A light on the dark side: in vivo endoscopic anatomy of the posterior third ventricle and its variations in hydrocephalus

Despite the technological advancements of neurosurgery, the posterior part of the third ventricle has always been the "dark side" of the ventricle. However, flexible endoscopy offers the opportunity for a direct, in vivo inspection and detailed description of the posterior third ventricle in physiological and pathological conditions. The purposes of this study were to describe the posterior wall of the third ventricle, detailing its normal anatomy and surgical landmarks, and to assess the effect of chronic hydrocephalus on the anatomy of this hidden region.