乌鸦传媒

A radially adjustable stent retriever appeared effective and safe among stroke patients eligible for mechanical thrombectomy in the 160-patient .

Operators achieved successful revascularization (mTICI 2b-3) within three passes in 84.6% of cases with the Tigertriever device, which was better than the 73.4% historical rate from pivotal trials for the FDA-approved Solitaire and Trevo (P<0.01 for superiority), according to Jeffrey Saver, MD, of the University of California Los Angeles, and colleagues.

Tigertriever's composite 18.1% rate of safety events -- namely symptomatic intracerebral hemorrhage at 24 hours (1.7%) and all-cause mortality by 90 days (18.1%) -- also met superiority criteria against the 20.4% from historical controls, the investigators reported at the American Stroke Association's virtual . A full manuscript was published simultaneously in Stroke.

Notably, embolization to uninvolved territories stayed low at 2.6% across the 160 cases.

Existing stent retrievers on the market are limited by failure to achieve successful reperfusion in a quarter of patients and failure to achieve excellent reperfusion in two-thirds. Operators have also reported embolization to a new territory in 7.3% of patients, and symptomatic intracranial hemorrhage in 4.4%, based on past trials cited by Saver and colleagues.

The Tigertriever was designed to allow the interventionalist to control radial device expansion and force according to visual and tactile feedback during endovascular therapy. As such, they can get a better hold of the clot inside the mesh.

"Having the ability to control radial force of the stent-retriever device is novel and a welcome addition to the neurointerventionalist's toolbox for stent-retriever thrombectomy," commented Hesham Masoud, MD, of Upstate University Hospital and SUNY Upstate Medical University in Syracuse, New York.

In the study, operators had their choice of using other mechanical thrombectomy devices, angioplasty, intra-arterial thrombolysis, and intracranial stenting after three attempts with the Tigertriever.

Use of such rescue therapy reached 28.2%, "reaffirming the need to have different tools handy to achieve optimal revascularization," said Masoud, who was not involved with the study.

"I believe that direct aspiration is increasingly being employed as a primary approach (likely due to ease of technique, cost, and minimal clot disruption by avoiding traversing lesion). It would be interesting to see a comparison of this novel stent-retriever with aspiration devices," he told 乌鸦传媒 in an email.

TIGER (Treatment With Intent to Generate Endovascular Reperfusion) was a prospective single-arm study conducted at 16 U.S. sites and one center in Israel. There was a lead-in phase, during which centers gained experience with the device, and a main study phase afterward.

Mean age for the 160 participants was 65, and 61.5% were men. All had acute ischemic stroke due to large vessel occlusion (LVO) scoring 8 or above on the NIH Stroke Scale and were enrolled within 8 hours of stroke onset.

Two-thirds of participants received tPA; it took 95 minutes to administer the lytic among those who did.

Two sizes of the novel device were tested: the Tigertriever with an internal diameter of 0.021 inches, and the smaller Tigertriever 17 at 0.017 inches.

For each pass during the procedures, a new Tigertriever device was used. Successful reperfusion with just a first pass reached 57.8%.

Patients had a good clinical outcome (modified Rankin Scale 0-2) at 90 days in 58% of cases. This was superior to the 43% seen among historical controls (P=0.0006).

Outcomes were comparable across study phases and target vessel sizes.

Given that each Tigertriever could only be used once in the study, Masoud raised concerns about potential device fragility. "It would be worthwhile to follow up on device-specific registry data to see how it performs."

"Overall I think this is a promising addition to the thrombectomy tool kit and look forward to incorporating it into practice," he continued.

Comment