For years, doctors have searched for effective emergency treatment of ischemic strokes, which are caused by blood clots that block an artery to the brain. In 2015, research found that a sophisticated new therapy, mechanical thrombectomy, can greatly improve the chances of recovery for certain stroke patients. We have been excited to provide this effective treatment as part of UT Southwestern’s Advanced Comprehensive Stroke Center. However, until now, we believed that it could be given safely only within 6 hours of the known onset of stroke symptoms.
This timeline posed distinct barriers to care. Many patients can’t get to a comprehensive stroke center within six hours of symptom onset. For instance, a patient’s stroke symptoms might go unrecognized, or the patient might suffer a stroke during sleep and wake up unable to pinpoint the time that symptoms began.
The foundations of this standard were shaken Jan. 24, 2018, at the International Stroke Conference in Los Angeles. Researchers presented results from the DAWN and DEFUSE 3 trials, which indicate that thrombectomy can be effective in certain patients up to 24 hours after stroke symptom presentation. In these patients, thrombectomy can double a patient’s chances of avoiding disability after stroke.
Dramatic improvements are imminent in stroke care
The adage “time lost is brain lost” has been forged in the minds of stroke doctors for years. While rapid treatment unequivocally yields the best results, the new data suggest that a larger population of people who couldn’t receive these treatments before can now get them without sacrificing effectiveness.
While swift treatment still is critical, we can now extend the timeline of potential treatments:
- Up to 4.5 hours after stroke symptoms: The patient can receive clot-busting tissue plasminogen activator (tPA) to dissolve the clot and improve blood flow to the brain. After 4.5 hours, tPA is ineffective and potentially dangerous to the patient. Until 2015, this was the only known effective treatment to reduce brain damage after a stroke.
- Up to 6 hours after stroke symptoms: In 2015, thrombectomy was proven effective for clot removal. In patients found to have clots in specific locations, we use brain imaging and a catheter procedure to snatch, collect, and remove an obstructive clot.
- 6 to 24 hours after stroke symptoms: Patients can now be evaluated to determine possible eligibility for thrombectomy. Using advanced CAT scans or magnetic resonance imaging (MRI) doctors can find the location of the clot, determine whether the patient can still qualify for clot removal, and arrange transfer to a Comprehensive Stroke Center to perform the procedure.
Eligibility for thrombectomy after stroke
In general, patients who arrive at UT Southwestern’s Advanced Comprehensive Stroke Center can receive thrombectomy if they meet the following criteria:
- Their stroke is ischemic
- The blood clot is located in or close to the neck in a large artery we can access with our instruments
- Their brain damage is ongoing, not ceased
If a patient arrives with a clot that is far from the neck or in an artery that is too small to access, thrombectomy is not a safe option. Similarly, if the stroke’s wave of damage on the brain has completed, thrombectomy will not help and might cause further risk.
Translating the research to our patients
UT Southwestern utilizes a complex, collaborative stroke care system that starts before a patient enters our doors. Emergency medical responders throughout Texas understand the impetus to deliver the patient directly to the nearest comprehensive stroke center, not the closest local emergency department.
We are the first Comprehensive Stroke Center in North Texas to be certified by The Joint Commission and the AHA. As such, we see a substantial volume of ischemic stroke patients each year, many of whom arrive in critical condition after transport from another facility. Our patients have access to the largest stroke team in the region, with 24/7 staffing of neurosurgeons, neurologists, radiologists, hospitalists, and other providers to triage even the most complex stroke patients to advanced care.
Though our treatment window is now substantially longer for more patients, it is still just as critical that patients and families act quickly when stroke symptoms are recognized. We stress that patients or families call 911 the moment a stroke is suspected to access advanced care fast.
If you’re concerned about a loved one’s stroke risk, request an appointment with your primary care doctor or call 214-645-8300 today.
