Early and effective intracerebral hemorrhage evacuation is associated with a lower 1-year residual cavity volume and better functional outcomes

Background We explored the clinical significance of the residual hematoma cavity 1year after minimally invasive intracerebral hemorrhage (ICH) evacuation. Methods Patients presenting with spontaneous supratentorial ICH were evaluated for minimally invasive surgical evacuation. Inclusion criteria included age >= 18 years, preoperative hematoma volume (Hv) >= 15mL, presenting National Institutes of Health Stroke Scale score >= 6, and premorbid modified Rankin Scale (mRS) score <= 3. Patients with longitudinal CT scans at least 3 months after evacuation were included in the study. Remnant cavity volumes (Cv) after evacuation were computed using semi-automatic volumetric segmentation software. Relative cavity volume (rCv) was defined as the ratio of the preoperative Hv to the remnant Cv. Results 108 patients with a total of 484 head CT scans were included in the study. The median postoperative Cv was 2.4(IQR 0.0-11) mL, or just 6% (0-33%) of the preoperative Hv. The median residual Cv on the final head CT scan a median of 13 months (range 11-27 months) after surgery had increased to 9.4(IQR 3.1-18) mL, or 25% (10-60%) of the preoperative Hv. rCv on the final head CT scan was negatively associated with measures of operative success including evacuation percentage, postoperative Hv <= 15mL, and decreased time from ictus to evacuation. rCv on the final head CT scan was also associated with a worse 6-month functional outcome (beta per mRS point 17.6%, P<0.0001; area under the receiver operating characteristic curve 0.91). Conclusion After minimally invasive ICH evacuation the hematoma lesion decompresses significantly, with a residual Cv just 6% of the original lesion, but then gradually increases in size over time. Early and high percentage ICH evacuation may reduce the remnant Cv over time which, in turn, is associated with improved functional outcomes.