CODMAN-MEDOS PROGRAMMABLE SHUNTS - RESULT S IN 53 IMPLANTS IN 50 PATIENTS

Fifty three Codman Medos programmable valves were implanted in 50 pati ents (28 men and 22 women) aged 5 to 77 years, from April 1992 to Febr uary 1994. They presented with a hydrocephalus 43 times, an arachnoid cyst three times and a CSF leakage four times. The aims of this study were: a) to test the reliability of this equipment, in current use as well as its eventual advantages, inconveniences and restraints, b) to determine its best indications. Follow-up ranged from 12 to 36 months (average = 22 months). Five patients were lost for follow-up. One pati ent died from a post-operative sepsis. Four died from their disease. I nfectious complications concerned 6 patients (11 %). A radio-clinical overdrainage syndrome appeared in 9 patients with slit-ventricles, 5 o f them associated with sub-dural collections. All these cases were tre ated with shunt reprogrammings. While 43 pressure settings over 53 wer e satisfactory in the immediate post-operative period, it appeared tha t only 38 % of shunts had required one only setting when the study per iod was over. A certain number of pressure adjustments malfunctioned: 6 times, post-operative X-ray controls showed pressures significantly different from the figures which had been selected (difference from - 30 mm H2O to + 70 mm H2O); pressure readjustments were effective and a ccurate for five of them, but one shunt had to be changed; 15 deprogra mmings were detected during long term follow-up, 9 of them after MRI. Pressure programming was readjusted only on patients presenting with c linical signs, i-e mainly for those having a pressure difference > +/- 30 mm H2O. As a conclusion, the authors consider that such a shunt ca n be very useful in some precise indications as. NPH, multioperated hy drocephalus, arachnoid and porencephalic cysts, some spontaneous or ia trogenic CSF leakages, temporary shunts necessitating a progressive wi thdrawal. Because of a) the cost of this equipment, b) the specific re straints (X-rays controls, programmer), and c) the specific incidents (spontaneous and/or post-MRI deprogramming), it seems difficult to gen eralize indications to all cases of hydrocephalus. On the other hand, these shunts have the great advantage of simplifying the treatment of overdrainage by avoiding, in all cases, a reoperation for changing the shunt and/or removing a subdural hematoma. Consequent economies due t o a significant diminution of the duration of hospitalisation, could j ustify an enlargment of indications.