1889. Cerebral microdialysis as a marker of perihematomal edema in spontaneous and traumatic intracranial hemorrhages

Authors: Diem Kieu Thi Tran, MD; Jordan Xu, MD; Ishan Shah; Peter Tran; Jefferson Chen, MD, PhD (Irvine, CA)

Introduction: Spontaneous intracerebral hemorrhages(sICH) and traumatic intracerebral hemorrhages(tICH) are major clinical challenges in the intensive care unit. Untreated, secondary injury can result in neuronal cell death, cerebral edema(CE), and global increased intracranial pressure(ICP). Recent clinical trials have questioned the efficacy of surgical intervention. There has been recent evidence that the hemorrhage itself augments the local inflammatory response and ensuing cerebral edema. ICPmonitors provide information about the global effects of the ICH. Multimodal brain monitors(MMM) offer additional insights into the effects of these hemorrhages on the surrounding milleau. In particular, cerebral microdialysis(CMD) provides information about the metabolic state of the tissue surrounding the hemorrhage. Methods: A retrospective analysis of 5 patients with sICH(4) or tICH(1) who were implanted with multimodal brain monitors (microdialysis(MD), ICP, cerebral blood flow(CBF), brain oxygenation) prior to surgical removal of the hemorrhage using minimally invasive parafascicular surgery(MIPS) was conducted. Lactate/Pyruvate was measured via CMD prior to and at least 48 hours after intervention. Student’s t-test were performed to compare CMD data before and after hemorrhage removal. Results: There were four sICH and one tICH patient included in this study. CT scans demonstrated that the MMM were in the perihematoma zone. In all of these patients, lactate/pyruvate were clearly abnormal immediately prior to and immediately after intervention. This significantly decreased to normal levels within 24 hours of intervention(p<0.005). Changes in ICP, brain oxygenation, and CBF did not demonstrate the same statistically significant changes. Conclusion: Multimodal brain monitoring and particularly CMD may provide useful information about the perihematoma CE. This is the first demonstration of the statistically significant improvement of the cerebral metabolism(lactate/pyruvate) in this region with the removal of the ICH via MIPS. This supports the belief that removal of the hemorrhage may improve the metabolic environment of the perihematoma zone.