title: Comparison of ventricular drain location and infusion test in hydrocephalus.
abstract: OBJECTIVE
  Suspected cerebrospinal fluid shunt (CSF) dysfunction in hydrocephalic patients poses a diagnostic uncertainty. The clinical picture can be non-specific and CT imaging alone is not always pathognomonic. Infusion tests are an increasingly used investigation for real-time hydrodynamic assessment of shunt patency. We report the correlation between infusion test results with the quality of ventricular drain placement on CT scans in a large retrospective group of hydrocephalic patients.
  
  
  METHODS
  Three hundred and six infusion test results performed in 200 patients were correlated with 306 corresponding CT head scans. Nominal logistic regression was used to correlate shunt catheter position on CT imaging to patency of ventricular drain as determined by infusion tests.
  
  
  RESULTS
  Infusion test results of shunt patency are statistically congruent with the analysis of shunt catheter position on CT head scans. Catheter tips completely surrounded by either parenchyma or CSF on CT imaging are strongly associated with evidence of occlusion or patency from infusion tests, respectively (χ² = 51.68, P < 0.0001, n = 306 and χ² = 31.04, P < 0.0001, n = 306).
  
  
  CONCLUSIONS
  The most important anatomical factor for shunt patency is the catheter tip being completely surrounded by CSF. Infusion tests provide functional and reliable assessment of shunt patency in vivo and are strongly correlated with the position of the ventricular catheter on CT imaging.
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: R
authors.initials: R
authors.lastname: Sinha
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: J A D
authors.initials: JA
authors.lastname: Morgan
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: J R
authors.initials: JR
authors.lastname: Wawrzynski
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: Z
authors.initials: Z
authors.lastname: Czosnyka
authors.affiliation: Department of Biomedical Engineering, Wroclaw University of Technology, Wroclaw, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Kasprowicz
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: M
authors.initials: M
authors.lastname: Czosnyka
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: M
authors.initials: M
authors.lastname: Garnett
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: P J A
authors.initials: PJ
authors.lastname: Hutchinson
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: J D
authors.initials: JD
authors.lastname: Pickard
authors.affiliation: Academic Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, England.
authors.forename: S J
authors.initials: SJ
authors.lastname: Price
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects / Q000592:standards*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging / Q000601:surgery; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013129:Spinal Puncture / Q000592:standards*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: hydrocephalus; infusion tests; ventriculoperitoneal shunts