Midline Anterior Skull Base Research Articles

Spatial Distribution of Meningiomas: A Magnetic Resonance Image Atlas.

The size and anatomic location of meningiomas have been shown to correlate with distinct clinical manifestations, histopathological subtypes, and surgical risk. However, meningioma anatomic origin sites can be obscured in large tumors and those crossing compartments. We therefore sought to apply unbiased lesion mapping to localize intracranial meningioma distributions and their association with biology and grade. MRI scans, World Health Organization (WHO) grade, and a molecularly Integrated Grade (IG) derived from cytogenetics were analyzed from adult patients with intracranial meningiomas. Semi-automated tumor segmentation was performed on T1-weighted contrast-enhanced MRI. We used the voxel-based lesion mapping technique to generate a meningioma atlas, mapping spatial frequency and correlating with tumor grades. Of 881 patients with meningioma (median age: 57 years, 68.8% female), 589 were WHO grade 1 (66.8%), 265 WHO grade 2 (30.1%), and 27 WHO grade 3 (3.1%) with a median tumor volume of 14.6 cm3. After molecular reclassification, 585 were IG-1 (66.4%), 160 IG-2 (18.2%), and 136 IG-3 (15.4%). Benign tumors were concentrated in and around the midline anterior skull base while malignant meningiomas were enriched in the falcine/parasagittal region and the sphenoid wing, similar to the distribution when stratified by chromosome 1p loss. Meningiomas exhibited sharper spatial clustering when stratified by the molecular IG than by WHO grade. WHO grade 2 meningiomas divided equally across IG 1-3, with corresponding partition of spatial distribution in the midline anterior skull base (in WHO grade 2, IG-1) and falcine/parasagittal and sphenoid regions (WHO grade 2, IG-3). Meningioma volumes significantly varied across age, sex, and WHO/IG grades. We demonstrate the utility of voxel-based lesion mapping for intracranial tumors, characterizing distinct meningioma distribution patterns across histopathological and molecularly defined grades. Molecular grading associated with sharper tumor spatial clusters, supporting a phenotype-genotype association in meningiomas.

Craniofacial malignant tumors, their extensions, and surgical strategy for their treatment

Purpose: To identify extension routes of craniofacial malignancies and formulate a surgical treatment plan based thereupon. Material and Methods: We retrospectively reviewed the medical records of 253 patients with craniofacial malignancies who underwent surgical treatment at the Romodanov Neurosurgery Institute from 2002 through 2022. Of the 253 patients, 112 had a primary tumor, and 141, a secondary tumor. Preoperative Karnofsky performance scores ranged from 50 to 70 points. Patients underwent neurological and ophthalmological status assessment, as per routine protocols. Results: Epithelial malignancies were the most common (53.7%), whereas anaplastic meningioma and embryonal malignancies were rather uncommon (1.2% and 0.4%, respectively) craniofacial malignancies. The presence of certain clinical symptoms was associated primarily with tumor origin and extension. A high rate of general brain and rhinological symptoms in our study sample was caused by a high percentage of intracranial and paranasal sinus tumors. Craniofacial malignancies most commonly originate from the midline (particularly, anterior midline skull base). Ethmoidal labyrinth was the most common site of origin (45.0%), followed by a sphenoid sinus (12.2%), pterygopalatine and infratemporal fossae (9.9%), whereas the cavernous sinus and olfactory fossa were the least common sites of origin (0.4% and 1.2%, respectively). Craniofacial tumors extended most commonly intracranially (transdurally, epidurally, via adhesion to the dura mater, and/or cavernous sinus growth) or intraorbitally. Anterior craniofacial resection (bifrontal craniotomy with combined with either lateral rhinotomy or supraorbital advancement; or a subcranial approach) was the most common surgical treatment. Postoperative cerebrospinal fluid rhinorrhea and infectious complications (meningitis and meningoencephalitis) were the most frequent complications. The overall postoperative mortality rate was 2.0%. Conclusion: First, compared to the transcranial and facial approaches, the craniofacial resection is advantageous in terms of the radicality of tumor excision. Second, the subcranial approach is preferable to the bifrontal approach in the presence of marked extracranial tumor component, whereas the transbasal Derome approach is effective in the presence of marked extracranial and/or intracranial tumor components. Finally, both the orbitozygomatic and infratemporal approaches allow for the radicality of excision of lateral skull base malignancies, but the latter approach is associated with a lower rate of complications.

