[Spontaneous rotation of programmable pressure valve in the chest wall: report of 3 cases]

Using a Sophy-valve system, complications after V-P shunt have been encountered in 3 cases. Turning over of the valve in a subcutaneous pocket would lead to a false judgement of setting pressure, and to serious iatrogenic complications. The valve seems to turn over only in the condition of subcutaneous placement in the chest. Probable causes are loose chest tissue, difficulty of tight fixation, and round and smooth shape of the valve. It should be kept in mind that the Sophy-valve can spontaneously turn over when it is placed in the chest. Careful examination of the chest X-ray can help to judge whether the valve is in appropriate position or not.