Groundbreaking studies find that neurointerventional surgery reduces stroke mortality


Two new clinical trials on the treatment of stroke (ESCAPE and EXTEND IA) demonstrate that neurointerventional surgery significantly increases the number of patients who are able to live independently without major neurological disabilities. The ESCAPE study, published 11 February in the New England Journal of Medicine, also shows that neurointerventional surgery reduces stroke mortality by 50%.

ESCAPE (Endovascular treatment for small core and anterior circulation proximal occasion with emphasis on minimizing CT to recanalization times) and EXTEND IA (Extending the time for thrombolysis in emergency neurological deficits – intra-arterial) are two of three studies (together with SWIFT PRIME) that confirm the MR CLEAN study published in the New England Journal of Medicine late last year–which showed that the addition of inside-the-artery clot removal is more effective than IV-administered “clot-busting” tissue plasminogen activator (IV-tPA) treatment alone for the treatment of stroke.


“All three of these studies confirm what we are seeing in everyday practice. In many cases, instead of suffering major neurological disability, patients are able to go home to resume their lives,” says Peter Rasmussen, director of the Cerebrovascular Center, Cleveland Clinic in Cleveland, Ohio, USA, and president of the Society of NeuroInterventional Surgery (SNIS). “Within-the-artery procedures, which are performed by neurointerventional surgeons, are not the appropriate treatment for every patient suffering from stroke, but for those patients experiencing the most severe types of ischaemic strokes, they are life-saving, viable and effective therapies that offer many benefits over traditional treatments, including shorter recovery times and a better chance to return to normal activities.”


ESCAPE is the first study to show that the overall stroke mortality rate was reduced by 50% with neurointerventional surgery, from two in 10 patients for standard-of-care treatment to one in 10. ESCAPE and EXTEND IA showed better outcomes for those patients treated with neurointerventional surgery. In ESCAPE, nearly 30% of patients treated with IV-tPA treatment alone were able to live independently without major neurological disabilities. For patients receiving neurointerventional surgery, that number increased to 53%. EXTEND IA showed even better results, with 71% of patients who received neurointerventional surgery returning to independent living, compared with 40% in the standard treatment group.


According to Peter Mitchell, co-principal investigator of EXTEND IA and the director of neurointervention at the Royal Melbourne Hospital, Australia, two of the key differences in better outcomes for stroke patients were the use of more advanced brain imaging to select patients most likely to benefit and earlier treatment. The Royal Melbourne Hospital, where the EXTEND IA study was conducted, treats approximately 500 ischaemic stroke patients a year and is one of the few stroke centres in the world to treat patients within 20 minutes of arriving in the emergency department.


According to Donald Frei, a neurointerventional surgeon at Radiology Imaging Associates in Denver, USA, and president-elect of SNIS, treatment time is critical. While ESCAPE showed that neurointerventional surgery can be performed up to 12 hours from the onset of stroke, the success of the trial can be credited to fast treatment and the use of brain and blood vessel imaging. In ESCAPE, researchers were on average two hours faster in opening the blocked blood vessels than in previously reported trials.


“These positive studies are important milestones in the transformation of care for stroke patients, but it’s also important to understand that the comprehensive stroke centres that participated excel in providing this type care,” says Frei. “The results may not be replicable in every hospital. It’s important that when stroke occurs, the disease is identified quickly and patients are transported to facilities that are equipped to provide the best evidence-based interventions for ischaemic and haemorrhagic stroke management.”


ESCAPE included 22 sites worldwide and patients in the USA, UK, Ireland and South Korea and evaluated the effect of endovascular treatment for patients with acute ischaemic stroke caused by a clot obstructing one of the major intracranial arteries. The study was ended early because it crossed the pre-specified boundary for efficacy. The study included 316 patients who fit the criteria for neurointerventional surgery and arrived for treatment within 12 hours of their stroke who were randomised to standard medical care (which included the IV-tPA where appropriate) or standard medical care plus neurointerventional surgery. 


The EXTEND IA trial compared IV-tPA to IV-tPA and neurointerventional surgery in patients with acute ischaemic stroke receiving IV therapy within 4.5 hours of stroke onset. Patients were selected using CTA and CTP to identify those with large vessel occlusion and small core infarct with significant volume of “threatened” tissue. The trial was stopped early because of efficacy when 70 of the intended 100 patients had been randomised (35 to each arm) after the presentation of the MR CLEAN results prompted the DSMB to perform a pre-specified analysis.