Suboccipital Midline Approaches to the 4th Ventricle: Step-by-Step Cadaveric Dissection for Trainees and Anatomic Review of the Adjacent Cerebellopontine Angle

Introduction: Safe, effective access to the fourth ventricle for resection of intraventricular and skull base tumors remains challenging given the depth of location, restricted posterior fossa boundaries, and surrounding eloquent neuroanatomy. Resources depicting traditional transventricular routes predominantly emphasize complex three-dimensional relationships rather than a practical operative guide targeted toward all levels of training. The objective of this study was to create a reproducible step-by-step guide for obtaining transventricular access to the fourth ventricle and adjacent cranial base structures.