The past few years have seen a quiet revolution in the treatment of ischemic strokes, which can cause death or disability when a blood clot blocks an artery in the brain.
For years, the usual therapy has been a timely dose of a clot-dissolving drug called tPA. It must be adminstered within 4 1/2 hours of the onset of symptoms, however, and only benefits a small percentage of patients.
The new gold standard, endorsed last year by the American Heart Association and others, involves using a catheter device to mechanically extract clots. The procedure rapidly restores blood flow and leads to dramatically better outcomes.
UNM Hospital’s neuro-critical care team is the only group in the state equipped to provide this care. And because it expands the window for treatment to six hours or more, patients from throughout New Mexico can be airlifted to UNM in time to benefit.
“This is top-level care, anywhere in the world,” says Howard Yonas, MD, chair of UNM’s Department of Neurosurgery. “We’re the only players in the state that have this capacity. We’re talking with all the major hospitals in the state about how they can get their patients here.”
Endovascular thrombectomy – it’s a mouthful – involves inserting a catheter through a blood vessel in the groin and carefully threading it through the circulatory system into the affected area of the brain. It requires careful choreography among paramedics, emergency room imaging specialists and interventional radiologists. UNM specialists are on call 24/7 so can treatment can start within an hour of a patient’s arrival, Yonas says.
A key element is the ACCESS cerebrovascular consult service, which electronically links emergency rooms throughout the state with UNM neurosurgeons, enabling them to review the CT scans of stroke patients and determine whether they would benefit from the procedure.
Yonas and his team have worked out an ER protocol to ensure that stroke patients are rapidly evaluated for treatment. “When you hit the door, we press the stroke button,” he says. “You will be in the CT scanner within 10 minutes. We will will make the determination of whether you have a blocked artery, whether you should get tPA, or whether you’re suitable for thrombectomy.”
This method helps 30 to 40 percent of patients, instead of the 8 to 10 who benefit from tPA alone, Yonas says. “It’s a giant leap in improvement.” The new endovascular service is also a key part of the push to get UNMH certified as a comprehensive stroke center, he adds.
Robert Alunday, MD, an assistant professor of neurosurgery and emergency medicine, says ambulance crews are expected to radio ahead to the ER when transporting a patient they suspect is having a stroke. A team of doctors meets the patient at the door and within a few minutes they are evaluating the CT scan, he says.
The scan reveals whether the patient is having an ischemic stroke caused by a blocked artery or a hemorrhagic stroke from a vessel bleeding into the brain. It can also help doctors determine whether the patient would benefit from tPA with or without the endovascular procedure.
Alunday has seen dramatic results in patients who arrive at the hospital paralyzed and unable to speak. “You can make them go to having conversations with you and moving their arms again,” he says.
Alunday’s colleague Huy Tran, MD, an assistant professor of neurology and neurosurgery, says thrombectomy is especially helpful in removing clots from large blood vessels – which typically cause the worst outcomes. Patients who otherwise might have been permanently disabled often are able to regain use of their limbs, he says.
“More people are able to achieve functional independence with the devices when they have large vessel occlusions,” he says.