Comparison of the lateral supraorbital approach and endoscopic endonasal transclival approach to basilar apex aneurysms among other possible applications of the endoscopic endonasal technique to vascular neurosurgery: anatomic and clinical study.

Abstract Introduction. The expansion of the endoscopic endonasal approach in neurosurgery during the last three decades recently led the neurosurgical clinical interest to the investigation of further application of this technique, namely to neurovascular pathologies. Cadaver dissections studies have represented the milestone in the progressive application of this technique. Integrating anatomical studies with advanced visualization tools and quantification methods increases their impact toward clinical application. Material and methods. The main endoscopic endonasal approaches were performed and exposure of the vascular intracranial structures was analyzed: the anterior communicating artery complex was investigated through the transplanum transtuberculum approach; the transsphenoidal approach to the sellar area was performed for the exposure of the intracavernous internal carotid artery; the basilar artery was exposed by means of the endoscopic endonasal transclival approach, and the vertebral arteries through the extended endonasal approach to the craniovertebral junction. Possible clinical application of each approach was investigated during anatomical dissections upgraded with imaging and quantification methods. Results. The transtuberculum transplanum approach allows for the exposure and control of the anterior communicating artery complex; the relationship between the proximal anterior cerebral artery, gyrus rectus, and optic chiasm is the main determinant for the exposure and control of the vessel. Temporary occlusion of the internal carotid artery with a Fogarty balloon catheter through the endoscopic transsphenoidal route might be another maneuver that is useful for obtaining intraoperative control of the vessel. The endoscopic transclival approach may be considered a minimally invasive route to the basilar apex in the presence of specific anatomical and pathological features. Comparative analysis of the anatomical exposure of the vertebro-basilar junction as obtained through transcranial and endoscopic endonasal approaches may be helpful in unlocking this complex skull base area. Conclusions. The introduction of the endoscopic endonasal approaches for the treatment of cerebrovascular pathologies represents the most advanced and innovative step forward of the skull base endoscopic endonasal surgical technique. The present PhD research activity may add relevant anatomical and clinical information to the rather sparse literature directly focused on surgical indication of the endoscopic endonasal approaches to vascular neurosurgery.