Clot Retrieval Treatment Window Expanded for Stroke Patients

On February 15, 2018, the FDA cleared the use of the Trevo clot retrieval device to treat certain stroke patients up to 24 hours after symptom onset, expanding the device’s treatment window by 18 hours. This device is cleared for use as an initial therapy for strokes due to blood clots (also known as an acute ischemic stroke) to reduce paralysis, speech difficulties, and other stroke disabilities, and only as an addition to treatment with a medication that dissolves blood blots called tissue plasminogen activator (t-PA). The device was previously cleared for use in patients up to six hours after symptom onset.


“Time is critical following the onset of stroke symptoms. Expanding the treatment window from six to 24 hours will significantly increase the number of stroke patients who may benefit from treatment,” said Carlos Peña, Ph.D., director of the division of neurological and physical medicine devices at the FDA’s Center for Devices and Radiological Health. “Health care providers and their patients now have better tools for treating stroke and potentially preventing long-term disability.”


A stroke is a serious medical condition that requires emergency care and can cause lasting brain damage, long-term disability, or even death. According to the CDC, stroke is the fifth leading cause of death in the U.S. and is a major cause of serious disability for adults. Approximately 795,000 people in the U.S. have a stroke each year. Ischemic strokes, strokes due to blood clots, represent approximately 87 percent of all strokes.


The Trevo device was first cleared by the FDA in 2012 to remove a blood clot and restore blood flow in stroke patients who could not receive t-PA or for those patients who did not respond to t-PA therapy. In 2016, the FDA allowed expanded marketing of the device for certain patients in addition to treatment with t-PA if used within six hours of the onset of symptoms. The expanded indication increases the amount of time that the device can be used once the symptoms are present.


Trevo is a clot removal device that is inserted through a catheter via the femoral (thigh) artery up through the blood vessel to the site of the blood clot. The device grips the clot, allowing the physician to retrieve the clot by pulling it back through the blood vessel along with the device for removal through a catheter or sheath.


The FDA evaluated data from a clinical trial comparing 107 patients treated with the Trevo device and medical management to 99 patients who had only medical management. Approximately 48 percent of patients treated with the Trevo device were functionally independent (ranging from no symptoms to slight disability) three months after their stroke compared to 13 percent of patients who were not treated with the Trevo device.


Risks associated with using the Trevo device include a failure to retrieve the blood clot, embolization (blockage) to new territories in the brain, arterial dissections (tears in blood vessels), and vascular perforations (holes poked through blood vessels), and access site complications at the femoral (thigh) artery entry point.


See the FDA Announcement


See also Medical Law Perspectives Report: Stroke: Challenges, Risks, and Liability Issues


See also Medical Law Perspectives Report: When Urgency Leads to Errors: Liability for Emergency Care


See also Medical Law Perspectives Report: The New Oral Contraceptives: Stroke and Other Adverse Event Liability