Are variations in ventricular catheter placement related to design of the catheter? A single-center cohort study.

Background: The use of intracranial catheters is a common procedure used for neurosurgical patients with a variety of pathologies. Despite its frequency of use, shunt failure and revision have been reported to be a common problem. Given that depth of insertion can significantly affect the catheter tip position, a single institution retrospective chart review was performed to examine the accuracy of shunt and external ventricular drain (EVD) placement.

Methods: Computed tomography (CT) images of the head following shunt or ventriculostomy insertion were analyzed to determine the delta between the final length of the intracranial catheter and the intended depth described in the operative notes.

Results: We found that there was a statistically significant difference in the accuracy of placement when comparing EVDs to shunts. The most used EVDs at our institution are marked with a solid black line in increments spaced 2 cm apart. The most used ventricular shunt catheter has a marking at 5 cm and 10 cm from the tip of the catheter. We believe that the visual confirmation that is afforded by metric unit markings on the EVD allows for better final placement of the catheter at the outer table of the calvarium.

Conclusion: The addition of regular millimeter metric unit markings by the manufacturer is imperative in decreasing the chances of error in the insertion of ventricular catheters and preventing potential neurovascular injury to the surrounding structures.