Surgeon's Eyes on the Relevant Surgical Target.

The resolution of the naked eye has been a challenge for the neurosurgical endeavor since the very first attempts of cranial surgery, and advances have been achieved over the centuries, driven by a synergism between the application of emerging technology into the surgical environment and the expansion of the capabilities of neurosurgery. The understanding of the principles of the optical properties of lenses by Abbè (1840-1905) led to the introduction of loupes in the surgical practice, increasing the visual performance during macroscopic procedures. Modern neurosurgery began with the possibility of illumination and magnification of the surgical field as provided by the microscope. Pioneering contributions from Donaghy and Yasargil opened the way to the era of minimalism with reduction of operative corridors and surgical trauma through the adoption of the microsurgical technique. Almost at the same time, engineering mirabilia of Hopkins in terms of optics and lenses allowed for introduction of rigid and flexible endoscopes as a viable tool in neurosurgery. Nowadays, neurosurgeons are aware of and confident using effective and modern tools of visualization in their armamentarium. Herein we present a cogent review of the evolution of visualization tools in neurosurgery, with a special glimpse into the current development and future achievements.

Primary ectopic orbital craniopharyngioma.

Craniopharyngiomas (CP) ectopic localizations off the midline outside the sellar-suprasellar region are very rare and most often associated to secondary tumor dissemination, being primary ectopic CPs extremely unusual. We herein report the first case of a primary ectopic craniopharyngioma within the orbit. A 15-year-old patient presented with progressive right ptosis, proptosis, and retro ocular pain. Magnetic resonance imaging (MRI) showed a predominantly cystic lesion, occupying the superolateral right corner of the orbit, outside the intraconal space with no evidence of intracranial involvement. An endoscopic transorbital eyelid approach was adopted. Pathology report disclosed a primary ectopic craniopharyngioma.

Multicenter external validation of the Zurich Pituitary Score.

PURPOSE: Recently, the Zurich Pituitary Score (ZPS) has been proposed as a new quantitative preoperative classification scheme for predicting gross total resection (GTR), extent of resection (EOR), and residual tumor volume (RV) in endoscopic pituitary surgery. We evaluated the external validity of the ZPS. METHODS: In three reference centers for pituitary surgery, the ZPS was applied and correlated to GTR, EOR, and RV. Furthermore, its inter-rater agreement was assessed. RESULTS: A total of 485 patients (53% male; age, 53.8 ± 15.7) were included. ZPS grades I, II, III, and IV were observed in 110 (23%), 270 (56%), 64 (13%), and 41 (8%) patients, respectively. GTR was achieved in 358 (74%) cases, with mean EOR of 87.6% ± 20.3% and RV of 1.42 ± 2.80 cm3. With increasing ZPS grade, strongly significant decreasing trends for GTR (I, 92%; II, 77%; III, 67%; IV, 15%; p < 0.001) and EOR (I, 93.8%; II, 89.9%; III, 88.1%; IV, 75.4%; p < 0.001) were found. Similarly, RV increased steadily ([cm3] I, 0.16; II, 0.61; III, 2.01; IV, 3.84; p < 0.001). We observed intraclass correlation coefficients of 0.837 (95% CI, 0.804-0.865) for intercarotid distance and 0.964 (95% CI, 0.956-0.970) for adenoma diameter, and Cohen's kappa of 0.972 (95% CI, 0.952-0.992) for the ZPS grades. CONCLUSIONS: Application of the ZPS in three external cohorts was successful. The ZPS generalized well in terms of GTR, EOR, and RV; demonstrated excellent inter-rater agreement; and can safely and effectively be applied as a quantitative classification of adenomas with relevance to surgical outcome.

The endoscopic endonasal approach for pediatric craniopharyngiomas: the key lessons learned.

