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A novel thrombectomy, or ‘stent on a wire,’ device continues to show positive results in acute stroke patients, achieving high rates of complete revascularization and good outcomes, especially in patients who have received previous intravenous tissue plasminogen activator (tPA). Results of a retrospective study were published online July 31, 2012, ahead of print in Stroke.

Researchers led by Antoni Dávalos, MD, of the Hospital Universitari Germans Trias i Pujol (Barcelona, Spain), assessed 141 consecutive patients presenting with acute ischemic stroke secondary to large artery occlusion. The patients were treated at 6 European centers with the Solitaire FR device (Covidien, Irvine, CA) as the first-line device to restore blood flow.

Featuring a wire attached to a self expanding stent, the Solitaire can be fully deployed and then retrieved, capturing and removing clot along the way. First, a balloon guide catheter is placed proximal to the intracranial occlusion, followed by delivery and deployment of the Solitaire device over the thrombus through an 18 to 27 microcatheter. The balloon guide catheter is inflated to provide proximal internal carotid occlusion and flow arrest during recovery, after which the Solitaire device and microcatheter are slowly recovered as a unit under constant aspiration with a 60-mL syringe through the balloon guide catheter. The Solitaire is currently CE Mark approved for use in the flow restoration of ischemic stroke patients who are ineligible for or who fail IV tPA therapy.

Successful Revascularization, Neurologic Recovery

The device demonstrated a 97.8% technical success rate in reaching the occlusion site and achieved successful revascularization in 85% of arterial occlusions. The median number of passes for all patients was 1, with 77% of procedures achieving successful revascularization within 1 or 2 passes. Median time from groin puncture to successful revascularization was 40 minutes.

Good early neurologic outcome at 24 to 48 hours (NIH Stroke Scale improvement ≥ 4 points) was achieved in 55% of patients, with 41% showing a dramatic improvement of at least 10 points or full neurologic recovery (NIH Stroke Scale 0-1). Good functional outcome (modified Rankin Scale ≤ 2) at 3 months was achieved in 55% of patients.

The rate of neurologic recovery from 24 hours after the procedure to 3 months of follow-up was higher in the 74 patients (52%) treated with IV tPA than in those who did not receive the thrombolytic (table 1), resulting in a higher rate of favorable functional outcome in such patients at 3 months (66% vs. 42%; P < 0.01).

Table 1. Median Quartile NIH Stroke Scale Scores

^a P ≤ 0.01 between IV tPA and no IV tPA.

At 3 months, mortality was 18%. Causes of death were predominantly stroke-related (n = 11), with none attributed to the Solitaire device.

Advancement for Those with Few Options

The current results add to findings from the randomized SWIFT trial, presented at the American Stroke Association 2012 International Stroke Conference in New Orleans, LA. In the study, the Solitaire system cut mortality in half compared with the older Merci retriever device (Concentric Medical, Mountain View, CA) in acute stroke patients.

Dr. Dávalos and colleagues note that the Solitaire device should be part of the “armamentarium of acute stroke intervention tools because complete thrombus removal is safely achieved in many patients within a short time.” While IV tPA is still the best option if delivered under 4.5 hours, ineligible patients and those who fail tPA show significant betterment with the thrombectomy device that represents a “substantial advancement of outcome in [those] who before had few, if any, options.”

For the future, “recruitment in randomized trials of endovascular therapy compared with standard therapy is urgently needed,” the authors write.

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