Prosepective Study to Evaluate Rate and Frequency of Perturbations of Implanted Programmable Hakim Codman® Valve after 1,5-Tesla MRI

Background Exposure to magnetic fields may alter the settings of programmable ventriculo-peritoneal shunt valves or even cause permanent damages to these devices. There are little information about this topic, none on live patients. Objective To investigate the effects of 1,5-Tesla MRI on Hakim-Codman® (HC® ) pressure-programmable valves implanted in our hospital. Methods A single-center prospective study to assess the rate of perturbations of HC® programmable valve implanted. One-hundred consecutive patients implanted for different clinical reasons between 2008 and 2012 were examined. A conventional skull x-ray before and after a Standard MRI on 1,5 Tesla (T). We face pre and post results, analyze modification rate and verify eventual damages to the implanted devices. Results Implanted HC® valves are extremely handy and durable even if they are likely to change often due to the exposure to magnetic fields. None of the patients complains of heating effects. Oscillations range from 10 to 30 mmH2 0 with a case that reached 50 mmH2 0 and one that reached 60mmH2 0. Global alteration rate was 40%; 10 patients (10%) experienced a 10mmH20 changes; 14 patients (14%) 20mmH20; 6 patients (6%); 30mmH20; 8 patients (8%) 40mmH20, 1 patient 50mmH20 and 1 patient 60 mmH20. Conclusions HC® valves presented a variable perturbation rate with an alteration rate of 40% by 1,5-T MRI. We haven’t observed malfunctioning hardware after magnetic influnce. We claim a cranial x-ray immediately afetr MRI because of a high risk (40%) of decalibration especially in patients with low ventricles compliance.