For the fist time, the American Heart Association and American Stroke Association are recommending the use of clot-removing devices for some stroke patients.
These stent devices would be used to remove blood clots that obstruct large arteries that supply blood to the brain. The primary treatment for clot-caused (ischemic) stroke remains intravenous delivery of the medication tissue plasminogen activator (tPA), but the new recommendations suggest a combination treatment for select patients.
"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 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.
In the clot-removal procedure, an artery is punctured in the groin area and thin wire tube is threaded up into the brain until it reaches a blocked blood vessel in a large artery. The wire (which also has a wire mesh called a "stent retriever"), is then pushed into the clot and the mesh is expanded to grab it.
"This additional treatment is more difficult than tPA, which can be given by most doctors in the emergency room," Powers said. "Clot removal with a stent retriever requires a specialized center, such as Comprehensive Stroke Centers, or other healthcare facilities with specially trained people including some Primary Stroke Centers. 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 new recommendations suggest patients have their clots removed with a stent if: they have no disability prior to the stroke; they received tPA within 4.5 hours of symptom onset; they have a clot blocking a large artery to the brain; they are at least 18 years old; can have the procedure within six hours of symptom onset; and they have had an acute stroke; imaging reveals more than half of the brain associated with the stroke is not damaged.
"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 findings were published in a recent edition of the Journal of the American Heart Association.
