Pediatric hydrocephalus: Pathophysiological concept and treatment

The evolution of the pathophysiological concept and the surgical treatment of pediatric hydrocephalus are reviewed in this article. From the era of the ancient Greeks to the 19th century, hydrocephalus has been recognized as the accumulation of cerebrospinal fluid (CSF) in the brain. In the 20th century, the major CSF pathway was elucidated as follows: the majority of CSF was produced from choroid plexuses, passing through the ventricles to the subarachnoid space, then absorbed from the arachnoid granules. The main pathophysiology of hydrocephalus was proposed as disorders of the major CSF pathway. The minor CSF pathway was proposed as CSF exchanges among transependymal, intraparenchymal, perivascular, and interstitial spaces. The concept of minor pathway hydrocephalus in infants was proposed as well as evolution theory in CSF dynamics. In addition, it appears that interstitial fluid and CSF are formed by water filtration from the walls of arterial capillaries, and absorbed from venous capillaries and postcapillary venules. Hydrocephalus had been treated by open- or closed-ventricular drainage until the 19th century. The third ventriculostomy and the choroid plexectomy were employed in the beginning of the 20th century, but declined in use because of poor results. In recent years, third ventriculostomy has become the first choice of treatment for non-communicating hydrocephalus, because of the technical advancements made utilizing neuroendoscopy. As for shunts, various attempts were made the before the 1960’s, but these were often complicated by infections or by thrombotic obstructions. Ventriculoperitoneal shunts have become the most popular since the 1960’s, and various shunt products have been made to reduce shunt malfunction.