New Blood Clot Device 40% More Effective

SOLITAIRE Blood clot removing device more effective than mechanical FDA approved clot remover

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) An experimental device designed to remove blood clots from blocked vessels after a stroke has successfully outperformed a mechanical U.S. Food and Drug Administration-approved device during a trial.

The SOLITAIRE Flow Restoration Device was found to be more effective than the MERCI retriever during the first U.S. clinical trial to test the device.

"Seek immediate stroke treatment."

SOLITAIRE features a self-expanding stent that mechanically removes blood clots by trapping the clot in an inserted catheter, helping restore blood flow. Though not approved in the U.S., SOLITAIRE already is approved for use in Europe.

The MERCI retriever uses a small corkscrew design, guided by a balloon-tipped wire that catches and removes the clot.

Dr. Jeffrey L. Saver, lead author of the study, professor of neurology and director of the Stroke Center in the Geffen School of Medicine at the University of California, said the findings herald "a new era in acute stroke care." He said the highly effective device would have a "game-changing result."

During the Solitaire With the Intention for Thrombectomy (SWIFT) trial, researchers enrolled 113 stroke patients at 18 hospitals. They were randomly selected to have a clot removed by either device within eight hours of the onset of a stroke between February 2010 and February 2011.

The average patient age was 67, and 68 percent of patients were men. About 40 percent of participants had first received clot-busting drugs without improvement.

More commonly, patients receive a clot-busting drug within 4.5 hours of the onset of a stroke. However, when the drugs are not effective or cannot be used, mechanical clot removal is often the method used.

The trial was ended one year earlier than planned after investigators found significantly better outcomes than they had expected. The experimental device opened blocked vessels without causing brain bleeding in 61 percent of patients as compared to 24 percent of patients receiving treatment from the device already on the market.

The number of patients who survived three months after the procedure also was significantly better with the experimental device. SOLITAIRE had a 17.2 percent mortality rate three months after a stroke as compared to 38.2 percent with MERCI.

Only 2 percent of SOLITAIRE patients experienced bleeding in the brain compared to 11 percent of MERCI patients, and patients receiving SOLITAIRE were more likely to have their vessels opened on the first attempt, lowering the number of subsequent tries or additional drugs.

At 90 days after the procedure, the number of overall adverse events were similar. However, 58 percent of SOLITAIRE patients had good mental and motor functioning at three months as compared to only 33 percent of MERCI patients.

The amount of time between the onset of stroke symptoms and the clot retriever treatment was on average 4.9 hours for SOLITAIRE and 5.3 hours for MERCI. The study results account for the time difference.

Covidien, the SOLITAIRE manufacturer, funded the study.

The study was presented Friday at the American Stroke Association’s 2012 International Stroke Conference in New Orleans.

Reviewed by: 
Review Date: 
February 3, 2012
Last Updated:
February 5, 2012