Comparative Study with Flow Regulated Valve and Differential Pressure Valve in Ventriculo-Peritoneal Shunt

ABSTRACT

In the management of hydrocephalus by shunts, two valve types are currently available:1) differential pressure valves(DPV) which provide a constant resistance and allow CSF flow when the proximal hydrostatic pressure exceeds the valve's present closing pressure, and 2) the newer variable resistance flow regulated valve(FRV). Eighty one cases of hydrocephalus were reviewed in this study to compare the two devices. Forty two patients were operated with FRV and 39 patients were operated with DPV. This study compared the preoperative and postoperative KPS score, ventricular size, periventricular low densities, and the frequency of complications. We have conclude that 1) In group 1(KPS score 50-70), FRV is useful and in group 2(KPS score 20-40), DPV is useful, 2) FRV is useful in dealing with excessively reduced ICP caused by over-drainage of a ventricular shunt;it can prevent postshunt subdural hygroma and symptomatic slit ventricles. 3) For evaluation of the effectiveness of FRV, the decrease of periventricular low densities is a more valuable index than the change of ventricle size(Hydrocephalus index).