PURPOSE: The aim of this study is to highlight the role of the endoscopic endonasal approach (EEA) in pediatric craniopharyngiomas by reviewing our experience and the key lessons learned from the application of this approach in children. METHODS: Between 1998 and 2017, 12 pediatric craniopharyngiomas were treated via EEA at our institution. Demographic data, preoperative assessment, tumor features, surgical results, complications, and recurrences were analyzed. RESULTS: Visual defects were the most frequent presenting sign. Seven craniopharyngiomas were infradiaphragmatic, and five were supradiaphragmatic. The EEA was successfully performed in all cases with no complication related to children's sinonasal anatomy. Gross total resection (GTR) rate was of 75%. Endocrinological disturbances improved in one case (20%) and worsened in three (60%). New onset of diabetes insipidus was observed in four (36%) children. Visual defect improved in 91% of cases, with no new postoperative deficit. Postoperative cerebrospinal fluid (CSF) leak occurred in one patient (8%). Three patients (27%) experienced tumor regrowth, and one craniopharyngioma recurred (mean follow-up, 78 months). CONCLUSIONS: The EEA offers a straight route to the sellar-suprasellar, making it the ideal approach for pediatric infradiaphragmatic craniopharyngiomas. In supradiaphragmatic craniopharyngiomas, the extended EEA provides a clearer and close-up visualization of the tumor-hypothalamus interface, which can grant better results in terms of quality of life. The pediatric skull base anatomy should not represent a contraindication for the endoscopic technique. Larger series encompassing a wider spectrum of pediatric craniopharyngiomas are needed to further support the benefits of this surgical approach.

The extended endoscopic endonasal transplanum transtuberculum approach to the anterior communicating artery complex: anatomic study.

BACKGROUND: When performing a transplanum transtuberculum approach, dealing with the anterior communicating artery (ACoA) complex is inevitable. The aim of this study is to provide quantitative anatomical information regarding the ACoA complex and its bony and neural relationships, when exposed through this approach. METHOD: The endoscopic endonasal transplanum transtuberculum approach was performed on ten human cadaver heads. In each specimen, radiological studies were performed. A three-dimensional model of the approach was reconstructed. Measured parameters were: exposure of the vessels; distance between the proximal anterior cerebral artery (A1) and the optic chiasm; dimension of the bone opening. The feasibility to perform clip placement was graded as "possible" or "not possible". RESULTS: Dimension of bone opening varied from 88 to 53 mm(2). The ACoA was exposed for 3 mm ± 2 mm, A1 for 17 mm ± 9 mm, the distal anterior cerebral artery (A2) for 12 mm ± 3 mm, the recurrent artery of Heubner (RAH) for 16 mm ± 4 mm. Clip placement was possible on the ACoA, A2, and distal segment of A1 in all cases, and on the proximal segment of A1 in one instance. The distance between A1 and the optic chiasm measured 9 mm ± 2 mm. CONCLUSIONS: The ACoA, A2, and the distal segment of A1 can be visualized and controlled through the transplanum transtuberculum approach. The relationship between A1, gyrus rectus, and optic chiasm is the main determinant for the exposure and control of the vessel. The olfactory nerve can represent a surgical landmark for the identification of the A1 origin. The whole course of the RAH can be visualized trough this approach.

Extended endoscopic endonasal transclival approach to the ventrolateral brainstem and related cisternal spaces: anatomical study.

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.

Endoscopic transorbital and transcranial multiportal resection of a sphenoorbital meningiomas with custom bone 3D printing reconstruction: Case report.

BACKGROUND: Sphenoorbital meningiomas (SOM) harbor intrinsic features that render their surgical management and the reconstruction of the resulting bony defect overtly challenging. METHODS: A 70-year-old woman, harboring a long-standing left frontotemporal bony swelling conservatively managed, presented with progressive left proptosis. Radiological features were consistent with an en plaque SOM. A one-step multiportal transcranial and endoscopic transorbital approach (TOA) with custom bone three-dimensional (3D) printing reconstruction using polymethylmethacrylate (PMMA) was scheduled. RESULTS: Postoperative functional and aesthetic results were excellent, with proptosis and calvarian deformity resolution. Tumor subtotal resection was achieved. Histopathological diagnosis confirmed a transitional meningioma (WHO grade I). CONCLUSIONS: The endoscopic TOA, isolated or as part of a multiportal strategy, has entered the surgical armamentarium for the treatment of SOMs. A customized PMMA cranioplasty can be considered a possible option for the reconstruction of large bony defects in a one-step fashion.

