Placement of External Ventricular Drains Using an Average Model

Abstract

Purpose: Freehand placement of external ventricular drainage is not sufficiently accurate and precise. In the absence of high quality pre-operative 3D images, we propose the use of an average model for guidance of ventricular catheters. Methods: The model was segmented to extract the ventricles and registered to five normal volunteers. The proposed method was validated by comparing the trajectory resulting from the use of the average model to the use of volunteer-specific images. Results: The distances between the target points in the model and the volunteer-specific images at the left and right foramen of Monroe were computed (Mean$\pm$std: 5.74$\pm$1.39 mm and 6.00$\pm$1.17 mm for the left and right side respectively). We also compared the angles between the trajectories resulting from the use of volunteer specific data and the average model and the engagement of the trajectories with the frontal horn of the ipsilateral ventricle. Conclusions: Although an average model for guidance of a surgical procedure has a number of limitations, our initial experiments show that the use of a model might provide sufficient guidance for determination of the angle of insertion. Future work will include further clinical testing and possible refinement of the model.