Do CT Scans Following EVD Placement Meaningfully Change Clinical Care? A Two-Year Retrospective Analysis at Westchester Medical Center

Introduction: External ventricular drains (EVDs) are essential for relieving elevated intracranial pressure in patients with acute neurological deficits. Despite their widespread use, freehand EVD placement is sometimes suboptimal. At our institution, a CT scan is routinely obtained following EVD placement to assess accuracy and possible hemorrhage, though the clinical benefits of this practice remain uncertain.

Methods: This study retrospectively examined a level I trauma center database at Westchester Medical Center (WMC) between January 1st, 2021 and December 31st, 2022 and comprised 103 adult patients who underwent EVD placement. Accuracy of EVD placement was evaluated by the Kakarla et al. system.

Results: The mean patient age was 54.1 ± 17.1 years (age range, 18-86 years), and the most common indications for EVD placement were intraventricular hemorrhage (35.9%) and subarachnoid hemorrhage (35.9%). The average length of time an EVD was placed was 11.6 ± 10.0 days, and 20 patients had EVD tract hemorrhages (18.3%), although all but one of these were trace and therefore clinically insignificant. Among 109 post-EVD CT scans, 104 EVD tips (95.4%) in 99 patients were Grade I, while 3 EVD tips (2.8%) in 3 patients were Grade II, and 2 EVD tips (1.8%) were Grade III in 2 patients. In one patient, the EVD was revised twice following Grade II and Grade III nonfunctional placements, while in another patient the EVD was revised once after a Grade III nonfunctional placement. Two other patients did not undergo EVD revisions despite Grade II placement, as their drains were functional.

Conclusion : Emergency freehand placement of an EVD may lead to inaccurate placement, and when drains are nonfunctional, CT scans are indicated. However, routine CT scans did not change patient management when the EVDs were functional in our study, even if the placement was suboptimal.