Systematic review of transcranial and endoscopic endonasal approaches for craniopharyngiomas in children: is there an evolution?

OBJECTIVE: The optimal surgical approach for pediatric craniopharyngiomas (CPs) remains a matter of debate, with selection bias classically precluding a fair comparison of outcomes between the transcranial approach (TCA) and endoscopic endonasal approach (EEA). The purpose of this systematic review was to analyze the current role of EEA in the treatment of pediatric CPs and to determine whether, upon expansion of its indications, a comparison with TCA is valid. METHODS: A systematic review of English-language articles published between February 2010 and June 2022 was performed to identify studies in the MEDLINE (PubMed) and Embase databases reporting on the resection of pediatric CPs. Included were articles reporting on pediatric CPs removed through TCA or EEA. Case reports, review articles, and earlier or less comprehensive series by the same center were excluded. Baseline characteristics and outcomes were analyzed. Prediction intervals (PIs), heterogeneity (Q, I2, and τ2 statistics), and publication bias (funnel plot analysis) were assessed. RESULTS: A total of 835 patients underwent TCA (18 articles) and 403 patients underwent EEA (19 articles). Preoperatively, the mean patient age (p = 0.055, PI = 5.05-15.11), visual impairment (p = 0.08, PI = 19.1-90.5, I2 = 80%), and hypothalamic syndrome (p = 0.17, PI = 6.5-52.2, I2 = 62%) did not significantly differ between the EEA and TCA groups. Endocrine deficit (anterior pituitary deficit [p < 0.001, PI = 16.5-92.9, I2 = 81%] and diabetes insipidus [p < 0.001, PI = 6.3-60.6, I2 = 43%]) was more frequent in the EEA group. Hydrocephalus and signs/symptoms of raised intracranial pressure were significantly higher (p < 0.001, PI = 5.2-73.3, I2 = 70% vs p < 0.001, PI = 4.6-73, I2 = 62%, respectively) in the TCA group. Recurrent lesions (p = 0.52, PI = 2.7-87.3, I2 = 13%), tumor size (p = 0.25, PI = 22.1-56.8), third ventricle involvement (p = 0.053, PI = 10.9-81.3, I2 = 69%), and hypothalamic involvement (p = 0.06, PI = 8.5-83.6, I2 = 79%) did not differ significantly between the approaches. EEA was preferred (p = 0.006, PI = 26.8-70.8, I2 = 40%) for sellar-suprasellar CPs, whereas TCA was preferred for purely suprasellar CPs (p = 0.007, PI = 13.5-81.1, I2 = 61%). There was no difference between the approaches for purely intrasellar lesions (p = 0.94, PI = 0-62.7, I2 = 26%). The breadth of PIs, I2 values, and analysis of publication bias showed substantial variability among the pooled data, hindering the possibility of outcome meta-analyses. CONCLUSIONS: With the adoption of extended approaches, the use of EEA became appropriate for a wider spectrum of pediatric CPs, with associated excellent outcomes. Although a fair comparison between outcomes in the EEA and TCA groups was hindered because of the differences in patient populations and tumor subtypes, given the increased versatility of EEA and improved expertise in its use, surgeons can now select the optimal surgical approach based on the unique benefits and drawbacks of each pediatric CP.

Linear Scalp Incision in Brain Tumor Surgery: Intraoperative and Postoperative Considerations.

