Programmable valve breakage in shunt systems of children with posthemorrhagic hydrocephalus after minor head trauma-a case series.

Purpose: We report five rare cases of programmable valve breakage (Codman Hakim-Medos valve) in shunt systems of children with posthemorrhagic hydrocephalus. Only four similar studies have been published in the current literature.

Methods: Between 2013 and 2018, five children with posthemorrhagic hydrocephalus were admitted to the pediatric department. All patients had a history of slight blows to the head in a minor trauma and follow up MRI scans. After initial clinical examination, cranial computed tomography (CT) and X-ray were conducted.

Results: In all cases, pumping the reservoir resulted in very slow refilling. The cranial CT in one patient showed slit ventricles confirming the suspicion of overdrainage, the other cases a slight enhancement of the hydrocephalus. In lateral X-rays of the skull in comparison to the first X-ray control of the shunt valve, the pressure control chamber could be seen dislocated in the inferior part of the reservoir in all cases. Surgery revealed that the shunt valve was broken. The pressure control chamber had dropped to the bottom of the reservoir. After implantation of a new shunt valve, the symptoms resolved completely in all five children. Overall this complication occurred in 4.3% (5 of 85 implanted Codman Hakim-Medos valve) of all children necessitating ventriculoperitoneal shunt implantation between January 2013 and December 2018.

Conclusion: The well-accepted Codman Hakim-Medos programmable valve is part of a tube-system, which is designed to offer the possibility of a reliable and precise treatment of hydrocephalus. Various mechanical and non-mechanical complications of shunt systems have been reported. Valve breakage is a very rare condition, often missed, and must be kept in mind when trauma and prior MRI scan are reported.