Neurointervention Groups Set Standards for Performing Endovascular Stroke Therapy

LOS ANGELES—Fifteen societies involved in neurointervention have provided criteria that physicians and hospitals must meet in order to perform endovascular ischemic stroke interventions in a consensus document released today, coinciding with the opening of the International Stroke Conference here.

The requirements would likely exclude interventional cardiologists from performing acute stroke interventions unless they have already completed specific residencies outside of cardiology, or are prepared to commit to an additional year or more of specialized training.

“We believe that a neuroscience background, dedicated neurointerventional training, and stringent peer review and quality assurance processes are critical to ensuring the best possible patient outcomes,” according to the authors. “Well-trained neurointerventionalists are a critical component of an organized and efficient team needed to deliver clinically effective mechanical thrombectomy for acute ischemic stroke patients.”

Ralph Sacco, MD, a stroke neurologist at the University of Miami (Miami, FL) and a past president of the American Heart Association, agreed, pointing to the high level of expertise held by operators and centers involved in the recent successful clinical trials.

“There’s a concern out there that now that the evidence-based guidelines recommend clot retrieval and stent retrieval acutely in stroke that others who are less well trained will start trying to use these devices,” he told TCTMD.  “If we start moving to people who are less well trained, we could derail a lot of the success that we’ve seen already with these trials. The trials only worked when the right people were doing the procedure in the right patient at the right time.”

The new document is important, he said, in that it “really emphasizes the need for neurological training in those who are going to be moving forward with catheter interventions for stroke and stroke prevention.”

Donald Frei, MD, president of the Society of NeuroInterventional Surgery, which took the lead in writing the document, told TCTMD that the guidance strengthens prior recommendations by adding the weight of multiple international societies.

Endovascular treatment for ischemic stroke—with stent retrievers, in particular—received a major boost after the results of 3 trials reported last year at this meeting showed improvements in functional outcomes over IV thrombolytic therapy alone in patients with emergent large vessel occlusions.

Together with MR CLEAN, reported in late 2014, and REVASCAT, reported in April 2015, the trials established mechanical thrombectomy as the standard of care in these patients. Use of stent retrievers received a strong recommendation for select patients in a June 2015 update to guidelines from the American Heart Association/American Stroke Association.

The recommendations made in the current consensus document set a high bar for operators performing acute stroke interventions. The authors note that most of the interventions in the 5 successful trials were performed by experienced neurointerventionalists, including interventional neuroradiologists, endovascular neurosurgeons, and interventional neurologists, in centers with 24-hour availability, endovascular capability, and expertise in vascular neurology and neurocritical care. Those factors are “paramount to achieving good clinical outcome,” they say.

“Hence,” they write, “there is a clear rationale for formal training in both clinical neuroscience and interventional neuroradiology.”

Physician, Hospital Requirements Outlined

The path to getting the appropriate training for performing endovascular procedures will vary by country, “but the consensus is to mandate adequate training to perform emergent endovascular stroke intervention,” the authors note. “These cognitive requirements consist of baseline training and qualifications as well as ongoing professional education, which are essential for safe and efficient patient management.”

Baseline training should consist of a residency in radiology, neurology, or neurosurgery with documented experience in diagnosis and management of acute stroke, interpretation of cerebral arteriography and neuroimaging with supervision by a board-certified neuroradiologist, neurologist, or neurosurgeon, according to the document. If such training is not received in residency, another period of at least a year must be spent training in clinical neurosciences and neuroimaging.

After that initial training, physicians should receive dedicated training in interventional neuroradiology under the direction of a neurointerventionalist at a high-volume center lasting at least 1 year.

The authors suggest a minimum of 16 hours of stroke-specific continuing medical education every 2 years to maintain qualifications after successful completion of training and recommend participation in an ongoing quality assurance and improvement program and national registries.

In terms of performance measures, the authors suggest that physicians should be aiming for successful recanalization (modified TICI 2b or 3) in at least 60% of cases, embolization to a new territory in less than 15%, and symptomatic intracranial hemorrhage in less than 10%.

Because successful endovascular treatment occurs in the context of a multidisciplinary team, the authors say, patients should be treated in centers with 24/7 access to the following:

• Adequately equipped angiography suites
• Capability to handle complications
• Dedicated stroke and intensive care units
• Vascular neurology, neurocritical care, and neurosurgery (including vascular neurosurgery) expertise
• All relevant imaging modalities

Some experts have suggested that physicians from other specialties, including interventional cardiology, might be needed to meet demand for endovascular therapy after the success of the clinical trials because there are not enough neurointerventionalists to go around. If adhered to, the standards outlined in this consensus document appear to make that an unlikely approach.

“[The guidance is] not directly rebutting anything that anyone else is saying but clearly you need expertise in your field to be able to safely treat patients,” Frei said.

Sacco said that even though neurointerventionalists are relatively few in number compared with interventional cardiologists, there is growing interest in neurointervention among vascular neurology trainees.

“I think given more time, the number of neurointerventionalists will rapidly increase and we will have greater capacity to treat these patients,” he said.

But Frei said that there are enough neurointerventionalists in the United States right now—about 1,000—to handle the workload. “There are a lot of systems and processes that need to be perfected but… there are enough physicians out there to take care of these patients,” he said.

The consensus document was published simultaneously in the American Journal of Neuroradiology, the eJournal of the European Society of Minimally Invasive Neurological Therapy (EJMINT), Interventional Neuroradiology, the Journal of Interventional Neurology, the Journal of Neuroendovascular Therapy, the Journal of NeuroInterventional Surgery, Neuroradiology, and Neurosurgery.