BACKGROUND: Although the linear scalp incision is commonly used in neurosurgical practice, a systematic study elucidating its pros and cons in a specific surgical setting is lacking. Herein, we analyzed our experience with linear scalp incision in brain tumor surgery and the impact on intraoperative variables and postoperative complications. METHODS: Patients undergoing brain tumor surgery (January 2014-December 2021) at 2 neurosurgical departments were included and divided into 2 groups: linear or flap scalp incision. Patients' demographics characteristics, surgical variables, and wound-related complications were analyzed. RESULTS: More than a total of 1036 craniotomies, linear incision (mean length 6cm) was adopted in 282 procedures (27.2%). Mean maximum diameter of the craniotomy was 5.25 cm, with no statistical difference between the 2 groups. In emergency surgery (36 cases), the linear and flap incisions were used indifferently. Linear incision was predominant in supratentorial and suboccipital lesions. Flap incision was significantly more frequent among meningiomas (P < 0.01). Neuronavigation, operative microscope, and subgaleal drain were more frequently used in the flap scalp incision group (P = 0.01). Overall complication rate was comparable to flap scalp opening (P = 0.40). CONCLUSIONS: The use of the linear incision was broadly applied for the removal of supratentorial and suboccipital tumors granting adequate surgical exposure with a low rate of postoperative complications. Tumors skull base localization resulted the only factor hindering the use of the linear incision. The choice of 1 incision over another didn't show to have any impact on intraoperative and postoperative variables, and it remains mainly based on surgeon expertise/preference.

Indocyanine green videoangiography (ICGV)-guided surgery of parasagittal meningiomas occluding the superior sagittal sinus (SSS).

BACKGROUND: Maximal safe resection is the goal of correct surgical treatment of parasagittal meningiomas, and it is intimately related to the venous anatomy both near and directly involved by the tumor. Indocyanine green videoangiography (ICGV) has already been advocated as an intra-operative resourceful technique in brain tumor surgery for the identification of vessels. The aim of this study was to investigate the role of ICGV in surgery of parasagittal meningiomas occluding the superior sagittal sinus (SSS). METHOD: In this study, we prospectively analyzed clinical, radiological and intra-operative findings of patients affected by parasagittal meningioma occluding the SSS, who underwent ICGV assisted-surgery. Radiological diagnosis of complete SSS occlusion was pre-operatively established in all cases. ICGV was performed before dural opening, before and during tumor resection, at the end of the procedure. RESULTS: Five patients were included in our study. In all cases, ICGV guided dural opening, tumor resection, and venous management. The venous collateral pathway was easily identified and preserved in all cases. Radical resection was achieved in four cases. Surgery was uneventful in all cases. CONCLUSIONS: Despite the small number of patients, our study shows that ICG videoangiography could play a crucial role in guiding surgery of parasagittal meningioma occluding the SSS. Further studies are needed to define the role of this technique on functional and oncological outcome of these patients.

5-aminolevulinic acid (5-ALA) fluorescence guided surgery of high-grade gliomas in eloquent areas assisted by functional mapping. Our experience and review of the literature.

BACKGROUND: Only few data are available on the specific topic of 5-aminolevulinic acid (5-ALA) guided surgery of high-grade gliomas (HGG) located in eloquent areas. Studies focusing specifically on the post-operative clinical outcome of such patients are yet not available, and it has not been so far explored whether such approach could be more suitable for some particular subgroups of patients. METHODS: Patients affected by HGG in eloquent areas who underwent surgery assisted by 5-ALA fluorescence and intra-operative monitoring were prospectively recruited in our Department between June 2011 and August 2012. Resection rate was reported as complete resection of enhancing tumor (CRET), gross total resection (GTR) >98 % and GTR > 90 %. Clinical outcome was evaluated at 7, 30, and 90 days after surgery. RESULTS: Thirty-one patients were enrolled. Resection was complete (CRET) in 74 % of patients. Tumor removal was stopped to avoid neurological impairment in 26 % of cases. GTR > 98 % and GTR > 90 % was achieved in 93 % and 100 % of cases, respectively. First surgery and awake surgery had a CRET rate of 80 % and 83 %, respectively. Even though at the first-week assessment 64 % of patients presented neurological impairment, there was a 3 % rate of severe morbidity at the 90th day assessment. Newly diagnosed patients had a significantly lower morbidity (0 %) and post-operative higher median KPS. Both pre-operative neurological condition and improvement after corticosteroids resulted significantly predictive of post-operative functional outcome. CONCLUSIONS: 5-ALA surgery assisted by functional mapping makes high HGG resection in eloquent areas feasible , through a reasonable rate of late morbidity. This emerges even more remarkably for selected patients.

