Confirmation of the initial pressure setting in Codman-Hakim programmable valves under magnification--technical note.

Codman-Hakim programmable valves allow neurosurgeons to adjust the opening pressure to the patient's particular clinical needs. However, the pressure control cam is extremely small, so identification of the pressure indicator and its operation is somewhat difficult when initially setting the opening pressure before implantation. We employed a commercial loupe on the program transmitter unit to sufficiently enlarge the view of the cam for clear identification. We recommend that the manufacturer to incorporate a loupe to provide a more sophisticated product.