Utility of radiography in suspected ventricular shunt malfunction

It is common to evaluate pediatric patients with suspected malfunction of intraventricular shunts (VS) with cranial computed tomography (CT) as well as radiographs. Yet, the clinical yield of these studies is not well defined. We conducted a study to determine if radiographs of VS add useful clinical data in the evaluation of shunt malfunctions. A retrospective chart review of children evaluated in the emergency department for potential VS malfunction was conducted. CT scan results were categorized into five distinct categories based on the presence of shunt malfunction and comparison to prior studies. Determination of the presence of VS malfunction was based upon the discharge diagnosis. There were 205 patient encounters identified. The mean age was 5.3 years. Forty-four of the visits involved children younger than 2 years of age. Forty-eight children (23% of total) were taken to surgery for shunt malfunction. Only 8 had radiography demonstrating breakage or discontinuity of the shunt or tubing. Of these, 6 had CT scans demonstrating increased intracranial pressure. The remaining 2 had vomiting and lethargy, with one also having evidence of cerebrospinal fluid extravasation on examination. Overall, CT scans identified 46 of 48 (96%) patients with malfunction of their VS. The 2 remaining children had radiographs demonstrating abnormality of their VS. Both children, however, had a classic clinical presentation of shunt malfunction. In this series, plain radiography in patients with suspected shunt malfunction, looking for breakage or discontinuity of the shunt, may represent unnecessary ionizing radiation exposure and expense.