Septostomy and Monroplasty in Isolated Lateral Ventricle After Removal of a Third Ventricle Colloid Cyst: 2-Dimensional Operative Video.

Isolated unilateral hydrocephalus (IUH) is a condition caused by unilateral obstruction of the foramen of Monro.1 Etiopathogenic causes include tumors, congenital lesions, infective ventriculitis, intraventricular haemorrhage, and iatrogenic causes such as the presence of contralateral shunts.2,3 Neuroendoscopic management is considered the "gold-standard" treatment in IUH.4 Even if endoscopic septostomy and foraminoplasty in IUH are well-known procedures,5,6 IUH after an interhemispheric transcallosal transchoroidal approach for removal of a III ventricle colloid cyst is a complication barely described in literature. Video 1 describes this rare complication and the neuroendoscopic treatment adopted, including the operative room setup, patient's positioning, instrumentation needed, and a series of intraoperative tips for the performance of septostomy and Monroplasty via a single, precoronal burr hole. The scalp entry point and endoscope trajectory, homolateral to the dilated ventricle, were planned on the neuronavigation system. The avascular septal zone away from the septal veins and body of the fornix was reached, and the ostomy was performed. At the end of the procedure, Monroplasty was performed, too. The procedure was effective in solving the hydrocephalus and patient's clinical picture. No surgical complications occurred. Imaging demonstrated an evident and progressive reduction of enlarged lateral ventricle. In authors' opinion, the single burr-hole approach, ipsilateral to the enlarged ventricle, provides an optimal identification the intraventricular anatomy and allows Monroplasty to be performed, if deemed feasible during surgery. The patient consented to the procedure. The participants and any identifiable individuals consented to publication of their images.

Additive Manufacturing for Personalized Skull Base Reconstruction in Endoscopic Transclival Surgery: A Proof-of-Concept Study.

BACKGROUND: Endoscopic transnasal transclival intradural surgery is limited by a high postoperative cerebrospinal fluid leak rate. The aim of this study was to investigate the role of three-dimensional printing to create a personalized, rigid scaffold for clival reconstruction. METHODS: Two different types of clivectomy were performed in 5 specimens with the aid of neuronavigation, and 11 clival reconstructions were simulated. They were repaired with polylactide, three-dimensional-printed scaffolds that were manually designed in a computer-aided environment based either on the real or on the predicted defect. Scaffolds were printed with a fused filament fabrication technique and different offsets. They were positioned and fixed either following the gasket seal technique or with screws. Postdissection radiological evaluation of scaffold position was performed in all cases. In 3 specimens, the cerebrospinal fluid leak pressure point was measured immediately after reconstruction. RESULTS: The production process took approximately 30 hours. The designed scaffolds were satisfactory when no offset was added. Wings were added during the design to allow for screw positioning, but broke in 30% of cases. Radiological assessment documented maximal accuracy of scaffold positioning when the scaffold was created on the real defect; accuracy was satisfactory when the predicted clivectomy was performed under neuronavigation guidance. The cerebrospinal fluid leak pressure point was significantly higher when the scaffold was fixed with screws compared with the gasket technique. CONCLUSIONS: In this preclinical setting, additive manufacturing allows the creation of customized scaffolds that are effective in reconstructing even large and geometrically complex clival defects.

Transclival approaches for intradural pathologies: historical overview and present scenario.

Recently, endoscopic transsphenoidal transclival approaches have been developed and their role is widely accepted for extradural pathologies. Their application to intradural pathologies is still debated, but is undoubtedly increasing. In the past five decades, different authors have reported various extracranial, anterior transclival approaches for intradural pathologies. The aim of this review is to provide a historical overview of transclival approaches applied to intradural pathologies. PubMed was searched in October 2018 using the terms transcliv*, cliv* intradural, transsphenoidal transcliv*, transoral transcliv*, transcervical transcliv*, transsphenoidal brainstem, and transoral brainstem. Exclusion criteria included not reporting reconstruction technique, anatomical studies, reviews without new data, and transcranial approaches. Ninety-one studies were included in the systematic review. Since 1966, transcervical, transoral, transsphenoidal microsurgical, and, recently, endoscopic routes have been used as a corridor for transclival approaches to treat intradural pathologies. Each approach presents a curve that follows Scott's parabola, with evident phases of enthusiasm that quickly faded, possibly due to high post-operative CSF leak rates and other complications. It is evident that the introduction of the endoscope has led to a significant increase in reports of transclival approaches for intradural pathologies. Various reconstruction techniques and materials have been used, although rates of CSF leak remain relatively high. Transclival approaches for intradural pathologies have a long history. We are now in a new era of interest, but achieving effective dural and skull base reconstruction must still be definitively addressed, possibly with the use of newly available technologies.