Suchergebnisse

Abstract
Background Different types of skull base tumors and intracranial aneurysms may lead to compression of the optic pathways. Since most of them are biologically benign conditions, the first aim of surgery is preservation of optic nerves rather than the oncologic radicality.
Materials and methods Based on the progressive technical refinements coming from our institutional experience of optic nerve compression from aneurysms and extra-axial tumors, we analyzed the surgical steps to release nerves and chiasm during tumor debulking and aneurysm clipping.
Results We distinguished vascular and tumor lesions according to the main direction of optic nerve compression: lateral to medial, medial to lateral, inferior to superior, and anterior to posterior. We also identified four fundamental sequential maneuvers to release the optic nerve, which are (1) falciform ligament (FL) section, (2) optic canal unroofing, (3) anterior clinoid process drilling, and (4) optic strut removal. The FL section is always recommended when a gentle manipulation of the optic nerve is required. Optic canal unroofing is suggested in case of lateral-to-medial compression (i.e., clinoid meningiomas), medial-to-lateral compression (i.e., tuberculum sellae meningiomas), and inferior-to-superior compression (i.e., suprasellar lesions). Anterior clinoidectomy and optic strut removal may be necessary in case of lateral-to-medial compression from paraclinoid aneurysms or meningiomas.
Conclusions Preservation of the visual function is the main goal of surgery for tumors and aneurysms causing optic nerve compression. This mandatory principle guides the approach, the timing, and the technical strategy to release the optic nerve, and is principally based on the direction of the compression vector.

Abstract
Background and Objective Clipping is still considered the treatment of choice for middle cerebral artery (MCA) aneurysms due to their angioarchitectural characteristics as they are often bifurcation dysplasias, needing a complex reconstruction rather than a simple exclusion. Thus, maintaining this surgical expertise is of paramount importance to train of young cerebrovascular surgeons. To balance for the increasingly limited experience due the worldwide general inclination toward the endovascular approaches, it is important to provide to the young neurosurgeons rules and operative nuances to guide this complex surgery. We describe the technical algorithm we use to teach our residents to approach ruptured and unruptured MCA aneurysms, which may help to develop a procedural memory useful to perform an effective and safe surgery.
Materials and Methods We reviewed our last 10 years' institutional experience of about 400 cases of ruptured and unruptured MCA aneurysms clipping, analyzing our technical refinements and the difficulties in residents and young neurosurgeons teaching, to establish fundamental key-points and design a didactic algorithm that includes operative instructions and safety rules.
Results We recognized seven pragmatic technical key points regarding craniotomy, sylvian fissure opening, basal cisternostomy, proximal vessel control, lenticulostriate arteries preservation, aneurysm neck microdissection, and clipping to use as a didactic algorithm for teaching residents, and as operative instructions for inexperienced neurosurgeons.
Conclusion In the setting of clipping MCA aneurysms, respect for surgical rules is of paramount importance to perform an effective and safe procedure, ensure the best aneurysm exclusion, and preserve the flow in collaterals and perforators.

Abstract
Background Anterior communicating artery (AComA) aneurysms are the most common intracranial aneurysm, accounting for 25 to 38% of all cases. In spite of the advent of modern neurointerventional treatments, they still represent a strong indication for clipping in certain anatomical and clinical conditions. However, AComA aneurysms are the deepest located aneurysms of the anastomotic circle of Willis, with a complex spatial orientation, and they are fed by bilateral branches of the anterior circulations. Although, on one hand, these aneurysms represent the most complex ones of the anterior circulation, on the other hand, the experience of young neurosurgeons is increasingly limited. Therefore, respecting operative guidelines is crucial to achieve the best aneurysm exclusion and avoid fatal intraoperative complications.
Study Objective We describe the technical algorithm we use to teach young neurosurgeons how to approach AComA aneurysms and help them to develop a procedural memory needed to perform an efficient and safe surgery.
Materials and Methods We reviewed our last 10 years of institutional experience of > 200 cases of clipping ruptured and unruptured AComA aneurysms, analyzing our technical refinements and the difficulties in teaching residents and young neurosurgeons how to establish fundamental key points and design a didactic algorithm that includes operative instructions and safety rules.
Results We identified seven pragmatic technical key points regarding craniotomy, cisternostomy, gyrus rectus corticectomy, proximal control, perforators and Heubner preservation, aneurysm neck dissection, and clipping to use in a didactic algorithm for teaching residents and as operative instructions for inexperienced neurosurgeons.
Conclusion In the setting of clipping AComA aneurysms, respect for surgical rules is of paramount importance to perform an efficacious and safe procedure and ensure the best aneurysm exclusion and preservation of neurovascular structures.

Abstract
Background Causes of the nonaneurysmal subarachnoid hemorrhage (na-SAH) are still debated. Many studies confirmed the possible involvement of the intracranial venous system, in particular variants of the basal vein of Rosenthal.
Study Object The aim of this study is to investigate the role of extracranial venous system, in particular the jugular drainage, in the na-SAH pathophysiology.
Materials and Methods This is a multicenter retrospective study including patients suffering from na-SAH who were radiologically screened to exclude vascular malformations. The course of the internal jugular veins was evaluated to reveal any stenosis (caliber reduction >80%). Particular attention was paid at the passage between the styloid process and the arch of C1 to detect possible compression. As a control group, we enrolled patients who underwent CT angiograms and/or cerebral DSAs in the past 2 years.
Results We included 194 patients. The na-SAH group consisted of 94 patients, whereas the control group consisted of 100 patients. Fifty patients of the control group underwent a CT angiography for an ischemic cerebrovascular disease or trauma and 50 patients for an SAH due to a ruptured aneurysm. A significant jugular stenosis was found in 49 (52.1%) patients in the na-SAH group and in 18 (18%) patients in the control group. At univariate and multivariate analysis, the difference was statistically significant (p < 0.0001).
Conclusions This is the first study investigating the correlation between jugular stenosis and the occurrence of na-SAH. The impaired venous outflow due to reduced venous caliber could result in an engorgement of the upstream intracranial veins with transient hypertensive phases facilitating ruptures. Further larger prospective studies are necessary to confirm these data.