Search

Introduction. The purpose of the present contribution is to perform a detailed anatomic and virtual reality three-dimensional stereoscopic study in order to test the effectiveness of the extended endoscopic endonasal approaches for selected anterior and posterior circulation aneurysms.Methods. The study was divided in two main steps: (1) simulation step, using a dedicated Virtual Reality System (Dextroscope, Volume Interactions); (2) dissection step, in which the feasibility to reach specific vascular territory via the nose was verified in the anatomical laboratory.Results. Good visualization and proximal and distal vascular control of the main midline anterior and posterior circulation territory were achieved during the simulation step as well as in the dissection step (anterior communicating complex, internal carotid, ophthalmic, superior hypophyseal, posterior cerebral and posterior communicating, basilar, superior cerebellar, anterior inferior cerebellar, vertebral, and posterior inferior cerebellar arteries).Conclusion. The present contribution is intended as strictly anatomic study in which we highlighted some specific anterior and posterior circulation aneurysms that can be reached via the nose. For clinical applications of these approaches, some relevant complications, mainly related to the endonasal route, such as proximal and distal vascular control, major arterial bleeding, postoperative cerebrospinal fluid leak, and olfactory disturbances must be considered.

Background Pituitary surgery is a continuous evolving specialty of the neurosurgeons' armamentarium, which requires precise anatomic knowledge, technical skills, and integrated culture of the pituitary pathophysiology. Actually it cannot be considered only from a technical standpoint, but rather a procedure resulting from the close cooperation among different specialists (e.g., ophthalmologists, neuroradiologists, endocrinologists, neurosurgeons, otorhinolaryngologists, anesthesiologists, neurophysiologists, pathologists, instrument manufacturers). Methods The “pure” endoscopic endonsal surgery is a procedure performed through the nose, with the endoscope alone throughout the whole approach and without any transsphenoidal retractor. The procedure consists of three main aspects: exposure of the lesion, removal of the relevant pathology, and reconstruction, going through three different steps, the nasal, the sphenoid, and the sellar phases. Conclusions The endoscopic approach offers some advantages due to the endoscope itself: a superior close-up view of the relevant anatomy and an enlarged working angle are provided with an increased panoramic vision inside the surgical area. Concerning results in terms of mass removal, relief of clinical symptoms, cure of the underlying disease, and complication rate, these are, at least, similar to those reported in the major microsurgical series, but patient compliance is by far better. Besides the advantages to the patients, the surgeons—because of the wider and closer view of the surgical target area and the increase of the scientific activity as from the peer-reviewed literature on the topic in the past 10 years, the smoothing of interdisciplinary cooperation—, and the institutions (shorter postoperative hospital stay and increase of the case load)— the adoption of endoscopy in transsphenoidal surgery has gained a strong foothold.

Advances in endoscopic endonasal skull base surgery have led to the development of new routes to areas beyond the midline skull base. Recently, feasible surgical corridors to the lateral skull base have been described. The aim of this study was to describe the anatomical exposure of the ventrolateral brainstem and posterior fossa through an extended endoscopic endonasal transclival transpetrosal and transcondylar approach. Six human heads were used for the dissection process. The arterial and venous systems were injected with red- and blue-colored latex, respectively. A pre- and postoperative computed tomography (CT) scan was carried out on every head. The endoscopic endonasal transclival approach was extended through an anterior petrosectomy and a medial condylectomy. A three-dimensional model of the approach was reconstructed, using a dedicated software, from the overlapping of the pre- and post-dissection CT imaging of the specimen. An extended endoscopic transclival approach allows to gain access through an extradural anterior petrosectomy and medial condylectomy to the anterolateral surface of the brainstem and the posterior fossa. Two main intradural anatomical corridors can be described: first, between the V cranial nerve in the prepontine cistern and the VII-VIII cranial nerves in the cerebellopontine and cerebellomedullary cistern; second, between the VII-VIII cranial nerves and the IX cranial nerve, in the premedullary cistern. Extending the transclival endoscopic approach by performing an extradural anterior petrosectomy and a medial condylectomy provides a safe and wide exposure of the anterolateral brainstem with feasible surgical corridors around the main neurovascular structures.