Association between microvascular cerebral circulation time, malignant brain edema and outcome after successful thrombectomy.

Abstract

Prolonged microvascular cerebral circulation time (mCCT) after endovascular thrombectomy (EVT) may reflect microvascular cerebral circulation impairment. The associations among mCCT, the development of malignant brain edema (MBE), and the functional outcome after successful recanalization (mTICI ≥ 2b) in large vessel occlusion stroke (LVOS) remain unclear. We performed a retrospective analysis of 358 consecutive anterior circulation LVOS patients who achieved successful EVT. mCCT was measured intraprocedurally on DSA using syngo iFlow (Siemens Healthineers). MBE was assessed on follow-up imaging within 72 h. Functional outcome was modified Rankin Scale (mRS) score ≤ 2 at 90 days. Associations were tested using logistic regression and mediation analysis. MBE occurred in 42 patients (11.7%). Patients with MBE had significantly prolonged mCCT (median 4.7 s, IQR: 3.6-5.4) vs those without (3.4 s, IQR: 2.8-4.2; p < 0.001). Prolonged mCCT independently predicted MBE (aOR = 2.703; 95% CI: 1.833-3.985; p < 0.001) and unfavorable outcome (mRS > 2; aOR = 3.450; 95% CI: 2.402-4.954; p < 0.001). Adding mCCT to a model (collateral status, admission NIHSS, ASPECTS) significantly improved MBE prediction discrimination (AUC 0.915 vs 0.868; p = 0.015). Mediation analysis showed MBE did not significantly mediate the mCCT-functional outcome relationship (indirect effect coefficient = 0.001, p = 0.200; proportion mediated 7.6%). Prolonged mCCT is a potential predictor of both MBE and unfavorable functional outcome after successful EVT for LVOS. While associated with increased MBE risk, mCCT's impact on prognosis appears largely independent of MBE. mCCT is a valuable intraprocedural biomarker for prognostication and guiding early post-EVT management. Question How does prolonged mCCT after a successful EVT relate to MBE and functional outcomes? Findings Prolonged mCCT is a potential predictor of MBE and unfavorable functional outcomes. MBE does not significantly mediate mCCT's effect on outcomes. Clinical relevance Intraprocedural mCCT measurement identifies high-risk patients for early intervention (e.g., intensive monitoring, osmotherapy). It directly reflects microvascular injury, offering a novel biomarker for individualized post-EVT management.