Pterional Approach for Anterior Skull Base Midline Meningiomas against "The More The Merrier" Approach: An Institutional Experience.

Objective Anterior midline skull base meningiomas involving olfactory groove, planum sphenoidale, and tuberculum sellae were usually managed with bifrontal craniotomy until the dawn of advanced microsurgical techniques. With the emergence of microsurgical techniques, midline meningiomas could be tackled solely from a unilateral pterional approach. We present our experience with pterional approach in managing anterior skull base midline meningiomas, including the technical nuances and outcomes. Methods Fifty-nine patients who underwent excision of anterior skull base midline meningiomas through a unilateral pterional craniotomy between 2015 and 2021 were retrospectively analyzed. The surgical technique and patient outcomes in the context of visual, behavioral, olfaction, and quality of life were evaluated during the follow-up. Results A total of 59 consecutive patients were assessed over an average follow-up period of 26.6 months. Twenty-one (35.5%) patients had planum sphenoidale meningioma. Olfactory groove and tuberculum sellae meningioma groups consist of 19 (32%) patients each. Visual disturbance was the predominant symptom with almost 68% of patients presented with it. A total of 55 (93%) patients had complete excision of the tumor with 40 patients (68%) achieving Simpson grade II excision, and 11 (19%) patients had Simpson grade I excision. Among operated cases, 24 patients (40%) had postoperative edema among which 3 (5%) patients had irritability and 1 patient had diffuse edema requiring postoperative ventilation. Only 15 (24.6%) patients had contusion of the frontal lobe and were managed conservatively. Five patients (50%) with seizures had an association with contusion. Sixty-seven percent of patients had improvements in vision and 15% of patients had a stable vision. Only eight (13%) patients had postoperative focal deficits. Ten percent of patients had new-onset anosmia. The average Karnofsky score was improved. Only two patients had recurrence during follow-up. Conclusion A unilateral pterional craniotomy is a versatile approach for the excision of anterior midline skull base meningioma, even for the larger lesions. The ability of this approach in the visualization of posterior neurovascular structures at the earlier stages of surgery while avoiding the opposite frontal lobe retraction and frontal sinus opening makes this approach more preferable over the other approaches.

Endoscopic Anatomical Study of the Glabellar Keyhole Approach.

This study aimed to observe the exposure range of a neuroendoscope through the glabellar approach and measure the anatomical parameters to provide a basis for clinical application. A total of 10 adult cadaveric heads fixed with formalin were dissected by stratified local anatomy and simulated operation. The length of each point was measured from the corresponding anatomical mark of the anterior fossa on the bone window plate and analysed to clarify relevant surgical indications and feasibility to provide an anatomical basis for clinical application. The distance from the lower boundary of the bone window to the left anterior clinoid process was (61.97 ± 3.51) mm, the distance to the right anterior clinoid process was (62.21 ± 3.20) mm, the distance to the leading edge of the optic chiasma was (67.40 ± 5.38) mm, the distance to the sellar tubercle was (57.91 ± 2.64) mm, the distance to the centre of the saddle septum was (68.45 ± 4.88) mm; the distance to the midpoint of the endplate was (67.86 ± 4.91) mm, the distance to the anterior communicating artery was (60.89 ± 6.17) mm, the distance to the left posterior clinoid process was (67.56 ± 3.84) mm, the distance to the right posterior clinoid process was (66.78 ± 3.23) mm, the distance to the bifurcation of the left internal carotid artery was (69.45 ± 2.34) mm and the distance to the bifurcation of the right internal carotid artery was (68.01 ± 3.53) mm. The neuroendoscopic glabellar approach can effectively expose the anatomical structures of the midline anterior skull base and both sides near the sellar area and can be used to look for lesions in the midline anterior skull base.

In Reply: Residual and Recurrent Disease Following Endoscopic Endonasal Approach as a Reflection of Anatomic Limitation for the Resection of Midline Anterior Skull Base Meningiomas.

