Microbleeds after Stent-assisted Coil Embolization of Unruptured Intracranial Aneurysms: Incidence, Risk Factors and the Role of Thromboelastography

Objective: To analyze the incidence and risk factors of microbleeds lesions and to use thromboelastography (TEG) to evaluate the relationship between perioperative platelet function and microbleed events in patients with unruptured intracranial aneurysms (UIAs) undergoing Stent-Assisted Coil (SAC) embolization. Methods: We retrospectively enrolled 261 patients with UIAs undergoing SAC embolization between November 2017 and October 2019. All patients received unanimous antiplatelet protocol (aspirin 300 mg and clopidogrel 300 mg). Platelet function was evaluated by TEG, and magnetic resonance susceptibility-weighted imaging (SWI) was performed for microbleeds detection before and after surgery. Univariate and multivariate logistic regression analyses were used to identify potential risk factors for microbleeds following embolization. Results: Microbleed lesions were identified in 122 of 261 patients (46.7%). Most of the microbleeds were asymptomatic, except for 22 patients complaining slight headaches, and 3 patients who developed cerebral hemorrhage after discharge. Among the clinical characters, female, previous intracerebral hemorrhage (ICH) history and TEG parameters variation (higher reaction time (R) and lower maximum amplitude of adenosine diphosphate (MAADP)) were associated with microbleeds occurrence. Subsequent multivariate analysis indicated that gender, hemorrhage history, R, and MAADP were still independent risk factors of microbleeds. The R-value (>7.6 min) and MAADP (<29.2 mm) were predictive values, yielding areas under the receiver operating curve (ROC) of 0.76 (95% CI 0.70 to 0.82) and 0.89 (95% CI 0.86 to 0.93), respectively. Conclusion: The incidence of microbleeds may be high in UIA patients treated with SAC and dual antiplatelet therapy. Lesions occurred more frequently in female patients and patients with ICH history. Among the TEG parameters, the R-value and MAADP were predictors for microbleed events.