Value of Thrombus Imaging Characteristics as a Guide for First‐Line Endovascular Thrombectomy Device in Patients With Acute Ischemic Stroke

Background It has been suggested that selection of a first‐line endovascular thrombectomy device, that is, contact aspiration (CA) or stent retriever (SR) thrombectomy, could be based on thrombus type. Thrombus composition and mechanical behavior can partially be predicted with thrombus computed tomography (CT) characteristics. We aimed to assess the influence of thrombus CT characteristics on the association between first‐line device and outcomes of endovascular thrombectomy. Methods For patients enrolled in the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands) Registry between March 2014 and November 2017, we assessed thrombus density, thrombus length, and presence of hyperdense artery sign on thin‐slice (≤2.5 mm) admission CT. We used regression models to estimate the relationship between first‐line endovascular thrombectomy device (CA versus stent retriever) and first‐pass reperfusion (FPR, expanded Thrombolysis in Cerebral Infarction score 2C‐3 after first attempt), final reperfusion, procedure duration, 24‐hour National Institutes of Health Stroke Scale, and 90‐day modified Rankin scale score and tested for interaction of thrombus characteristics with first‐line device by adding interaction terms. Results Of 703 included patients, 520 (74%) received first‐line stent retriever and 183 (26%) first‐line CA. Overall, the first‐line device was not associated with FPR (adjusted odds ratio [aOR], 1.32 [95% CI, 0.88–1.98]). In patients with thrombus density below the median (<50 Hounsfield units), FPR was more often achieved with CA than with a stent retriever (34% versus 24%, aOR, 1.95 [95% CI, 1.09–3.50]), whereas in patients with thrombus density above the median (≥50 Hounsfield units), first‐line device was not associated with FPR (aOR, 0.90 [95% CI, 0.50–1.62]). The interaction between thrombus density as a continuous variable and first‐line device on outcome was not significant ( P =0.38). There was also no interaction between first‐line device and the other thrombus characteristics for FPR or the other outcomes. Conclusion Our study does not provide evidence that the association between first‐line thrombectomy device and endovascular thrombectomy outcomes depends on thrombus CT characteristics. Based on our results, there are no arguments for thrombectomy device selection based on thrombus CT characteristics. A possible better performance of CA in low‐density, fibrin‐rich clots needs further study.