To the Editor: Drs McGahan, Magill, and Prevedello have provided a very thoughtful and logical algorithm1 for approaching 1 group of tumors discussed in our article.2 Their proposed approach selection for olfactory groove meningiomas demonstrates their experience and skill with all options, which is the ultimate goal of any skull base surgeon. We were glad to see that this article stimulated such a response, as it was written with the hope of clarifying the anatomic boundaries of the endonasal approach as 1 small step in elucidating the “right” approach for any given patient. The authors state that they prefer a “craniotomy” when olfaction is preserved. As they allude, the type of craniotomy may be critical, evidenced by the small series referenced by Jang et al,3 which showed improved olfactory outcomes compared with bifrontal craniotomy in the 21 patients who were selected for frontotemporal craniotomy based largely on unilateral dysfunction and lateral extension. Unspoken in this is that there is inevitably a less radical tumor removal inherent in leaving the cribriform plate (and olfactory fibers) untouched. This must also be considered in the context that the majority of patients with olfactory groove meningiomas have absent or severely impacted olfaction at presentation. For tumors not amenable to endonasal resection, a single-stage resection using a modified subfrontal transbasal approach allows complete tumor resection, including skull base/sinonasal invasion with pericranial flap reconstruction, while minimizing brain manipulation. This approach is mostly extradural with barely any brain exposure. Often, going back to traditional and properly done skull base approaches is the preferred choice. We agree completely with the authors of this letter with respect to the role of olfaction in approach selection for these tumors, but we believe that visual compromise should also be considered, given growing evidence that midline tumors presenting with vision loss may have better outcomes when treated with a midline approach. This is especially important for tuberculum and planum meningiomas, key groups in this article. In addition, neurosurgeons as a group have largely ignored the impact of anterior base meningiomas and surgical approach on neurocognitive outcomes. At a minimum, endonasal approaches minimize radiographic impact on the frontal lobes,3 and further study is needed to understand if there is a cognitive tradeoff for the potential olfactory preservation provided by craniotomy. Indeed, the staged approach discussed in this letter considers this and is an excellent option, especially when there is significant edema. Staging may also occasionally demonstrate an unexpected medial attachment with only pushing borders laterally on the skull base (rather than a true lateral attachment). It is our hope that the conversation that is ongoing via this paper and the resultant letter will continue to help all of us fully understand the impact of various approaches on the multiplicity of critical functions that midline anterior skull base meningiomas involve and how to balance radicality of resection with preservation of these functions. Funding This study did not receive any funding or financial support. Disclosures The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.

Residual and Recurrent Disease Following Endoscopic Endonasal Approach as a Reflection of Anatomic Limitation for the Resection of Midline Anterior Skull Base Meningiomas.

Endoscopic endonasal approaches (EEAs) to anterior skull base meningiomas have grown in popularity, though anatomic limitations remain unclear. To show the anatomic limits of EEA for meningiomas. Retrospective chart review for all patients that underwent EEA for anterior skull base meningiomas from 2005 to 2014. A total of 100 patients averaged follow-up of 46.9 mo (24-100 mo). A total of 35 patients (35%) had olfactory groove, 33 planum sphenoidale (33%), and 32 tuberculum sella (32%) meningiomas. The average diameter was 2.9 cm (0.5-8.1 cm). Vascular encasement was seen in 11 patients (11%) and calcification in 20 (20%). Simpson Grade 1 (SG1) resection was achieved in 64 patients (64%). Only calcification impacted degree of resection (40% SG1, P=.012). The most common residual was on the anterior clinoid dura (11 patients [11%]). Six (6%) had residual superior/lateral to the optic nerve. Residual tumor was adherent to the optic apparatus or arteries in 5 patients (5%) each, and 3 patients (3%) had residual lateral to the mid-orbit. Rates of residual decreased over time. A total of 11 patients (11%) had tumor recurrence (mean of 40 mo): 4 (4%) on the anterior clinoid, 2 (2%) each on the lateral orbital roof, adherent to optic apparatus and superolateral to the optic nerve, and 1 (1%) was at the anterior falx. Anterior skull base meningiomas can effectively be approached via EEA in most patients; tumors extending to the anterior clinoid, anterior falx, or superolateral to the optic nerve or orbital roof, especially if calcified, may be difficult to reach via EEA.

