Is Image Guidance Essential for External Ventricular Drain Insertion?

Abstract

This study aimed to compare the external ventricular drain (EVD) placement accuracy and complication rates, between neuronavigation-guided, ultrasound-guided, and freehand techniques in our single-center cohort, and through an additional meta-analysis of the currently available literature. A retrospective review of patients who underwent EVD insertion from January 2016 to April 2019 was conducted. Information regarding demographics, indication, Evans index, use of image guidance, accuracy of catheter tip placement, and procedural complications was extracted from electronic records and imaging systems. The accuracy of the EVD tip placement was classified according to the Kakarla grading system into optimal, or suboptimal based on its proximity to the Foramen of Monro and involvement of noneloquent/eloquent structures. In total, 294 patients (median age of 54 years) underwent EVD insertion during the study period. A total of 183 catheters were placed freehand, 66 neuronavigation-guided, and 45 ultrasound-guided; the mean Evans ratios were 0.33, 0.29, and 0.31, respectively. Whilst there was a tendency for lower rates of suboptimal placement were guidance was used, with rates of 10.6% and 15.6% for neuronavigation- and ultrasound-guidance, respectively, compared to 20.8% in freehand placement, this did not reach statistical significance (P = 0.168). However, pooling this data with two additional studies on meta-analysis found a significant reduction in the risk of suboptimal placement for image-guided vs. freehand EVDs (odds ratio: 0.50, 95% CI: 0.32-0.77, P = 0.002). Surgeon seniority and other procedure-related factors had no significant impact on EVD placement accuracy or complications. Our results, pooled with those of previous studies, suggest image-guided EVD placement significantly reduced the rate of suboptimally placed EVDs. We conclude in appropriately selected cases that image-guided EVD insertions may improve accuracy of catheter placements and reduce associated complications of the procedure.