Neuro clot removal device bests older model for large vessel occlusions

Published date : 03 September 2012
Article date : 03 September 2012

Cardiovascular Business hosts an interesting article on trial results which indicate that patients who have had large vessel occlusion strokes but are ineligible for (or refractory to) intravenous recombinant tissue plasminogen activator should be treated with the Trevo Retriever instead of the Merci Retriever. This is according to the TREVO 2 investigators who have presented the results at the European Society of Cardiology Congress in Munich. The study was also published online in the Lancet.

While rt-PA is the standard of care for treatment of acute ischemic stroke, it has “limitations,” according to the study authors, including a short therapeutic window that restricts more widespread adoption and poor reperfusion rates in the setting of extensive clot burden. As the only alternative to medical therapy, current mechanical devices are unable to achieve recanalization in up to 20 to 40% of large vessel occlusion strokes.

In this open-label, randomised controlled trial, Raul G. Nogueira, MD, professor of neurology and neurointerventionalist at Emory University School of Medicine in Atlanta, and colleagues compared the efficacy and safety of the Trevo Retriever (Stryker Neurovascular), a stent-like device, with its FDA-cleared predecessor, the Merci Retriever (Stryker Neurovascular) by recruiting patients at 26 sites in the U.S. and one in Spain.

The TREVO 2 (Thrombectomy Revascularization of Large Vessel Occlusions in Acute Ischemic Stroke) trial included adults age 18 to 85 years with angiographically confirmed large vessel occlusion strokes and National Institutes of Health Stroke Scale scores of 8 to 29 within eight hours of symptom onset. The researchers randomly assigned patients (1:1) with sequentially numbered sealed envelopes to thrombectomy with Trevo or Merci devices. They stratified randomization by age (at least 68 years vs. 69 to 85 years) and NIHSS scores (at least 18 vs. 19 to 29) with alternating blocks of various sizes.

The primary efficacy endpoint, assessed by an unmasked core laboratory, was thrombolysis in cerebral infarction (TICI) scores of 2 or greater reperfusion with the assigned device alone. The primary safety endpoint was a composite of procedure-related adverse events. The researchers conducted the analysis through intention to treat.

Between Feb. 3, 2011, and Dec. 1, 2011, Nogueira et al randomly assigned 88 patients to the Trevo Retriever group and 90 patients to Merci Retriever group. In the study, 86% of patients in the Trevo group and 60% in the Merci group met the primary endpoint after the assigned device was used. Also, incidence of the primary safety endpoint did not differ between groups (15 percent of patients in the Trevo group vs. 23% in the Merci group).

While the safety profiles were similar with both devices, vessel perforations were almost 10 times more common with the Merci retriever (10 percent) than they were with the Trevo retriever (1 percent). The researchers attributed this perforation rate to a less effective recanalization of the artery, and Trevo is usually deployed by unsheathing the microcatheter compared with the active pushing required with Merci.

Promising results from the SWIFT trial presented at ESC.12 showed the Solitaire Flow device’s (Covidien) superiority over the Merci Retreiver. Nogueira served as a member of the steering committee for SWIFT. The study authors concluded that their trial showed that the Trevo Retriever “was superior to the Merci Retriever for arterial revascularization in terms of reperfusion to TICI 2 or greater in the setting of acute ischemic stroke. 

Source: Cardiovascular Business, written by Justine Cadet, 28th August 2012 

Read the full article here 

Back to Listings

WhichMedicalDevice is a FREE resource created by clinicians for clinicians.

Registration is free and gives you unlimited access to all of the content and features of this website.

Find out more...

Please sign in to view this content...

I have forgotten my password
Not a Member?

Registration is free and gives you unlimited access to all of the content and features of Which Medical Device. Find out more...

Why Register

Which Medical Device is a community of clinicians sharing knowledge and experience of the devices and procedures we use on a daily basis. We ask that our members register with us so that we can maintain the unbiased and independent nature of our content. Registration is quick and free.

We do not make your details available to any third parties nor do we send unsolicited emails to our members. You can read our Privacy Policy here.