Stereotactic Ventriculostomy Guide.

Introduction Based on the anatomy of the frontal horn, a stereotactic ventriculostomy guidance system that does not need an elaborate setup and is suitable for ventricles of all sizes was developed. The objective of this paper is to describe this system and present the results of a cadaveric study in which this system was used. Method The system has a midline-based plate that is contoured to snugly fit the top of the head. It has two probe holders, one on each side at pre-set angles in coronal and sagittal planes, which enables the probe holders to point at the foramen of Monro. A cadaver study was done on eight donors. First, using the guidance system a 1.4 mm endoscope was inserted into the right frontal horn through a twist drill hole. Next, the scope was inserted into the right frontal horn on the same donors using the freehand method. Result With the guide, all eight ventricles were entered into on the first trial, and the foramen of Monro was visible end-on. With freehand technique: six ventricles were entered on the first try; however, the foramen of Monro was visible end-on only in one. In the other two, two to three attempts were needed. The guide facilitated 100% visibility for the end-on visibility of the foramen of Monro upon insertion and the results were statistically significant with t=7, df=7, p-value=0.000106. Conclusion This is a simple system, which is easy to use. The cadaveric study showed a high degree of accuracy to access the ventricles. The data shows significant improvement compared to the freehand technique.