Stent retrievers now recommended for some stroke patients


For the first time, the American Heart Association/American Stroke Association recommends using a stent retrieval device to remove blood clots in select stroke patients who have clots obstructing the large arteries supplying blood to the brain, according to a new focused update published in the American Heart Association journal Stroke.

The optimal initial treatment for a clot-caused (ischaemic) stroke remains intravenous delivery of the clot-busting medication tissue plasminogen activator (t-PA). When given within a few hours after stroke symptoms, t-PA can dissolve the clot and re-establish blood flow to the brain, limiting stroke disability.

“What we have learned in the last eight months, from six new clinical trials, is that some people will benefit from additional treatment with a stent retrieval device if a clot continues to obstruct one of the big vessels after t-PA is given,” said William J Powers, lead author of the focused update and H Houston Merritt distinguished professor and chair of the department of neurology at the University of North Carolina at Chapel Hill.

The focused update on endovascular treatment of acute ischaemic stroke analyses results from randomised clinical trials published since 2013, when the last treatment guidelines were issued.

“This additional treatment is more difficult than t-PA, which can be given by most doctors in the emergency room,” Powers said.

“Clot removal with a stent retriever requires a specialised centre, such as comprehensive stroke centres, or other healthcare facilities with specially trained people including some primary stroke centres. This treatment has to be done within six hours of the onset of stroke, so in some areas it can be tricky to get you to an appropriate hospital in time.”

The focused update recommends that stroke patients have their clots removed with a stent retriever if they:

  • have no significant disability prior to the current stroke;
  • received t-PA within 4.5 hours of symptom onset;
  • have a clot blocking a large artery supplying blood to the brain;
  • are at least 18 years old;
  • had an acute, severe stroke;
  • have imaging showing more than half of the brain on the side of the stroke is not permanently damaged; and
  • can have the procedure start within six hours after symptom onset.

The evidence backing this new recommendation received the highest rating based on the scientific evidence reviewed, and suggests the benefits substantially outweigh the potential risks in these patients.

“Evidence-based guidelines are based on clinical trials, which tell you that if you have a patient with the same characteristics of those in the trials, on average they will do much better with the treatment than if you treat them another way,” Powers said.

The focused update states that the use of stent retrievers is indicated in preference to other mechanical thrombectomy devices, but notes that the use of mechanical thrombectomy devices other than stent retrievers may be reasonable in some circumstances based on a physician’s clinical judgment.