The programmable shunt-system Codman Medos Hakim: A clinical observation study and review of literature

Hydrocephalus can be defined as clinically symptomatic dilatation of the internal ventricular system at the expense of brain and blood volume. Shunt insertion is the mainstay of therapy for communicating hydrocephalus. One of the most frequently used valves is the programmable Codman Medos Hakim valve which enables the pressure level to be adjusted from 30 to 200 mmH2O. The problem of functional over- or underdrainage and the associated complications should be significantly reduced if not excluded. Especially in the clinical application of the Codman Medos Hakim Shunt System in hydrocephalus of other etiology only a few studies can be found. This study aims to increase knowledge of both the safety of Codman Medos valves with SiphonGuard in the clinical application as well as the correct choice of the pressure level for different indications.

In this retrospective study, 101 patients were included who underwent surgery with the adjustable "Codman Medos Hakim" valve with "SiphonGuard" between January 2010 and July 2013. We analyzed the patient files and imaging (CCT, cMRT) data. The statistical examinations were performed using the WINStat program for Excel.

Our results show that an initial pressure level of 120mmH2O proved to be suitable in all subgroups. After optimization of the initial pressure level 70.3% of the valves (71 valves) had a pressure level of 120mmH2O. Importantly, only in the SAH subgroup the clinical improvement was correlated with a reduction in the measured indices. But in all subgroups a clinical deterioration was associated with an increased ventricular size.

Overall, the clinical data show that an initial pressure level of 120mmH2O seems to be appropriate for most patients treated in this series. Measured indices from the cranial imaging can provide valuable indications for the presence of a suboptimal valve setting for the individual patient.