Background The development of malignant cerebral edema (MCE) after large-vessel occlusion mechanical thrombectomy (MT) with the ensuing requirement for decompressive craniectomy is a dreaded outcome of stroke. We analyzed factors associated with the development of malignant cerebral edema following mechanical thrombectomy.

Methods We performed a retrospective analysis of anterior cerebral circulation large vessel occlusion cases that underwent MT from April 2012 to November 2019 at single comprehensive stroke center. Data included patient demographics, presenting NIHSS score, vessel occlusion site, onset-to-revascularization timing, presenting blood glucose, 90 day modified Rankin Scale (mRS), post-procedural intracerebral hemorrhage (PH1 or PH2), and post-procedural development of MCE (midline shift greater than 5 mm associated with neurological deterioration after greater than 50% infarction of the MCA territory). Multi-variate logistic regression analyses were performed to determine significant predictors of malignant „cerebral edema and poor functional outcome (mRS 3–6) at 90 days.

Results 400 patients were included in the analysis. 42 (10.5%) patients developed MCE following mechanical thrombectomy with 26 (6.5%) patients undergoing decompressive craniectomy. Significant independent predictors of MCE following MT included: NIHSS (OR 1.10, 95% CI: 1.03–1.18; p=0.008), tPA administration (OR 2.38 95% CI: 1.04–5.46; p=0.041), 4 or more thrombectomy passes (OR 5.25, 95% CI: 1.53–17.94; p=0.008), and initial stress glucose ratio (OR 14.92 95% CI: 3.95–56.43; p<0.001). Significant predictors associated with decreased risk of MCE included: M1 occlusion compared to ICA occlusion (OR 0.40 95% CI: 0.18–0.88; p=0.022) and TICI 2C/3 recanalization (OR 0.27, 95% CI: 0.09–0.78; p=0.015). Significant predictors of a poor functional outcome included: age (OR 1.05, 95% CI: 1.03–1.07; p<0.001), NIHSS (OR 1.10, 95% CI: 1.05–1.15; p<0.001), initial stress glucose ratio (OR 4.49, 95% CI: 1.60–12.61; p=0.004), intracerebral hemorrhage (PH1 or PH2) (OR 4.74, 95% CI: 1.20–18.69; p=0.026) and MCE (OR 6.56, 95% CI: 2.00–21.59); p=0.002). The sole significant predictor against a poor functional outcome at 90 days was TICI 2C/3 recanalization (OR 0.17, 95% CI: 0.07–0.38; p<0.001).

Conclusion Our data demonstrate an association of malignant cerebral edema with ICA occlusion, higher presenting NIHSS scores, tPA administration, 4 or more thrombectomy passes, and a high initial stress glucose ratio. Malignant cerebral edema is associated with poor functional outcome at 90 days. Further investigation of causes of malignant cerebral edema after MT are warranted.

Disclosures G. Cannarsa: None. A. Wessell: None. T. Chryssikos: None. K. Kim: None. J. Stokum: None. H. Carvalho: None. T. Miller: None. D. Gandhi: None. G. Jindal: None.