Endoscopic Endonasal Approach for Tuberculum Sellae Meningioma: 2-Dimensional Operative Video.

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: Ideal indications for tuberculum sellae meningiomas (TSM) removal through endoscopic endonasal approach (EEA) are midline tumors (<3.5 cm), possibly with no optic canal invasion and no vessels encasement. The EEA is favored by a wide tuberculm sellae (TS) angle and a deep sella at the sphenoid sinus (SS). 1 Adequate removal of paranasal structures provides a wider surgical corridor ensuring exposure at the suprasellar area and safe instruments manuevrability. 2. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: The endoscopic transtuberculum transplanum approach allows for wide suprasellar intradural exposure. 3 Removal of the supraoptic recess (SOR) provides further lateral extension over the planum sphenoidale (PS) and proper management of dural involvement at the optic canal. 4. ESSENTIAL STEPS OF THE PROCEDURE: The patients have consented to the procedure. Bone removal starts at the upper sella and TS and is extended anteriorly over the PS and laterally, upon needs, at the SORs. On dural opening, tumor devascularization, dedressing, debulking, and dissection are run. Skull base reconstruction is performed using the 3F technique. 5. PITFALLS/AVOIDANCE OF COMPLICATIONS: In those cases with vessel encasement, possibility of achieving total resection has to be balanced with risk of vascular injury. 6 Optic canal dural invasion precludes tumor total removal; however, bony decompression is maximal using the EEA. Concerning postoperative cerebrospinal fluid fistula, nowadays the rates have dropped to <2%. VARIANTS AND INDICATIONS FOR THEIR USE: A wider skull base osteodural opening allows for the removal of selected meningiomas extending to the PS and cribriform plate.

Endoscopic endonasal approach for infradiaphragmatic craniopharyngiomas: a multicentric Italian study.

OBJECTIVE: Infradiaphragmatic craniopharyngiomas (ICs) represent a distinct subtype, harboring a sellar-suprasellar origin and generally growing in the extra-arachnoidal space contained by the diaphragma sellae. They have been considered ideal for surgical removal through the transsphenoidal approach since the 1960s. The authors present a multicentric national study, intending to selectively analyze IC behavior and the impact of the transsphenoidal endoscopic endonasal approach (EEA) on surgical outcomes. METHODS: Craniopharyngiomas that were intraoperatively recognized as infradiaphragmatic and removed with standard EEA between 2000 and 2021 at 6 Italian neurosurgical departments were included in the study. Clinical, radiological, and surgical findings and outcomes were evaluated and reviewed. RESULTS: In total, 84 patients were included, with 45.23% identified as pediatric cases and 39.28% as having recurrent tumors. The most common presenting symptoms were endocrine (75%), visual (59.52%), and hypothalamic (26.19%) disorders. ICs were classified as extending below (6 intrasellar and 41 occupying the suprasellar cistern) or above (26 obliterating the anterior recesses of the third ventricle and 11 extending up to the foramina of Monro) the chiasmatic cistern. Gross-total resection (GTR) was achieved in 54 cases (64.28%). Tumor extension above the chiasmatic cistern and calcifications were associated with lower likelihood of GTR. The cumulative rate of postoperative complications was 34.53%, with CSF leak being the most common (14.28%). Endocrine, visual, and hypothalamic functions deteriorated postoperatively in 41/78 patients (52.56%), 5/84 (5.95%), and 14/84 (16.67%), respectively. Twenty-eight patients (33.33%) had recurrence during follow-up (mean 63.51 months), with a mean 5-year progression-free survival (PFS) rate of 58%. PFS was greater in patients who achieved GTR than patients with other extent of resection. CONCLUSIONS: This is the largest series in the literature to describe ICs removed with standard EEA, without the need for additional bone and dural opening over the planum sphenoidale. EEA provides a direct route to ICs, the opportunity to manage lesions extending up to the third ventricle without breaching the diaphragma, and high rates of GTR and satisfactory clinical outcomes. Increased surgical complexity and morbidity should be expected in patients with extensive suprasellar extension and involvement of the surrounding vital neurovascular structures.

