Emergency department evaluation of ventricular shunt malfunction: is the shunt series really necessary?

The malfunction of a ventricular shunt is one of the most common clinical problems encountered in pediatric neurosurgery. Standard emergency department (ED) evaluation of suspected shunt malfunction consists of plain radiographs of the skull, neck, chest, and abdomen (shunt series) to look for mechanical breaks, kinks, and disconnections in the shunt, and a cranial computed tomography (CT) scan to evaluate for signs of increased ventricular size. We hypothesized, however, that in the context of a cranial CT scan that did not demonstrate a shunt malfunction, obtaining the shunt series would not prove to be clinically useful.

A retrospective chart review was conducted of all patients younger than 18 years with a history of a ventricular shunt who presented to an urban, tertiary pediatric ED between January 1, 2000, and September 30, 2004, for suspected shunt malfunction. Demographic and clinical characteristics of patients were recorded, as well as the results of shunt series and cranial CT scans. Shunt malfunction was defined as the performance of a shunt revision within 1 week of radiographic evaluation.

During the study period, 291 children with a ventricular shunt were evaluated in the ED 461 times for suspected shunt malfunction. The mean age of patients was 90.6 months (SD, 71.5 months); 163 (58.5%) were men, and 209 (71.8%) were white. Three hundred sixty patients (78.1%) had a shunt series performed during their ED evaluation, and 410 (88.9%) had a CT scan of the head. Seventy-one patients (15.4%) were diagnosed with shunt malfunction. Twenty-two had a normal cranial CT scan. Of these patients, 6 had an abnormal shunt series, and 14 had a normal shunt series.

The routine use of the shunt series seems warranted in the evaluation of the child with suspected shunt malfunction as children with shunt malfunction may present with a normal cranial CT scan but an abnormal shunt series.