The treatment of acute ischemic stroke (AIS) in the setting of intracranial large artery occlusion (LAO) with intravenous tissue plasminogen activator (IV-tPA) is associated with low rates of recanalization and high rates of neurological morbidity and functional dependence. Endovascular intervention, particularly mechanical thrombectomy, has shown promise over the last couple of years as a therapeutic adjunct to IV-tPA for the treatment of acute LAO. The implementation of endovascular mechanical therapies has enabled the histological analysis of thrombi retrieved from AIS patients. Neutrophil extracellular traps (NETs) have recently been identified as key players involved in the formation of thrombi of various origins. It has been suggested that the content of thrombus NETs may be responsible for reperfusion resistance in AIS patients. Other factors related to clot stabilization and fibrinolysis may also contribute to efficacy of arterial revascularization. Dr. Manuel Navarro-Oviedo of Spain and others sought to analyze the thrombus composition, assessing the presence of NETs, thrombin activatable fibrinolysis inhibitor (TAFI), and FXIII and their relationship with successful revascularization after mechanical thrombectomy in AIS, through the collection of 45 thrombi.
18% of AIS patients did not achieve complete revascularization after mechanical thrombectomy. NETs and TAFI were detected in almost all thrombi, but their content was not associated with successful recanalization. Notably, FXIII within the thrombus was increased in patients who failed to recanalize after mechanical thrombectomy. Quantitative measurement of thrombus FXIII content correlated with NETs. From receiver operating characteristic curves, the investigators established a cutoff value for FXIII and complete recanalization (2.7, sensitivity = 71% and specificity = 81%).
Dr. Navarro-Oviedo concluded that “FXIII is an important constituent of cerebral thrombi associated with failure in complete recanalization after mechanical thrombectomy. Our study found for the first time a relationship between the FXIII thrombus content and the revascularization rate after ischemic stroke. Therefore, suggesting that FXIII might be a key player in thrombolysis resistance representing a novel revascularization approach for ischemic stroke.”