveys to determine occurrence rates, as MDRs are not considered definitive evidence of a defective device.
Of the 11 MDRs that described patient deaths, nine reports were also described in the published literature. In these cases, "occlusion of blood vessels reportedly occurred due to embolization of coating particles from devices during heart and brain catheterization procedures contributing to clinical adverse events such as heart attack and bleeding inside the brain," notes the agency. No specific manufacturer or device brand is associated with higher risks than others, stresses the safety communication, adding that there may be multiple contributing factors to coating separation including device design, device manufacturing, and use.
Regarding the latter, FDA recommends that healthcare providers follow a number of steps to prevent the coating from flaking or peeling off the device. Among other recommendations, the agency advises practitioners to take into account the intended use of the device, to follow proper storage procedures, ensure that there is a good fit when two devices are used together and, if applicable, adhere to the manufacturer's preconditioning process to activate the lubricious properties of the coating.
FDA is not discouraging the use of devices with these coatings. "Based on current understanding of the benefits and risks of devices with these coatings, the FDA believes that the overall benefits of these devices continue to outweigh the risks," notes the safety communication.
Read the full safety communication on the FDA website.