Surgical treatment of posthemorrhagic infantile hydrocephalus.

The incidence of post-hemorrhagic hydrocephalus (PHH) remains stable over the time since the improvement in the perinatal assistance permits to reduce the risk of preterm brain hemorrhage and, at the same time, to increase the rate of surviving children potentially developing PHH. Children showing symptomatic ventriculomegaly (usually following Papile's grade III or IV hemorrhage) are candidate to treatment. Temporary treatment is based on medical therapy or on transient surgical manoeuvres (lumbar tapping, subcutaneous reservoir, external ventricular drainage, brain wash) with the goal of avoiding or to postponing the definitive surgical operation. Ventriculo-peritoneal shunt still represents the main surgical procedure for PHH. Especially in low-weight babies, however, this procedure is burdened by a high rate of complications as shunt infection or obstruction, skin erosion. PHH is actually one of the types of hydrocephalus more frequently requiring multiple operations (about 30% of the cases). The advent of neuroendoscopy reduced the risk of complications but did not affect the risk of reoperations significantly. Endoscopy is useful in treating the complications of the hemorrhage, for example by aspirating ventricular blood clots, by fenestrating intraventricular cysts or septa, or by treating isolated ventricles (septostomy, aqueductoplasty). These procedures allows the patient to avoid multiple shunts and, therefore, to reduce the risk of complications. However, endoscopic third ventriculostomy, which is the endoscopic definitive option for PHH, is effective in about one third of the cases, thus resulting in the need of reoperation. Immaturity of the CSF re-adsorption pathways, obstruction of the subarachnoid spaces and low intracranial pressure are the main causes of endoscopy failures.