Objective: The aim of this study was to evaluate thrombus composition and its association with clinical, laboratory, and neurointerventional findings in patients treated by mechanical thrombectomy due to acute large vessel occlusion.
Methods: From August 2015 to June 2016, 72 patients were treated in our hospital by mechanical thrombectomy using stent retriever and/or aspiration catheter. Retrieved thrombi underwent semiquantitative analysis to quantify red blood cells, white blood cells, and fibrin by area. We divided patients into two groups as fibrin rich group or erythrocyte rich group according to predominant composition in thrombus. Two groups were compared with respect to imaging, clinical, and neurointerventional data.
Results: Histopathologic analysis of retrieved thrombus from 37 patients with acute stroke due to internal carotid artery, middle cerebral artery, or basilar artery occlusion was performed. Erythrocyte rich thrombi were present in 13 (35%) of cases, and fibrin rich thrombi in 24 (65%). Cardioembolic etiology was significantly more in patients with fibrin rich thrombi than those with erythrocyte rich thrombi (79% vs. 38%; p=0.01). All other clinical and laboratory characteristics did not differ. Patients with fibrin rich thrombi had greater number of recanalization maneuvers (2.8 ± 1.2 vs. 1.8 ± 1.6, p=0.04) and longer interval time between puncture and recanalization (62 ± 33.6 minutes vs. 42 ± 21.3 minutes; p=0.04). There is no significant difference in occluded vessels and mechanical thrombectomy devices between two groups. Patients with fibrin rich thrombi were lower rate of functional independence (mRS score, 0-2) at 90 days (33% vs. 75%; p=0.04).
Conclusion: This study showed that fibirin rich thrombus was associated with extended procedure time, unfavorable clinical outcome and cardioembolic etiology.