Ventricular shunt tap as a predictor of proximal shunt malfunction in children: a prospective study

Brandon G. RocqueDepartment of Neurological Surgery, University of Wisconsin–Madison, Wisconsin

Search for other papers by Brandon G. Rocque in
jns
Google Scholar
PubMed
Close
 M.D.
,
Samir LapsiwalaDepartment of Neurological Surgery, University of Wisconsin–Madison, Wisconsin

Search for other papers by Samir Lapsiwala in
jns
Google Scholar
PubMed
Close
 M.D.
, and
Bermans J. IskandarDepartment of Neurological Surgery, University of Wisconsin–Madison, Wisconsin

Search for other papers by Bermans J. Iskandar in
jns
Google Scholar
PubMed
Close
 M.D.
Restricted access

Purchase Now

USD  $45.00

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $525.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $624.00
USD  $45.00
USD  $525.00
USD  $624.00
Print or Print + Online Sign in

Object

The clinical diagnosis of cerebrospinal fluid (CSF) shunt malfunction can be challenging. In this prospective study, the authors evaluated a common method of interrogating shunts: the shunt tap; specifically, its ability to predict proximal malfunction.

Methods

The authors performed standardized shunt taps in a consecutive series of cases involving children with suspected or proven shunt malfunction, assessing flow and, when possible, opening pressure. Data were collected prospectively, and results analyzed in light of surgical findings.

Results

A shunt tap was performed prior to 68 operative explorations in 51 patients. Of the 68 taps, 28 yielded poor or no CSF flow on aspiration. After 26 of these 28 procedures, proximal catheter obstruction was identified. After 28 taps with good CSF return and normal or low opening pressure, 18 shunts were found to have a proximal obstruction, 8 had no obstruction, and 2 had a distal obstruction. Another 12 taps with good CSF flow had high opening pressure; subsequent surgery showed distal obstruction in 11 of the shunts, and proximal obstruction in 1. The positive predictive value of poor flow was 93%, while good flow on shunt tap predicted adequate proximal catheter function in only 55% of cases.

Conclusions

Poor flow of CSF on shunt tap is highly predictive of obstruction of the proximal catheter. Because not all patients with good flow on shunt tap underwent surgical shunt exploration, the specificity of this test cannot be determined. Nonetheless, a shunt tap that reveals good flow with a normal opening pressure can be misleading, and management of such cases should be based on clinical judgment.

Abbreviations used in this paper:

CSF = cerebrospinal fluid; CT = computed tomography; MR = magnetic resonance.
  • Collapse
  • Expand
  • 1

    Duncan CC: Management of proximal shunt obstruction. Technical note. J Neurosurg 68:817819, 1988

  • 2

    Iskandar BJ, , McLaughlin C, , Mapstone TB, , Grabb PA, & Oakes WJ: Pitfalls in the diagnosis of ventricular shunt dysfunction: radiology reports and ventricular size. Pediatrics 101:10311036, 1998

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3

    Kestle J, , Drake J, , Milner R, , Sainte-Rose C, , Cinalli G, & Boop F, et al.: Long-term follow-up data from the Shunt Design Trial. Pediatr Neurosurg 33:230236, 2000

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4

    Sainte-Rose C, , Piatt JH, , Renier D, , Pierre-Kahn A, , Hirsch JF, & Hoffman HJ, et al.: Mechanical complications in shunts. Pediatr Neurosurg 17:29, 1991

  • 5

    Sekhar LN, , Moossy J, & Guthkelch AN: Malfunctioning ventriculoperitoneal shunts. Clinical and pathological features. J Neurosurg 56:411416, 1982

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6

    Sood S, , Canady AI, & Ham SD: Evaluation of shunt malfunction using shunt site reservoir. Pediatr Neurosurg 32:180186, 2000

  • 7

    Sood S, , Kim S, , Ham SD, , Canady AI, & Greninger N: Useful components of the shunt tap test for evaluation of shunt malfunction. Childs Nerv Syst 9:157162, 1993

    • Search Google Scholar
    • Export Citation
  • 8

    Winston KR, , Lopez JA, & Freeman J: CSF shunt failure with stable normal ventricular size. Pediatr Neurosurg 42:151155, 2006

  • 9

    Zorc JJ, , Krugman SD, , Ogborn J, & Benson J: Radiographic evaluation for suspected cerebrospinal fluid shunt obstruction. Pediatr Emerg Care 18:337340, 2002

    • Crossref
    • Search Google Scholar
    • Export Citation

Metrics

All Time Past Year Past 30 Days
Abstract Views 1336 416 66
Full Text Views 207 27 3
PDF Downloads 163 32 3
EPUB Downloads 0 0 0