Development of Patient-Specific 3-Dimensional Graphical Entry-Point Maps for External Ventricular Drain Insertion.

Abstract

External ventricular drains (EVDs) are mainly inserted free-hand perpendicular to the skull through known entry points, but only 40%-50% of cases result in acceptable position. Nonideal trajectories increase the risk of complications. Using 90 patient cases, we developed a visualization method to identify regions on the skull that result in successful EVD insertion, while incorporating precalculated uncertainties in the trajectory. Feasibility of the method was evaluated by determining the number of possible trajectories. There was a significant difference in hit rate between hydrocephalic or trauma and asymptomatic patients. Overall, the average catheter length calculated was concordant with ranges reported in prior EVD studies (maximum average = 51.4 ± 6.4 mm). A new patient-specific visualization paradigm was developed to optimize the insertion point for EVD. The visualization tool identifies new insertion sites but also confirms the validity of existing ones used in the current standard of care.