Abstract Body: Background: Non-contrast computed tomography (NCCT) markers have been commonly used to characterize hematomas in intracerebral hemorrhage (ICH). This study investigates the relationship between pre-operative imaging markers and clinical outcome following minimally invasive surgical (MIS) ICH evacuation.

Methods: This study included all patients presenting with ICH who underwent MIS ICH evacuation from 2016 to 2021. The presence of spot sign, swirl sign, blend sign, black hole sign, satellite sign, island sign, and cleft was identified on pre-operative CT imaging. Univariate and multivariate analyses were performed between CT markers and variables of operative outcome with R v 4.3.1.

Results: 221 patients met the inclusion criteria. Swirl sign was identified in 127 patients (57%), spot sign in 30 (14%), black hole sign in 60 (27%), island sign in 10 (5%), satellite sign in 63 (29%), blend sign in 32 (14%), and cleft in 59 (27%). On univariate analysis, presence of any hematoma characteristic was correlated with increased intracavitary bleeding score (2.61±1.35 vs. 2.00±1.94, p = 0.027). Spot sign was correlated with increased rate of surgical rebleed (3.7% vs 2.4%, p = 0.021). Satellite sign was correlated with increased rate of surgical rebleed (6.7% vs. 0.7%, p = 0.021) and marginally significant increased residual volume (12±17 mL vs. 8±11 mL, p = 0.066). Presence of a cleft within hematoma was correlated with decreased evacuation rate (0.76±0.21 vs. 0.85±0.2, p = 0.005), increased intracavitary bleeding score (3.03±1.44 vs. 2.39±1.22, p = 0.019), increased residual volume (14±13 vs. 7±12, p = 0.001), increased presence of amyloid (31% vs 17%, p = 0.034). Multivariate linear regression analysis of presence of cleft controlling for pre-operative hematoma volume predicted increased bleeding score by 0.56 (p = 0.026), and on separate analysis predicted decreased evacuation rate by 9% (p = 0.005). Multivariate ordinal regression analysis of presence of cleft controlling for pre-operative hematoma volume predicted increased probability of increased bleeding by 117% (OR 2.17, CI: 1.09 - 4.39, p = 0.029).

Conclusions: Preoperative hematoma heterogeneity, specifically presence of cleft, is associated with increased intracavitary bleeding, decreased evacuation rate and increased residual volume following MIS ICH evacuation. Understanding the impact of hematoma characteristics is integral for patient selection in MIS ICH evacuation and postoperative care planning.