Most children with spina bifida aperta have implanted CSF shunts. However, the efficacy of adding surveillance imaging to clinical evaluation during routine follow-up as a means to minimize the hazard of shunt failure has not been thoroughly studied.
A total of 396 clinic visits were made by patients with spina bifida aperta and shunt-treated hydrocephalus in a spina bifida specialty clinic during the calendar years 2008 and 2009 (initial clinic visit). All visits were preceded by a 6-month period during which no shunt evaluation of any kind was performed and were followed by a subsequent visit in the same clinic. At the initial clinic visit, 230 patients were evaluated by a neurosurgeon (clinical evaluation group), and 166 patients underwent previously scheduled surveillance CT scans in addition to clinical evaluation (surveillance imaging group). Subsequent unexpected events, defined as emergency department (ED) visits and caregiver-requested clinic visits, were reviewed. The time to an unexpected event and the likelihood of event occurrence in each of the 2 groups were compared using Cox proportional hazards survival analysis. The outcome and complications of shunt surgeries were also reviewed.
The clinical characteristics of the 2 groups were similar. In the clinical evaluation group, 2 patients underwent shunt revision based on clinical findings in the initial visit. In the subsequent follow-up period, there were 27 visits to the ED and 25 requested clinic visits that resulted in 12 shunt revisions. In the surveillance imaging group, 11 patients underwent shunt revision based on clinical and imaging findings in the initial visit. In the subsequent follow-up period, there were 15 visits to the ED and 9 requested clinic visits that resulted in 8 shunt revisions. Patients who underwent surveillance imaging on the day of initial clinic visit were less likely to have an unexpected event in the subsequent follow-up period (relative risk 0.579, p = 0.026). The likelihood of needing shunt revision and the morbidity of shunt malfunction was not significantly different between the 2 groups.
Surveillance imaging in children with spina bifida aperta and shunted hydrocephalus decreases the likelihood of ED visits and caregiver-requested clinic visits in the follow-up period, but based on this study, its effect on mortality and morbidity related to shunt malfunction was less clear.
Abbreviations used in this paper:ED = emergency department; EVD = external ventricular drain; LOS = length of stay.