Broadly implementing stroke embolectomy faces hurdles

A wide disparity existed in the rate of reperfusion use among StrokeNet hospitals. Sixty-seven hospitals, 31% of the StrokeNet group, treated at least 20 stroke patients with TPA during the study period, while 100 (47%) of the StrokeNet hospitals treated fewer than 10 acute stroke patients. The rate of those doing embolectomies was substantially lower, with 10 hospitals (5%) doing at least 20 endovascular procedures while 90% did fewer than 10.

Although Dr. Adeoye expressed confidence that the number of U.S. centers doing embolectomy cases will “change rapidly” following the new reports documenting the efficacy of the approach, he also acknowledged the challenges of growing the number of high-volume endovascular centers.

Centers that have been equivocal about embolectomy will now start doing it in a more concerted way, he predicted, but if cases get spread out and some sites do only a few patients a year, the quality of the procedures may suffer. “The more cases a site does, the better,” he noted, adding that regions that funnel all their stroke patients to a single endovascular site “do really well.”

“Right now, many hospitals want to do everything to get [fully] reimbursed and not send their patients down the line. There is a financial incentive to build up the stroke service at every hospital,” Dr. Derdeyn noted.

Another aspect to sorting out which centers start offering endovascular treatment will be the need to locate them in a rational way, as happened with trauma centers. Until now, placement of comprehensive stroke centers often depended on hospitals developing the capability as a marketing tool, noted Dr. Larry B. Goldstein, professor of neurology and director of the stroke center at Duke University in Durham, N.C. A hospital might achieve comprehensive stroke center certification, so a second center a few blocks away then follows suit seemingly to keep pace in a public-relations battle for cachet. The result has been an irrational clustering of centers with endovascular capability. He cited the situation in Cleveland, where comprehensive centers run by the Cleveland Clinic and Case Western stand a few dozen feet apart.

Challenges for triage

An analysis published last year by Dr. Adeoye and his colleagues showed that 56% of the U.S. population lived within a 60-minute drive of a hospital able to administer endovascular stroke treatment; by air, 85% had that access (Stroke 2014;45:3019-24). For TPA, 81% of people lived within a 60-minute drive of a center able to administer intravenous lytic treatment and 97% could reach these hospitals within an hour by air. While those numbers sound promising, though, fulfilling that potential depends on getting the right patients to the right hospitals.

Patient triage is perhaps the most vexing issue created by embolectomy’s success. For at least the short term, a limited number of centers will have the staffing and capacity to deliver endovascular embolectomy on a 24/7 basis to acute ischemic stroke patients who have a proximal blockage in a large cerebral artery. The relatively small number of sites able to offer embolectomy, and the much larger number of sites able to administer thrombolytic therapy with TPA, set the stage for some possible tension, or at least confusion, within communities over where an ambulance should bring an acute ischemic stroke patient.

“In some places they have trained the EMS [emergency medical services] to recognize severe strokes that are likely to benefit [from embolectomy], and they take those patients to places with endovascular capability. But there are some states with laws against doing this. There are major issues when EMS bypasses hospitals,” Dr. Derdeyn noted. “That’s the million-dollar question: How do you identify the stroke patients [with severe strokes who would benefit from embolectomy] and get them to where they need to go.” Like Dr. Adeoye, Dr. Derdeyn believes that endovascular treatment for stroke needs to be centralized at a relatively small number of high-volume centers.

“You can imagine that the fastest way to get stroke patients treated is to have them all go to one place, but that is much easier said than done,” Dr. Khatri said.

“Stent retrievers get cerebral arteries open, but that is not the biggest challenge. For the short term, the key issue is to get the correct patients to the correct hospitals where they can be treated by the correct team,” said Dr. Mayank Goyal, professor of diagnostic imaging at the University of Calgary (Alta.) and lead investigator for two of the three trials presented at the conference.

“You need a neurologist capable of deciding whether it really is a stroke, and pretty high-level imaging to identify the large-vessel occlusions that will benefit. Acquiring a CT angiography (CTA) image of the brain is a push-button process, but figuring out what the CTA says is not push button, especially the more sophisticated perfusion CT imaging to assess collateral circulation. I don’t see this capability happening in every catheterization laboratory,” Dr. Derdeyn said in an interview.