Histopathological observations in the brains of children exposed to inhalational anesthetic agents: a retrospective autopsy-based study.

BACKGROUND: Numerous animal models have demonstrated neuronal damage resulting from anesthetic exposure in the developing brain. Studies have shown a relationship between anesthetic exposure and brain hypoxia, neurodegeneration and apoptosis. The relevance of data derived from controlled experimental studies to human neuropathology is a subject of debate. This study compares histopathological findings in post-mortem brain tissue specimens from children with and without exposure to inhalational anesthetic agents. METHODS: Autopsy reports were reviewed. Patients were divided into exposure and non-exposure groups defined as any procedure involving inhalational anesthetic agents. A retrospective chart review was performed collecting pathological findings of the brain. The autopsy results examined the presence of twelve different histopathological parameters reflecting morphologic changes in thirteen regions of interest in the central nervous system. RESULTS: Post-mortem neuropathological findings were analyzed. Thirteen different areas were focused upon and changes were categorized into twelve histopathological parameters. Gliosis, which was confirmed by immunohistochemical staining for glial fibrillary acidic protein, was more prevalent in the exposure group (N.=48) compared to the non-exposure group (N.=20) (P<0.05). CONCLUSION: The role of anesthetic neurotoxicity is not well understood. Numerous animal models have demonstrated neuronal apoptotic changes linked to anesthetic exposure, there is no tangible evidence supporting this relationship in humans. Our analysis demonstrates histopathological brain changes in children with anesthetic exposure not seen in the non-exposed group. Analysis was based on histopathological parameters representative of salient morphological findings of injury, which were encountered in anatomically divergent regions. Gliosis was the only statistically significant finding in post-mortem brain samples of patients who had received anesthetics.