Morphological findings of postshunt slit-ventricle in experimental canine hydrocephalus. Aspects of causative factors of isolated ventricles and slit-ventricle syndrome.

The progressive status of slit-ventricle and its associated pathology may be severe, occasionally resulting in the slit-ventricle syndrome or irreversible morphological changes in the brain and CSF pathways. To analyze the morphological changes of slit-ventricles critically, comparing the human form with canine hydrocephalus, 19 dogs had kaolin injected into the cisterna magna to produce hydrocephalus. The model of slit-ventricle was created by a low pressure arrangement (external ventricular drainage with extreme siphon effect). The gross morphological appearance showed thickening of the white matter, enlarged cortical vessels, and slit-ventricles. The brain parenchyma changes were observed as disorganized, with partially stripped-off ependymal lining, remarkable gliotic scar tissue in the subependymal areas and adjacent white matter, and widely opened Virchow-Robin spaces. These seem to be responsible for the decreased intracranial compliance and isolation of the CSF pathways.