External ventricular drains and risk of freehand placement: A systematic review and meta-analysis

External ventricular drains (EVDs) are used to monitor and treat elevated intracranial pressure. EVDs are often placed blindly without the use of imaging guidance, and successful placement with respect to pass attempts and final catheter location may suffer as a result of this freehand technique.

A systematic literature search was conducted in PubMed, Embase, Web of Science, and Cochrane databases to identify studies pertaining to freehand EVD placement through March 30, 2022. Studies were included if they reported percentage of EVDs placed successfully on the first pass attempt, or final catheter location as defined by the Kakarla Grading System. Pooled weighted incidence estimates and 95% confidence intervals (95%CI) were calculated using a random effects model.

Of the 2964 results returned from the literature search, 39 studies were included in this meta-analysis. These studies reported on 6313 EVDs placed via freehand technique in 6070 patients with the following respective incidence: successful EVD placement on the first attempt (78%, 95%CI: 67-86%); placement with a Kakarla Grade of 1 (optimal location) (72%, 95%CI: 66-77%); hemorrhage (7%, 95%CI: 6-10%), and infection (5%, 95%CI: 3-8%).

Only 78% of EVDs in this meta-analysis were placed successfully on the first pass, and only 72% of final placements were deemed optimal. This represents a relatively high rate of suboptimal outcomes with respect to EVD placement, which could potentially be avoided with the use of navigation-assisted placement techniques.