Extended endonasal endoscopic approach for anterior midline skull base lesions

AimIn recent years, extended endoscopic endonasal approach (EEEA) has been used as an alternative to transcranial approaches in the treatment of anterior midline skull base lesions. We retrospectively reviewed our cases operated using this technique and compared the results with current literature. MethodThe data of 24 patients who were operated using EEEA in our department between 2010–2018 were retrospectively analyzed. The lesions were located in the midline between the posterior wall of the frontal sinus and tuberculum sella. Tumor locations, histopathological diagnoses, surgical techniques, outcomes and complications were documented. ResultsEleven patients were female and 13 were male. Their ages ranged between 18–75 years (mean 40.5 years). Considering their locations; 12 were in the anterior fossa (50 %), 7 were in the tuberculum sella (29.1 %), and 5 were in both anatomic sites (20.8 %). Histopathologically, our series consisted of 15 meningiomas, 6 osteomas, 2 dermoid tumors and 1 metastatic carcinoma. We achieved gross total resection in 75 % of our patients. Ten patients presented with visual complaints and 7 of them improved postoperatively. Postoperative cerebrospinal fluid leakage (CSF) was observed in 3 patients and one of them developed meningitis and subsequently died of sepsis. ConclusionAlthough the number of cases is low, EEEA seems like a safe, effective and well-tolerated treatment modality for anterior midline skull base lesions. But strict preventive measures should be taken for a possible CSF leak.

The extended pterional approach for midline anterior skull base meningiomas

Background: Various surgical approaches for the management of midline anterior skull base meningiomas exist in the literature. The main surgeon target is proper selection the appropriate approach that achieves total removal of the lesion without causing morbidity or mortality and facilitates safe effective removal of the tumour.
 Objectives: To evaluate the role of the extended pterional approach for excision of midline anterior skull base meningiomas as regarding the effectiveness, extent of resection and surgical outcome.
 Patients and methods: This retrospective study involved 23 cases with midline anterior skull base meningiomas resected through the extended pterional approach. Patients' clinical data, operative notes, imaging studies and clinical follow-up data were analyzed and evaluated.
 Results: Tumors studied were 9 olfactory groove meningiomas, 8 tuberculum Sellae meningiomas, 4 planum sphenoidale meningiomas and 2 diaphragma sellae meningiomas. Gross total resection tumour excision in 15 cases (64.5%), subtotal excision in 5 cases (21.5%) and partial excision in 3 cases (14%). Complications were diabetes insipidus (2 cases 8.6%), CSF rhinorrhea (3 cases 12.9%) and visual deterioration (3 cases 12.9%). We had two cases of mortality.
 Conclusion: The extended pterional approach allows safe and effective removal of midline anterior skull base meningiomas. It expands the exposure offered by the classic pterional approach and minimizing the necessity for applying fixed brain retraction with good cosmetic outcome and less approach-related morbidities in comparison with the extensive skull base approaches.

Surgical challenges and outcome of endoscopic endonasal approaches in the management of recurrent pituitary adenomas

Background: Various surgical approaches for the management of midline anterior skull base meningiomas exist in the literature. The main surgeon target is proper selection the appropriate approach that achieves total removal of the lesion without causing morbidity or mortality and facilitates safe effective removal of the tumor.
 Objectives: To evaluate the role of the extended pterional approach for excision of midline anterior skull base meningiomas as regard the effectiveness, extent of resection and surgical outcome.
 Patients and methods: This retrospective study involved 23 cases with midline anterior skull base meningiomas resected through the extended pterional approach. Patients' clinical data, operative notes, imaging studies and clinical follow-up data were analyzed and evaluated.
 Results: Tumors studied were 9 olfactory groove meningiomas, 8 tuberculum Sellae meningiomas, 4 planum sphenoidale meningiomas and 2 diaphragma sellae meningiomas. Gross total resection tumor excision in 15 cases (64.5%), subtotal excision in 5 cases (21.5%) and partial excision in 3 cases (14%). Complications were diabetes insipidus (2 cases 8.6%), CSF rhinorrhea (3 cases 12.9%) and visual deterioration (3 cases 12.9%). We had two cases of mortality.
 Conclusion: The extended pterional approach allows safe and effective removal of midline anterior skull base meningiomas. It expands the exposure offered by the classic pterional approach and minimizing the necessity for applying fixed brain retraction with good cosmetic outcome and less approach related morbidities in comparison with the extensive skull base approaches.

