Determining the best cerebrospinal fluid shunt valve design: the pediatric valve design trial

Myriad cerebrospinal fluid shunt valve designs are available (17, IS). None has ever been shown to be superior to another, although claims by neurosurgeons and shunt manufacturers of the merits of particular designs are numerous. Such is the case with two recent shunt valve designs, the Orbis-Sigma valve (Cordis Corporation, Miami, FL) and the Delta valve (PS Medical, Gofetta, CA). Both reduce the siphoning effect when the patient is in the upright position by different mechanisms. Reports of reduced complication rates in uncontrolled series have been attributed to diminished shunt overdrainage (13, 19, 20, 22).