The Trevo Stent Retriever is a tiny stent-shaped medical device that is attached to a thin wire. In a minimally invasive procedure that utilizes X-ray, the physician navigates the retriever from the femoral artery, which is located in the upper leg, to the blocked blood artery in the brain. The retriever is designed to ensnare the blood clot and remove it from the body. Originally cleared by the FDA in 2012, the Trevo Retriever has been used in thousands of patients worldwide.
Imahori et al., retrospectively reviewed 50 patients with acute middle cerebral artery occlusion treatment with the Trevo Stent retriever. Patients were divided into groups that achieved (1st-pass recanalization group, n=21) or did not achieve (non-1st-pass recanalization group, n=29) a modified Thrombolysis in Cerebral Ischemia score of 2b or 3 with the 1st-pass procedure. Patients were also divided into a thromboembolic (n=49) and atherosclerotic (n=11) group by occlusion etiology. They evaluated radiographic findings of the Trevo strut, e.g., degree of stent expansion and filling defect of the thrombus in the strut (in-stent thrombus sign) during the 1st-pass procedure among these groups.
The median stent expansion was significantly greater in the 1st-pass recanalization than non-1st-pass recanalization group (60% versus 34%; P<0.01), and in the thromboembolic than atherosclerotic group (45% versus 31%; P<0.01). The receiver operator characteristic curve shows moderate capacity of the prediction for recanalization and etiology, with an area under the curve of 0.83 and 0.73, respectively. The in-stent thrombus sign was significantly more common in the thromboembolic than atherosclerotic groups (86% versus 10%; P<0.01).
Greater stent expansion was associated with recanalization after thrombectomy. The in-stent thrombus sign may be useful for etiology prediction. These radiographic findings could provide useful real-time feedback during procedure, reflecting the clot-stent interaction 1).