Endoscopic transorbital eyelid approach for the removal of an extraconal cavernous venous malformation: Case report.

Cavernous venous malformations (CVMs) are one of the most common benign primary orbital lesions in adults and the second most frequent cause of unilateral proptosis. Extraconal location is extremely rare, representing a favorable condition as compared to intraconal, as lesions at this level often adhere to orbital muscles and optic nerve. Herein, we report the case of a 50-year-old patient, who came to our attention because of progressive painless right axial proptosis. Magnetic resonance images were consistent with an extraconal CVM, occupying the superior temporal compartment of the orbit. Successful removal of the lesion was achieved through an endoscopic transorbital eyelid approach. The present case confirms the safety and efficacy of the endoscopic transorbital eyelid approach.

VITOM®-3D: preliminary experience with intradural extramedullary spinal tumors.

BACKGROUND: In the last decade, application of the high-definition exoscope to different neurosurgical procedures has been reported in the literature. We described the first experience with the VITOM®-3D (Video Telescope Operating Microscope, Karl Storz Endoscopy, Tuttlingen, Germany) for the surgical treatment of intradural extra-medullary tumors. METHODS: Five neurosurgical procedures for the removal of intradural extra-medullary tumors were performed with the VITOM®-3D. Patients' population, feasibility of surgery under the exoscope visualization, VITOM®-3D's technical and optical characteristics, and surgical outcome were analyzed. RESULTS: All surgeries were performed following the common steps of spinal neurosurgical intradural procedures. The exoscope offered excellent, magnified, and brilliantly illuminated high-definition images of the surgical field in all the described cases. All the reported surgical operations were successfully completed under exoscope magnification from both the technical as well as the clinical points of view. No complications potentially related to the use of the exoscope occurred. Working environment ergonomics and trainees learning experience were the most relevant benefits associated with the use of exoscope. CONCLUSIONS: VITOM®-3D may represent a valid visualization tool in spinal procedure for intradural extra-medullary tumors. Our preliminary experience can be useful in better define the role of VITOM®-3D in neurosurgery.

The Fate of Fat Graft in Extended Endoscopic Transtuberculum-Transplanum Approaches.

OBJECTIVE: To analyze the long-term fate of autologous fat graft in skull base reconstruction after an extended endoscopic transtuberculum-transplanum approach. METHODS: Data from 98 consecutive patients undergoing a transtuberculum-transplanum approach and skull base reconstruction using the 3F technique between June 2017 and January 2022 were retrospectively analyzed. Fat graft volume was measured on postoperative day 1 computed tomography scan and early (≤15 days), 3-month, and 1-year magnetic resonance imaging scans. Fat graft volumes and resorption rate were calculated in patients with a complete radiological follow-up and correlated to demographic, pathological, and surgical features. RESULTS: Fat volumes and resorption rate were calculated in 55 patients. Mean volume of fat on postoperative day 1 computed tomography scan was 3.58 ± 1.89 cm3 and on early, 3-month, and 1-year postoperative magnetic resonance imaging scans was 2.45 ± 1.57 cm3, 1.40 ± 0.76 cm3, and 0.92 ± 0.56 cm3, respectively. Resorption rate was 44% after 3 months and 67% after 1 year. Resorption rate did not significantly correlate with demographic, pathological, and surgical features. Cerebrospinal fluid leak requiring redo surgery occurred in 1 patient (1/98, 1.2%). There were 6 cases of visual worsening (6/98, 6.1%); no cases correlated to fat overpacking. No delayed complications at the donor site or at the grafting site were noted. CONCLUSIONS: Autologous fat graft in skull base reconstruction is observed to shrink significantly over time, reaching 67% in 1 year. Its use is associated with excellent outcomes, making it a favored material for skull base reconstruction.

