Abstract WP342: Description of Pericavity Edema in Patients With Intracerebral Hemorrhage Who Have Undergone Endoscopic Minimally Invasive Evacuation

Introduction: Perihematomal edema (PHE) impacts outcome in spontaneous intracerebral hemorrhage (ICH) and has been well defined. As minimally invasive evacuation methods are formally evaluated, the degree of edema following evacuation may differ from PHE in measurement and time course characteristics. Here we define pericavity edema (PCE) as a new entity and formally evaluate its measurement with a semi-automated threshold-guided technique. Methods: Patients (n=46) with a primary supratentorial ICH who underwent endoscopic evacuation were included in this study. AnalyzePro software was used to perform semi-automated threshold-guided volume assessment on pre and post evacuation noncontrast head CTs of the hematoma, PHE, the cavity, PCE, and pneumocephalus if present. Two raters analyzed each subject, the first twice, and intraclass correlation coefficient (ICC) values were determined to assess the inter-rater reliability. Statistical analysis was performed on the mean results to determine the change in hematoma volume, edema, cavity size, and degree of pneumocephalus. Results: ICC values for all variables were greater than 0.75, indicating good to excellent reliability. The median preoperative PHE was 18.21 cm3, while the postoperative edema was 16.2cm3. There was a mean 78.9% decrease in hematoma and a mean 76.4% increase in edema. In patients with a cavity present, the median size was 10.4cm3. Conclusions: In conclusion, PCE was successfully measured using AnalyzePro based on ICC. A mean increase in edema was shown following endoscopic evacuation, similar previous research revealing an increase in edema volume growth immediately following ICH. Further research will aim to define the time course of edema volume change following endoscopic evacuation.