A snapshot of several active research areas in stroke intervention
by Bryn Nelson, PhD
Among stroke patients with intracranial stenosis, or the narrowing of arteries within the brain, researchers found that aggressive medical therapy and attention to risk factors outperformed a combination of drugs and percutaneous transluminal angioplasty and stenting (PTAS) in preventing stroke recurrence.11 The immediate conclusions might apply to a specific condition and be due in part to a tricky surgical stenting procedure, but experts including Dr. Likosky say it’s also indicative of the power of medical management when done appropriately. Doctors can readily adopt core elements of this therapeutic intervention, including adding clopidogrel to aspirin for the first three months, and helping patients lower their blood pressure and cholesterol levels.
Advanced imaging techniques like diffusion-weighted MRI (which uses the movement of water as a lens to produce a detailed map of stroke-damaged brain tissues and vessels) are helping doctors determine the best course of therapy. Evidence of a salvageable ischemic brain, Dr. Jensen says, can help make the case for interarterial removal of the obstruction. And finer resolution can help differentiate between a transient ischemic attack (TIA) and a true stroke.
Researchers have examined the potential for a range of medications to limit the amount of neurological damage after a stroke. So far, at least, none have proven to be very effective. “We just haven’t found the magic bullet,” Dr. Jensen says. “Of course, that would be the most wonderful thing in the world because you could put them in people’s houses and say, ‘If you think you’re having a stroke, start taking these pills,’ but we’re just not there yet.”
The standard FDA-approved mechanical clot remover, a helical-shaped device called the Merci Retriever, acts like a corkscrew to spear and dislodge clots, while a machine known as Penumbra does its job through suction. After showing promise in Europe, two next-generation stent retrievers, the Trevo and the Solitaire, could give the established techniques a run for their money in the U.S.
At February’s International Stroke Conference in New Orleans, researchers reported that the Solitaire (sometimes called a concentric retriever, or a “stent on a stick”) significantly outperformed the Merci in several measures of patient outcomes. The randomized, controlled SWIFT clinical trial, in fact, ended earlier than planned because the results were so promising. Clinicians recorded a three-month mortality rate of 17.2% for patients treated with Solitaire, compared with a 38.2% rate among Merci-treated patients. In addition, the trial recorded good mental and motor functions among 58.2% of Solitaire patients at three months, but only among 33.3% of the Merci cohort. At the same conference, researchers reported that a prospective European trial of the Trevo system yielded similarly encouraging results.
The Hospitalist newsmagazine reports on issues and trends in hospital medicine. The Hospitalist reaches more than 25,000 hospitalists, physician assistants, nurse practitioners, residents, and medical administrators interested in the practice and business of hospital medicine.