title: Obstruction of a Codman-Hakim programmable valve by a migrating pressure control cam.
abstract: Although the Codman-Hakim programmable valve is popular, several problems arising from its design have been described. The authors report an additional cause of shunt obstruction in the system. A 6-year-old girl who had received a ventriculoperitoneal shunt with the Codman-Hakim programmable valve system presented with worsening consciousness. The valve proved hard to flush, and emergency revision of the valve was performed. Examination of the extracted valve revealed that the pressure control cam had migrated into the outlet of the valve, thus causing the obstruction. A crack in the plastic housing surrounding the cam suggesting a past impact to the system was also revealed. These factors should thus be kept in mind as potential sources of obstruction of the valve system, especially in patients susceptible to episodes of head impact.
authors.affiliation: Department of Neurosurgery, Kitasato University School of Medicine, Kanagawa, Japan. Satoru4756@aol.com
authors.forename: Satoru
authors.initials: S
authors.lastname: Shimizu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Utsuki
authors.forename: Sachio
authors.initials: S
authors.lastname: Suzuki
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Oka
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fujii
mesh_terms: D002648:Child; D003243:Consciousness; D006259:Craniocerebral Trauma; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005548:Foreign-Body Migration; D006801:Humans; D010969:Plastics; D011312:Pressure; D017287:Ventriculoperitoneal Shunt / Q000009:adverse effects*
chemical_list: D010969:Plastics