External ventricular drainage or ventriculostomy is a common neurosurgical technique and accurate placement of the ventricular catheter is one of the most important variables in the longevity of shunt survival 1) 2).
Cerebrospinal fluid (CSF) external drainage devices are used to drain CSF and to monitor the flow of CSF from the ventricular system in order (1) to control intracranial pressure (ICP), (2) to evaluate CSF chemistry and cytology, and (3) to provide temporary egress for CSF in patients with infected or malfunctioning cerebrospinal fluid shunts.
The optimal setting for EVD placement in regards to safety and accuracy of placement is poorly defined.
After days of use, a decision is made to remove the EVD or replace it with a shunt, involving EVD weaning and CT imaging to observe ventricular size and clinical status. This practice may lead to prolonged hospital stay, extra radiation exposure, and neurological insult due to ICP elevation.
Ventriculostomy entry sites are commonly selected by freehand estimation of Kocher's point or approximations from skull landmarks and a trajectory toward the ipsilateral frontal horn of the lateral ventricles.
Tunneled external ventricular drainage.
Standard external ventricular drainage.
A study design of a single center, prospective, randomized controlled trial to investigate whether guided ventriculostomy is superior to the standard freehand technique. One strength of this study is the prospective, randomized, interventional type of study testing a new easy-to-handle guided versus freehand ventricular catheter placement. A second strength of this study is that the power calculation is based on catheter accuracy using an available grading system for catheter tip location, and is calculated with the use of recent study results of our own population, supported by data from prominent studies 3).