Blood Clot Retrieval Now Recommended for Specific Stroke Patients
October 6th, 2016
CHAPEL HILL, NC – After all of the discussion, it’s now official: Key cardiovascular groups now recommend using a stent retrieval device to remove blood clots in certain stroke patients who have clots obstructing the large arteries supplying blood to the brain.
In the focused update published recently in the journal Stroke, the American Heart Association and American Stroke Association endorse that course of treatment in specific cases.
Intravenous delivery of the clot-busting medication tissue plasminogen activator (tPA) within a few hours after ischemic stroke symptoms appear still is advised as optimal initial treatment in most cases.
"What we've 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 tPA is given," said lead author William J. Powers, MD, the H. Houston Merritt distinguished professor and chair of the department of neurology at the University of North Carolina at Chapel Hill.
Results from randomized clinical trials published since 2013, when the last treatment guidelines were issued, are analyzed in the update.
The complex clot-removal procedure involves puncturing an artery in the groin and threading a thin wire tube up into the brain until it reaches the blocked vessel in one of the large arteries. The clot is retrieved, then removed, as the tube is pulled out.
"This additional treatment is more difficult than tPA, which can be given by most doctors in the emergency room," Powers pointed out.
The procedure, which should be initiated within six hours of the onset of stroke, only can be performed in specialized facilities such as Comprehensive Stroke Centers or some Primary Stroke Centers, he added, so one challenge is getting patients to the right hospital in time.
According to the focused update recommends, the stent retriever should be used to remove clots only in adult stroke patients who:
- have no significant disability prior to the current stroke
- received tPA within 4.5 hours of symptom onset
- have a clot blocking a large artery supplying blood to the brain
- had an acute, severe stroke
- have imaging showing more than half of the brain on the side of the stroke is not permanently damaged
- can have the procedure start within six hours after symptom onset
Suggesting the benefits substantially outweigh the potential risks in patients meeting the criteria, the evidence backing the new recommendation received the highest rating.
The use of stent retrievers is indicated in preference to other mechanical thrombectomy devices, although the focused update 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.