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Two new devices to pluck blood clots out of the brain

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Both approved for clinical use, the Solitaire and the Trevo restore blood flow in stroke victims. New studies show that they're safer and more effective than the current standard tool.

Recent studies reveal how 2 new devices for plucking stroke-causing blood clots out of the brain are safer and more effective than the standard treatment for stroke victims.

And the devices have already been approved for clinical use by the US Food and Drug Administration. The Los Angeles Times reports.

A little history:

In 1996, the FDA approved tissue plasminogen activator (tPA) for the dissolution of blood clots in the brain. It was considered the primary treatment for stroke victims, but it must be used within 3 after the stroke and it’s not effective for dissolving larger blood clots.

In 2004, the FDA approved the first mechanical system for removing clots from the brain. The Merci Retrieval System can be used after the initial 3-hour window and with larger clots. A corkscrew-like wire is threaded through blood vessels from the groin to the brain, where the wire is screwed into the clot.

Now, there are 2 new FDA-approved devices that restore blood flow in blocked brain arteries that are safer and more effective than the Merci device.

Both are expandable wire-mesh systems much like the wire stents that are used to hold blood vessels open after balloon angioplasty. The collapsed mesh is threaded through blood vessels to the site of the clot, where it is opened and moved forward to engulf the clot. It is then collapsed again and withdrawn, taking the clot with it.

The Solitaire Flow Restoration Device (pictured) was developed at the University of California, Los Angeles, and marketed by Covidien of Mansfield, Mass.

  • 113 stroke patients at 18 hospitals were randomly assigned to receive treatment with either the Solitaire or Merci devices within 8 hours of stroke onset.
  • 3 months after treatment, 58% of those treated with the Solitaire device were assessed as having a good neurological outcome, compared to 33% of those treated with the Merci device.
  • 17% of those treated with Solitaire died, compared to 38% of those treated with the Merci device.
  • Watch a video of the Solitaire device here.

The Trevo Pro Retrieval System is marketed by Stryker Neurovascular of Kalamazoo, Mich.

  • Emory University researchers studied 178 patients with large blood clots at 26 U.S. centers and one in Spain, comparing the Trevo device to the Merci device within 8 hours after stroke onset.
  • 40% of the patients treated with the Trevo device had an independent life after treatment, compared to 22% of those treated with the Merci device.
  • 15% of the patients treated with Trevo had an adverse event, compared to 23% in the Merci group.

The devices’ successes were described in two studies released this week in The Lancet and at the European Society of Cardiology Congress in Munich.

[Via Los Angeles Times]

Image: Covidien and UCLA newsroom

Janet Fang

Contributing Editor

Janet Fang has written for Nature, Discover and the Point Reyes Light. She is currently a lab technician at Lamont-Doherty Earth Observatory. She holds degrees from the University of California, Berkeley and Columbia University. She is based in New York. Follow her on Twitter. Disclosure