Innovations in Assist Devices to Improve External Ventricular Drain Placement

Introduction: The insertion of an external ventricular drain (EVD) involves navigating a catheter into a lateral ventricle of the brain to allow the drainage of cerebrospinal fluid (CSF). This can be a life-saving procedure in emergency situations. This is classically completed freehand, using landmarks on the skull to align the trajectory. However, this technique is vulnerable to misplacement and can lead to catheter malposition. Emerging technologies have been suggested as solutions to improve EVD placement accuracy and claim to reduce adverse effects. The objective of this observation is to examine recent technology developed to improve EVD placement.

Methods: A qualitative review of literature was completed on publications collected from 6 databases: PUBMED, Medline, Web of Knowledge, Scopus, ClinicalTrials.Gov, and Google Scholar. The google scholar patent search was also used to query all patented devices. Relevant studies presented technology and innovations for external ventricular device (EVD) placement.

Results: The article and patent search returned 19 devices for EVD placement within 4 categories: ultrasound guidance, electromagnetic guidance, CT-based guidance, and mechanical assist devices. The potential benefits of these devices range from real-time feedback for adjustments during insertion to reducing the number of passes and improving placement accuracy. Downsides include cost of these devices and procedural changes that may increase the overall procedure time. A survey of neurosurgeons and residents found that 51.7% preferred image guidance, 41.6% preferred freehand technique, and the 6.7% preferred the Ghajar guide in patients with slit ventricles.

Conclusion : Although freehand technique has been the traditional method for EVD insertion, a number of guidance technologies have been developed to improve placement accuracy. Image-guided procedures have become the preferred method in patients with complicated anatomy. However, changes in procedure time, device availability, and cost have limited the use of these technologies.