Microsurgical Anatomy Review of Bifrontal Limited Transbasal Approach – Quantitative and Anatomy Study

The bifrontal transbasal approach is an anterior midline skull base approach to anterior skull base, sellae region and, if needed, to posterior skull base in the midline, often used for tumoral lesions but also useful for vascular or infectious pathologies. Descriptive anatomic study, 5 formalin-fixed human cadaveric heads were used injected with colored silicone. The dissection was made step-by-step to describe every anatomic structure encountered. The working distance was obtained from the posterior wall of the frontal sinus with and without orbital rim to the pituitary stalk, the sellae, the pontomedullary sulcus, and the anterior margin of the foramen magnum. Stepwise anatomic dissection was performed dividing the surgical technique into 6 stages: soft-tissue stage, bone stage, sinus stage, clival stage, intradural, and measurements. The objective of making the supraorbital osteotomy was to improve the vision over the neural structures without brain retraction and limited to the midline supraorbital rim to avoid aggressive manipulation and injury to the orbit. The working distances measured with the orbital rim were on average: to the pituitary stalk, 70.5 mm; to the sellae, 81.3 mm; to the pontomedullary sulcus, 97 mm; and the foramen magnum, 99.5 mm. Without the orbital rim measures were: to the pituitary stalk, 57 mm; to the sellae, 62.5 mm; to the pontomedullary sulcus, 96 mm; and the foramen magnum, 98.5 mm. The addition of osteotomies including removing of the orbital rim improves the access to the central skull base with special benefits on the working distances to the sellae region.

Transglabellar approach for surgical management of unruptured anterior cerebral artery aneurysms: A set of 8 patients

ObjectivesUnruptured anterior cerebral artery aneurysms (ACAA) management is not standardized, since the decision to intervene can lead to unnecessary surgical aftermaths. One of the key issues could be to decrease the surgical consequences. We describe herein an original minimally invasive transglabellar approach in the management of ACAA. Patients and MethodsWe report our experience with the transglabellar approach which is used for two years in our centre. With an inter-eyebrow skin incision, a trans sinusal approach gives direct access to the anterior midline skull base. Aneurysm clipping is carried out. The closure requires obstruction of nasofrontal ducts and sinus mucosa removal. ResultsWe operated 8 patients using this approach. The aneurysms were clipped successfully in every case.One case of cerebrospinal fluid leak and two cases of superficial infection were observed. All the patients were satisfied with the aesthetic results. ConclusionThe transglabellar approach is an effective, safe and minimally invasive procedure for the treatment of ACAA.

Proximal Branches of the Anterior Cerebral Artery: Anatomic Study and Applications to Endoscopic Endonasal Surgery.

The endoscopic endonasal approach is a surgical alternative for midline anterior skull base tumors. A detailed understanding of the proximal anterior cerebral artery (ACA) branches' anatomy from an endonasal perspective is essential for avoiding vascular complications. To evaluate, from an endonasal perspective, the anatomic variations of the ACA and its proximal branches, specifically the recurrent artery of Heubner (RAH), and the fronto-orbital (FOA) and frontopolar (FPA) arteries. We study the origin, course, branching pattern, diameter, and relationship between the proximal ACA branches and the optic apparatus and olfactory tract in 25 head specimens. The RAH was present in all hemispheres and originated within 3±1.5 mm of the AcomA, with a 0.4±0.1 mm diameter. Based on its relationship with the A1 segment, we observed three RAH courses: anterior (40%), superior (22%), and posterior (38%). The FOA was present in all cases, a mean of 6±4 mm from the AcomA, with a 0.7±0.4 mm diameter. The FOA arose mainly from the A2 (70%), with three courses in relation to the olfactory tract: crossing its proximal third (54%), crossing its middle third (31%), and running parallel to it along the gyrus rectus (15%). The FPA was present in 92% of the hemispheres, a mean of 10±5 mm from the AcomA, always arising from the A2 and coursing anteriorly within the interhemispheric fissure towards the frontal pole. The RAH, FOA, and FPA can be differentiated by origin, course, and destination using the A1 segment, olfactory tract, and interhemispheric fissure, respectively, as surgical landmarks.

Preservation of olfaction in anterior midline skull base meningiomas: a comprehensive approach.

