Do adjustable shunt valves pressure our budget? A retrospective analysis of 541 implanted Codman Hakim programmable valves.

Based on a retrospective study in which a total of 541 Codman Hakim Programmable Valves (CHPV) were implanted in 477 patients over a 6-year period, this cost analysis was performed. By using a valve with an adjustable opening pressure, valve exchange to alter the opening pressure and surgical evacuation of subdural haematomas and hygromas can be avoided. Dividing the added cost for using the CHPV by the cost of implanting a non-programmable Hakim valve results in 105.8 valve exchanges, which would have had to be avoided to break even financially. On 107 occasions a valve was adjusted by a magnitude of 50 mmH2O or more. This, if an adjustment of that magnitude is said to correspond to a valve exchange, is sufficient to break even. The analysis suggests that the extra cost of the valve is outweighed by the ability to adjust the opening pressure setting non-invasively.