Utilization and cost effectiveness review of shunt series to rule out ventriculoperitoneal shunt malfunction

Abstract

Purpose: To evaluate the usefulness of the conventional radiographic shunt series in the initial work-up of patients suspected of having ventriculoperitoneal shunt malfunction, and to describe an imaging work-up algorithm. Methods: Charts of 33 patients with shunt series were retrieved from medical records and reviewed. Twelve patients were excluded either because there was no head CT scan done at the time of the shunt series or because the studies were done immediately postoperatively. The remaining 21 patients had a total of 67 shunt series and head CT scans performed to rule out shunt malfunction. Patients' age range was 8 months to 81 years. There were 9 female and 12 male patients. Only three patients were more than 17 years old. Results: In 12/67 cases (18 %) the CT demonstrated normal-size ventricles. In none of these cases did the patients undergo shunt revision. Of the cases where there was an abnormal CT result, 22/67 (33 %) showed increasing hydrocephalus, 5 (7 %) showed enlarged ventricles with no comparison study, and 28 (42 %) showed stable enlarged ventricles. The shunt was revised in 22/67 (33 %) cases. No shunt series was interpreted as demonstrating abnormality of the shunt. Conclusion: Routine shunt series should not be the initial imaging study in the work-up of patients who present to rule out shunt malfunction. They may be helpful following CT and neurosurgical evaluation of those patients who are scheduled to undergo operative shunt revision.