The utility of the plain radiograph "shunt series" in the evaluation of suspected ventriculoperitoneal shunt failure in pediatric patients

Abstract

Background: To our knowledge, the sensitivity of plain radiography, known as the shunt series, in diagnosing an etiology of ventriculoperitoneal (VP) shunt malfunction in children has not been previously investigated.

Objective: To determine the accuracy of plain radiography in diagnosing VP shunt failure in children in whom shunt malfunction is clinically suspected.

Materials and methods: We retrospectively reviewed the charts of 238 children who had undergone plain radiographic examination for evaluation of clinically suspected VP shunt failure over a 5-year period. The results were compared with those of CT, MRI, and nuclear cisternography.

Results: Just 6.72% of patients demonstrated plain radiographic signs of shunt failure. Of patients with normal plain radiographs, 43% demonstrated shunt abnormalities on CT, MRI or cisternography. Statistical analysis indicated that no more than 10.46% (P < 0.05) of plain radiographs showed signs of failure and that the sensitivity of plain radiography for the detection of VP shunt failure is no higher than 31%. Furthermore, there was poor agreement between the results of plain radiography and those of CT, MRI and cisternography.

Conclusion: Children with clinically suspected VP shunt failure should proceed directly to cross-sectional or nuclear imaging, as plain radiographic examinations have low sensitivity and significant false-negative rates for detecting shunt abnormalities in all-comers. Use of the shunt series should be limited to patients who specifically have suspected mechanical causes of shunt failure.