Olfaction is an undervalued sense in neurosurgery. Attempted surgical resection of anterior cranial fossa meningiomas puts the olfactory pathway at risk. Preservation of olfaction may increase the postoperative quality of life. Objective assessment of olfaction may inform clinical decision-making and influence the selection of operative approaches for surgical resection. We reviewed all patients who underwent surgical resection for midline anterior skull base meningiomas from July 1, 2014, through December 31, 2017. Patient demographics, tumor size, operative approach, pre- and postoperative deficits, and Simpson grade were collected and analyzed. Postoperative olfaction was assessed by clinical evaluation as well as objective evaluation using the University of Pennsylvania Smell Identification Test (UPSIT). Twenty-eight patients (10 male, 18 female) were included with an average age of 53.8years (range 27-80years). Twenty-six patients underwent craniotomy for resection, while 2 patients had endoscopic approaches. Average tumor volume was 402.1cm3 (6.6-2507.7cm3). Preoperatively, five patients (17.8%) presented with olfactory impairment. Objectively, 50% of patients (14/28) consented and completed the UPSIT. The average postoperative UPSIT score was 25.8/40 (9/40-38/40). Two patients not identified on clinical assessment alone demonstrated postoperative olfactory deficit on UPSIT (2/14). There are limited published studies evaluating olfaction in patients who undergo skull-based approaches for anterior fossa meningiomas. Our series showed the highest olfaction preservation rate (87.5%) using a comprehensive strategy and multitude of surgical approaches based on the olfactory function and tumor characteristics.

Small Extended Bifrontal Approach for Midline Anterior Skull Base Meningiomas: Our Experience with 54 Consecutive Patients

To describe the technique of a small extended bifrontal approach and review the clinical outcome of patients with midline anterior skull base (MASB) meningiomas treated using this technique. The small extended bifrontal craniotomy extends inferiorly to the nasofrontal suture without entering the orbit, superiorly 3 cm above the supraorbital rim, and laterally 3 cm to the midline on both sides. A review of a prospectively acquired database was performed of 54 consecutive patients with MASB meningiomas who underwent this craniotomy. Twenty-nine patients with olfactory groove meningiomas, 2 with planum sphenoidale meningiomas (PSMs), and 23 with tuberculum sellae meningiomas (TSMs) were treated using this technique. Gross total resection was achieved in all patients. Of 29 patients with olfactory groove meningiomas, 12 (41.4%) had normal olfaction at presentation and 8 had preservation of olfaction postoperatively. Of 25 patients with TSMs/PSMs, 23 (92.0%) had preoperative visual impairment, with 13 showing improved vision (56.5%), 8 unchanging (34.8%), and 2 deteriorating (8.7%) after surgery. The most common complications were anosmia and hyposmia, which occurred in 5 patients (20.0%) and 3 patients (12.0%) with TSMs/PSMs, respectively. No mortality was reported. There was no recurrence in all patients after a mean follow-up of 39.5 months (range, 16-64 months). The small extended bifrontal approach is a safe and effective technique for resection of MASB meningiomas, which provides adequate surgical exposure with less approach-related morbidity. It is an excellent alternative for surgeons who favor the bifrontal approach and its extended variations.

Extent of surgery in endoscopic transsphenoidal skull base approaches and the effects on sinonasal morbidity.

Endoscopic transsphenoidal skull base surgery (ETSS) is now considered the criterion standard approach for resection of pituitary adenomas and other midline anterior skull base lesions. Normal sinonasal structures are resected during ETSS, which raises concerns for nasal morbidity and patient-based outcome. To perform a surgical outcome assessment by examining whether the extent of ETSS approaches affected patient-specific sinonasal quality of life as measured by the 22-item Sino-Nasal Outcome Test (SNOT-22). A single-center prospective cohort study of patients operated on by the same skull base team between 2012 and 2016. Patients with completed pre- and postoperative SNOT-22 were included. The primary outcome was SNOT-22 scores at preoperative, 0-1 month, 2-4 months, >5 months follow-up. Age, sex, tumor pathology, surgical procedure, and intraoperative cerebral spinal fluid leak repair were also obtained. Of the 249 ETSS performed, 148 patients (59%) had at least one completed SNOT-22; 45 (18%) met the inclusion criteria. Sinonasal quality of life based on SNOT-22 at the 0-1-month follow-up was significantly worse than the presurgical levels (p < 0.05). However, there was a return of SNOT-22 scores to preoperative levels at 2-4 months (p > 0.05), which was sustained at >5 months (p > 0.05). Factors such as the extent of ETSS, a previous nasal surgery, repair of an intraoperative cerebral spinal fluid leak, and the tumor pathology did not affect SNOT-22 scores at any follow-up intervals (p > 0.05). Sinonasal quality of life worsened after ETSS at 0-1 month follow-up but returned to preoperative levels at 2-4 months and remained at postoperative levels >5 months. Analysis of these data will allow us to educate our patients that the anticipated nasal morbidity after ETSS is usually only transient and should be expected to recover to preoperative levels.

