Clinical experience with a pressure-adjustable valve SOPHY in the management of hydrocephalus.

Seventy-four patients with hydrocephalus due to a variety of causes were treated with a cerebrospinal fluid (CSF) shunt, incorporating a recently developed pressure-adjustable valve SOPHY (PAVS). The PAVS may be changed percutaneously with the help of an externally applied magnet in order to select a high-, medium- or low-valve opening pressure, whenever the need for a change in pressure characteristics seems necessary to the neurosurgeon. The percutaneous pressure adjustment obviated up- or downgrading of a medium pressure position by surgical means in half of our patients during the follow-up time (up to 39 months; mean follow-up 16.7 months). In 66 patients (89%) decreased ventricle volume and improvement of the clinical sign of increased intracranial pressure were established. In 11 patients a valve or a catheter infection occurred; in 6 of these patients the valve had to be removed. Half of this group consisted of patients under 2 years of age. Significant technical complications related to the PAVS did not occur in our series but until a somewhat smaller PAVS is available, we cannot recommend its use in neonates or in small infants. In all other patients the PAVS is a very valuable instrument in the surgical management of hydrocephalus because it makes shunt revisions for inadequate valve pressure obsolete in individual patients.