It used to be that stroke victims were immediately treated with tissue plasminogen activators (tPA) to dissolve the clots that formed in the brain.
But if more than three hours had passed, no dice, no guarantees, and it wasn’t effective for dissolving large clots, according to a story written by Janet Fang.
She noted that, in 2004, the FDA did approve the first mechanical system for removing clots from the brain, the Merci Retrieval System, which took care of those two problems and could be used after the initial three hour window had passed, and with larger clots.
But, two new devices with better survival odds for picking stroke-causing blood clots out of the brain have been approved for clinical use by the US Food and Drug Administration (FDA), according to The Los Angeles Times, Fang reported.
Cardiologists today have their choice of two devices, both of which are expandable wire-mesh systems, resembling delicate twisted wire, much like the wire stents that are used to hold blood vessels open after a balloon angioplasty. One, the Solitaire Flow Restoration Device, was developed at the University of California, Los Angeles, and marketed by Covidien of Mansfield, Mass.
Fang described the device as “a corkscrew-like wire threaded through blood vessels from the groin to the brain, where the wire is screwed into the clot,” which does not sound very pleasant.
“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 It is then collapsed again and withdrawn, taking the clot with it,” Fang wrote.
Fang released some compelling stats: 58 percent of those treated in a study with the Solitaire device, some up to eight hours after the stroke, were found to have “a good neurological outcome,” compared to 33 percent of those treated with the Merci device.
17 percent of those treated with Solitaire died, compared to 38 percent of those treated with the Merci device.
The second device, the Trevo Pro Retrieval System, marketed by Stryker Neurovascular of Kalamazoo, Mich., works much like the Solitaire device, surrounding and roping off the clot, then pulling it free.
According to Diagnostic and Interventional Cardiology, the device restored blood flow after the procedure in 92 percent of the cases, compared to the Merci at 76.7 percent.
The devices’ successes were described in two studies released this week in The Lancet and at the European Society of Cardiology Congress in Munich.
Edited by
Jamie Epstein
