Endoscopic fenestration at the splenial-habenular junctional area for symptomatic cavum and tumor at the foramen of Monro: case reports and anatomical review

The splenial-habenular junctional area is an alternative site for neuroendoscopic fenestration to divert CSF flow into the quadrigeminal cistern in cases in which endoscopic third ventriculostomy is not amenable. In some patients with obstructive hydrocephalus, the splenium of the corpus callosum can be elevated from the habenular complex. This exposes the membranous connection between the splenium and habenula, which can be fenestrated to divert the CSF flow into the quadrigeminal cistern. This technique can be performed in patients in whom the foramen of Monro or the third ventricle is blocked by a lesion. Here, the authors present 3 complex cases that were managed by neuronavigation-guided transventricular transcavum endoscopic fenestration of the splenial-habenular junctional area. These cases may increase the knowledge and understanding of the anatomy of this region.