The necessity of shunt series

J Neurosurg Pediatr. 2010 Nov;6(5):468-73. doi: 10.3171/2010.8.PEDS09557.

Abstract

Object: This work assessed the value of shunt series in the evaluation of children with CSF shunts, a test that is frequently ordered as part of the assessment of shunt integrity.

Methods: The medical records of all children who underwent shunt series at Children's Hospital of Eastern Ontario between 1975 and 2007 were reviewed. Ancillary studies that were performed within 2 days of the shunt series (brain CT, MR imaging, ultrasonography, and radionuclide shuntography) were noted, as well as the subsequent requirement for a shunt revision. Shunt series and ancillary studies were categorized as either positive (revealing an observable sign that a shunt-related problem was present, such as shunt discontinuity on the shunt series or enlargement of the ventricles on the brain CT scan) or negative (no clear sign of a shunt-related problem). Shunt series were further grouped into shunt series performed for diagnostic reasons, shunt series performed on a routine basis during follow-up in clinic, and shunt series performed postoperatively. The length of time between shunt insertion and shunt fracture was noted. Statistical analyses were performed, including the derivation of sensitivities and specificities.

Results: There were 3416 shunt series in 394 patients, of which 3004 were performed with ancillary studies. On average, patients underwent 9 shunt series, with a minimum of 1 and a maximum of 43, during the follow-up period (range 3 weeks to 19 years). A total of 2493 shunt series and ancillary studies (83%) yielded negative results and no surgery was performed. One hundred thirty shunts series were negative with a positive ancillary study (4.3%) and no surgery was required. In 8.7% (261 shunt series negative, ancillary studies positive) shunt revision surgery was necessary. The opposite trend was far less prevalent (17 shunt series positive, ancillary test negative; 0.6%) in which surgery was required. There were 87 patients with 96 shunt fractures (2.8% of shunt series). The average time between shunt insertion and shunt fracture was 7.9 years (range 3 months to 18 years). Shunt series had a sensitivity of 18% and a specificity of 97%. The ancillary studies had a sensitivity of 84% and a specificity of 85%.

Conclusions: The routine utilization of shunt series in the evaluation of a child with a CSF shunt is not necessary. This study showed that a very small number (0.6%) of shunt series helped in surgical decision making. Shunt series can be performed in selected cases, especially preoperatively in the absence of a baseline study to obtain information necessary for surgical planning.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Cerebrospinal Fluid Shunts / adverse effects*
  • Cerebrospinal Fluid Shunts / instrumentation*
  • Child
  • Child, Preschool
  • Device Removal
  • Diagnostic Imaging
  • Equipment Failure*
  • Female
  • Follow-Up Studies
  • Humans
  • Hydrocephalus / diagnosis
  • Hydrocephalus / surgery*
  • Infant
  • Infant, Newborn
  • Male
  • Postoperative Complications / diagnosis*
  • Postoperative Complications / surgery
  • Reoperation
  • Retrospective Studies
  • Sensitivity and Specificity
  • Young Adult