External dislocation of the metallic device of a shunt valve, an unusual long-term complication of the Holter valve--case report.

The case of a 20-year-old male with a mechanical disruption of a shunt valve in which proximal metal portion of the Holter valve was dislocated out of silicone casing is reported. In the three cases previously reported by Zander and Campiche (1980), mechanical traction force exerted on the two metallic extremities of the Holter valve incrusted on the growing skull was incriminated as the causative mechanism. In the present case, growth-related mechanical traction force was exerted on the extended portion of the shunt system. This suggests that the shunt valve of this type can be a locus minoris to long-standing mild mechanical traction force exerted on the extended portion of the shunt system.