gms | German Medical Science

Objective: Malfunction in ventriculoperitoneal shunts is common and may due to infection, catheter displacement, abdominal pseudocyst formation, catheter-discontinuity, -kinking, or -occlusion. To investigate the reason for shunt malfunction dynamic contrast enhanced shuntogram can be a useful additional procedure offering extended diagnostic value compared to plain radiographs. We retrospectively analysed contrast enhanced shuntograms in our institution for patients with symptoms of shunt malfunction regarding indication, technical performance, radiological evaluation and therapeutic consequence.

Method: 84 individual patients with different kinds of hydrocephalus who suffered from symptoms of shunt malfunction that could not be conclusively explained by basic diagnostic procedures received a total of 101 contrast enhanced shuntograms. The standardised shuntogram was performed via X-ray- guided punctures of the valve prechamber, the control reservoir or the shunt catheter itself. After aspiration of CSF contrast agent was administered to illustrate catheter filling and course to the point of regular intraperitoneal leakage. Diagnostic results constituted normal or pathological shuntogram and led to either surgical or conservative treatment.

Results: In all 101 cases the shuntogram was accomplished technically successful by neurosurgical-neuroradiological collaboration and was well tolerated from the patient side. One patient experienced symptoms of allergic reaction that responded promptly to prednisolone medication. In 57 of all cases (56%) shuntograms were interpreted as normal. In 51 of these cases (89%) shuntograms reliably excluded any mechanical reason for shunt malfunction and patients were treated conservatively, whereas in 6 cases the patient was brought to the operating theater for different shunt related problems including infection and exploration. Pathological shuntogram was constituted in 44 of all cases (44%) and had exposed a conclusive rational of shunt malfunction followed by targeted surgical VP-Shunt revision in 42 of these cases (95%).

Conclusions: Shuntograms should be carefully indicated and performed in a standardised procedure. Sufficient implementation requires detailed information about the particular shunt system and corresponding clinical findings. With a positive predictive value of 95% and negative predictive value of 89% in our series, shuntogram is a reliable diagnostic tool to detect cause of shunt malfunction.