Anterior Clinoidectomy: Intradural Step-by-Step En Bloc Removal Technique.

OBJECTIVE: Anterior clinoidectomy is an important and essential skill for skull base and cerebrovascular neurosurgeons. We present a 1-piece intradural anterior clinoidectomy, providing a step-by-step description of the technique, independently of anatomic variations. METHODS: Between 2014 and 2020, 128 patients (119 women and 9 men; average age, 54.6 years) underwent intradural anterior clinoidectomy during microsurgical clipping of carotid-ophthalmic aneurysms. RESULTS: The anterior clinoid process continues medially with the planum sphenoidale, over the optic nerve, laterally with the lesser wing of the sphenoid bone, and inferiorly with the optic strut, which is always found anteriorly to the clinoid segment of the internal carotid artery, and separates the optic canal from the superior orbital fissure. The proposed anterior clinoidectomy followed, one after the other, these 3 fixation points for the detachment of the anterior clinoid process. The main indication for intradural anterior clinoidectomy was the management of vascular lesions around paraclinoid (clinoidal and ophthalmic) segments of the internal carotid artery. Complications of the procedure included injury to the internal carotid artery or the ophthalmic artery, thermal damage to the optic nerve, and invasion of the sphenoid sinus or a pneumatized anterior clinoid process, which could lead to postoperative cerebrospinal fluid leakage. CONCLUSIONS: The anterior clinoidectomy technique described here minimizes the drilling surface for detachment of the anterior clinoid process and reduces operative time as well as the amount of bone dust produced by drilling. It also precisely delineates the localization of the optic strut, preventing carotid or optic nerve damage.

Microcephaly and Zika virus: neonatal neuroradiological aspects.

PURPOSE: The aim of this study is to describe some radiological features in the newborns with microcephaly caused by Zika virus infection during pregnancy. METHODS: We radiologically analyzed 13 cases of newborns with microcephaly born to mothers who were infected by the Zika virus in the early stage of pregnancy. RESULTS: The most frequently observed radiological findings were microcephaly and decreased brain parenchymal volume associated with lissencephaly, ventriculomegaly secondary to the lack of brain tissue (not hypertensive), and coarse and anarchic calcifications mainly involving the subcortical cortical transition, and the basal ganglia. CONCLUSIONS: Although it cannot be concluded that there is a definitive pathognomonic radiographic pattern of microcephaly caused by Zika virus, gross calcifications and anarchic distribution involving the subcortical cortical transition and the basal ganglia, in association with lissencephaly and in the absence of hypertensive ventriculomegaly, are characteristic of this type of infection.