An overview of the use of the dorsum sellae and clival line as a guide in endoscopic third ventriculostomy: historical, anatomical and technical aspects.

Endoscopic third ventriculostomy (ETV) has become one of the fundamental procedures in the treatment of obstructive or non-communicating hydrocephalus nowadays. One of the main challenges faced by groups new to the technique, which determines its success, is the perforation of the floor of the third ventricle and entry into the prepontine cistern. In various descriptions of the technique, it is common to refer to the middle third of an imaginary line drawn between the mammillary bodies and the infundibular recess as the perforation point. However, this is often an arbitrary point that depends on different factors such as the patient's anatomy and the operator's level of experience. Our group believes that using the dorsum sellae and clival line as a reference point to guide this perforation and enter to the prepontine cistern can be helpful, providing neurosurgeons with a stable, consistent, and familiar anatomical landmark that reduces uncertainty regarding the technique. After conducting a literature search, we found limited representation of the topic we aim to address here. Therefore, the objective of this article is to provide a historical, anatomical, and technical review of the use of the dorsum sellae and clival line as a guide for performing ETV.