Midline Skull Base Meningiomas: Transcranial and Endonasal Perspectives.

Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. The state of the art of skull base meningiomas accounts for both transcranial, or high, and endonasal, or low, routes. A comprehensive review of the pertinent literature was performed to address the surgical strategies and outcomes of skull base meningioma patients treated through a transcranial approach, an endoscopic endonasal approach (EEA), or both. Three databases (PubMed, Ovid Medline, and Ovid Embase) have been searched. The review of the literature provided 328 papers reporting the surgical, oncological, and clinical results of different approaches for the treatment of skull base meningiomas. The most suitable surgical corridors for olfactory groove, tuberculum sellae, clival and petroclival and cavernous sinus meningiomas have been analyzed. The EEA was proven to be associated with a lower extent of resection rates and better clinical outcomes compared with transcranial corridors, offering the possibility of achieving the so-called maximal safe resection.

Extended endonasal approaches for pituitary adenomas.

Pituitary adenomas with significant extension beyond the sellar boundary, large size, asymmetrical shape and subarachnoid space invasion, although rare, represent a therapeutic challenge. The invasiveness of the tumor itself often limits the potential for complete tumor resection and increases the likelihood of intraoperative or postoperative complications, regardless of the approach. The extended endoscopic endonasal approach has been proposed as a valid alternative to the transcranial route for the treatment of certain pituitary adenomas not suitable to the standard transsphenoidal approach. Thanks to the wide and close up view provided by the endoscope via the appropriate expanded bone removal at the skull base, this technique offers, in an adequate working space, a safe exposure of the tumor and surrounding anatomical structures, at the supra-, para-, and retro-sellar areas. It stands clear that the primary goal of this approach remains the maximum allowed resection with preservation of neurological and endocrine functions. Herein, we debate the extended endoscopic endonasal technique for the treatment of pituitary adenomas, with the aim of underlying its indications, pitfalls, advantages, and limitations.

Anatomical Assessment of the Endoscopic Assisted Lateral Supraorbital Approach and Endoscopic Endonasal Transclival Approach to Basilar Apex Aneurysms.

AIM: To assess the feasibility of using an endoscopic-assisted lateral supraorbital (LSO) approach and an endoscopic endonasal transclival approach (EETA) for basilar apex (BAX) aneurysms. MATERIAL AND METHODS: Ten cases with LSO approaches, with or without posterior clinoidectomy and endoscopic assistance, and 10 cases with EETA, with or without drilling of the dorsum sellae, were performed on 20 cadaveric heads. Anatomical exposure and surgical freedom at the BAX were evaluated. RESULTS: Anatomical exposure provided by the LSO approach was limited to the BAX and ipsilateral posterior cerebral artery (PCA) and increased with a mean value of 5.0 mm after posterior clinoidectomy; the basilar artery, contralateral PCA, and superior cerebellar arteries (SCAs) were visualized in all cases. Accordingly, surgical freedom was larger. Endoscopic assistance provided a significant increase in basilar artery exposure; however, surgical freedom did not increase markedly. The main advantage of EETA was the greatest exposure of the basilar artery. With drilling of the dorsum sellae, anatomical exposure increased by a mean value of 3.4 mm, and provided the greatest amount of surgical freedom and visualization of the basilar artery terminal bifurcation and of the SCAs in all cases. CONCLUSION: The endoscopic-assisted LSO approach and the EETA may represent a feasible approach for treatment of BAX aneurysms lying within 5.0 mm below and within 3.4 mm above the dorsum sellae.