Experience with a programmable valve shunt system.

OBJECT: The goal of this study was to clarify the efficacy of the Codman Hakim programmable valve. Clinical data obtained in 179 patients with hydrocephalus or other intracranial fluid-accumulating diseases were analyzed.

METHODS

Shunt placement operations were effective in 168 patients, approximately one half (50.6%) of whose devices required reprogramming of opening pressure postoperatively. This was a significantly larger number of shunts than the authors had thought would need reprogramming. Extremely narrowed ventricles observed on computerized tomography scans, as well as clinical symptoms related to inadequate or excessive cerebrospinal fluid drainage, improved in patients after shunt reprogramming. Shunt reprogramming frequently was necessary in patients with posthemorrhagic acute hydrocephalus; the programmable valve proved particularly beneficial for such patients. Subdural effusion and arachnoid cyst also proved to be good indications for use of the valve. Twelve patients (7%) suffered complications postoperatively. The most common complication was valve obstruction, which occurred in five patients, most of whom had brain tumors.

CONCLUSIONS

The programmable valve was beneficial for the treatment of hydrocephalus and other intracranial fluid-accumulating diseases. It is important to be careful in selecting patients for treatment with the programmable valve, because complications involving the valve seem more likely in brain tumor cases. The valve proved to be poorly resistant to magnetic fields; therefore, it is essential to confirm opening pressure after every magnetic resonance imaging examination. The authors recommend that an identification system for patients be developed so that medical personnel will be aware of the presence of the valve and the previous setting of opening pressure.