1142 Timing to Surgery and Volume Reduction in Early Minimally Invasive Removal of Intracerebral Hemorrhages: An ENRICH Post-Hoc Analysis

INTRODUCTION: The Early Minimally Invasive Removal of Intracerebral Hemorrhage (ENRICH) trial has recently established a milestone for surgical intervention in lobar ICHs compared to medical management. METHODS: We conducted a post-hoc study on the ENRICH trial surgical arm, with sub-analyses for lobar and anterior basal ganglia (ABG) ICHs. Interval from last known normal (LKN) to surgery, surgeon’s experience, ICH volume before and after treatment, percentage of hematoma evacuated, target end-of-treatment volume (EOTV) < 15 mL were analyzed, and outcomes were determined as dichotomized modified Rankin scale (mRS; 0-3 vs 4-6) and mortality at 180-day. RESULTS: Median LKN to surgery times were 17.78, 18.72 and 14.92 hours for the overall, lobar, and ABG groups, with an optimal intervention cut-off at 12.78 hours [AUROC: 0.549 (0.456-0.642)] for mRS 0-3. Average preoperative ICH volumes were 54.39, 54.40 and 50.96 mL, a threshold of 62.49 mL predicted a better outcome [AUROC: 0.656 (0.569-0.744)]. EOTV analysis (7.18, 6.90 and 7.72 mL for the groups investigated) revealed a significant threshold at 2.47 mL overall [AUROC: 0.642 (0.554-0.730)] for mRS 0-3 and at 30.42 mL [AUROC: 0.635 (0.516-0.754)] for improved mortality – with a slightly inferior mortality threshold for the ABG group at 21.78 mL (AUROC: 0.601 [0.391-0.811],). Multivariable ordinal regression identified age, preoperative GCS, preoperative and EOTVs as independent predictors of favorable mRS. LKN to surgery time did not show a significant effect in the adjusted model. Finally, EOTV (OR: 1.02 [1.004-1.04]) was also an independent predictor of mortality, other than age (OR: 1.06 [1.01-1.10]) and preoperative GCS (OR:0.82[0.68-0.98]). CONCLUSIONS: Optimal thresholds impacting functional outcome and mortality were established regarding time-to-intervention, preoperative ICH volume, and EOTV. These findings might aid in optimizing patient selection and have significant implications for designing future clinical trials.