A study by the Hydrocephalus Clinical Research Network (HCRN) used data from 3 previous trials to determine the optimal position of ventricular catheter tips in ventriculoperitoneal shunts. Positioning of ventricular catheter tips were defined with 5 parameters: tip location (frontal horn, trigone, etc.); tip environment (surrounded by CSF, against ventricular wall, etc.); relationship to choroid plexus; ventricular placement of catheter holes; and crossing midline. First, 121 scans from an HCRN study on ventricular catheter insertion were reviewed to determine inter-observer agreement of the above five position parameters. Kappa values were >0.60 for all measurements except relationship to the choroid plexus (not used in analysis). Univariate analysis of tip positioning was performed and showed that tip location in the frontal horn is significantly associated with improved shunt survival (p=0.0015). However, in a multivariate model including tip position along with other variables known or suspected to affect shunt failure (patient age, etiology of hydrocephalus, decade of surgery, and entry site), only age and entry site were independently associated with shunt survival (Lower risk of shunt failure for anterior entry: OR 0.65 95% CI 0.51-0.83). These data show improved survival of anteriorly placed shunts, but suggest no relationship between tip position and shunt failure. To generate more robust evidence, a randomized controlled trial of catheter entry site is underway.
Journal of Neurosurgery