Residual and Recurrent Disease after Endoscopic Endonasal Approach to Midline Anterior Skull Base Meningiomas

Residual and Recurrent Disease after Endoscopic Endonasal Approach to Midline Anterior Skull Base Meningiomas

Nonrandom spatial clustering of spontaneous anterior fossa cerebrospinal fluid fistulas and predilection for the posterior cribriform plate.

OBJECTIVE The anterior skull base is a common site for the spontaneous development of meningoceles, encephaloceles, and meningoencephaloceles that can lead to cerebrospinal fluid (CSF) fistula formation, particularly in association with idiopathic intracranial hypertension. In some circumstances the lesions are difficult to localize. Whether all sites in the anterior skull base are equally prone to fistula formation or whether they are distributed randomly throughout the anterior skull base is unknown, although the anterior cribriform plate has been proposed as the most frequent location. The purpose of this study was to identify sites of predilection in order to provide assistance for clinicians in finding occult leaks and increase the understanding of the etiology of this pathology. METHODS The authors performed a retrospective review of a prospectively acquired surgical database of all endonasal endoscopic surgeries performed at Weill Cornell Medical College by the senior authors. Spontaneous CSF fistulas of the anterior skull base were identified. The anatomical sites of the defects were located on radiographic images and normalized to a theoretical 4 × 2 grid representing the anterior midline skull base. Data from the left and right skull base were combined to increase statistical power. This grid was then used to analyze the distribution of defects. Frequency analysis was performed by means of a chi-square test, with a subsequent Monte Carlo simulation to further strengthen the statistical support of the conclusions. RESULTS Nineteen cases of spontaneous CSF fistulas were identified. Frequency analysis using chi-square indicated a nonrandom distribution of sites (p = 0.035). Monte Carlo simulation supported this conclusion (p = 0.034). Seventy-four percent of cases occurred in the cribriform plate (p = 0.086). Moreover, 37% of all defects occurred in the posterior third of the cribriform plate. CONCLUSIONS Anterior skull base spontaneous CSF leaks are distributed in a nonrandom fashion. The most likely site of origin of the spontaneous CSF leaks of the anterior midline skull base is the cribriform plate, particularly the posterior third of the plate, likely because of the lack of significant thick bony buttressing. Clinicians searching for occult spontaneous leaks of the anterior skull base should examine the cribriform plate, especially the posterior third with particularly close scrutiny.

Endoscopic skull base surgery: evaluation of current clinical outcomes.

Endoscopic skull base surgery is one of the most recent fields of neurosurgery. Successive innovations were developed throughout history so that the current concepts that rule this surgical field could be reached. The current paper presents the evolution of endoscopic surgery and its current results on the treatment of skull base tumor, based on a review of meta-analysis and clinical series. A PubMed search for articles published between January 1990 and January 2014 about "endoscopic skull base surgery", "endoscopic transsphenoidal approach", "endoscopic treatment of parasellar tumors" and "suprasellar lesions" was performed. According to the current data, endoscopic surgery seems to be superior to open and transsphenoidal microscopic removal of giant pituitary adenomas. Endoscopy is at least as successful as transsphenoidal microsurgery for the removal of pituitary adenomas and craniopharyngiomas. Transcranial open approaches, in the context of anterior midline skull base meningiomas, present higher rates of gross total resection, fewer complications and better clinical results than endoscopy approaches. The rate of postoperative CSF leakage has been significantly reduced with the introduction of new techniques such as the Hadad-Bassagasteguy flap but still represent one of the most important complications of this technique. Currently, selected tumors located at the anterior, middle and posterior fossa can be adequately assessed using the endoscope with low rates of postoperative CSF leaks. Endoscopic surgery has substantially evolved in the last decades through the collaboration of different teams around the world. The endoscope is now an essential tool in the neurosurgery armamentarium with great potential for new applications in the nearby future.

Surgical Anatomy for Control of Ethmoidal Arteries During Extended Endoscopic Endonasal or Microsurgical Resection of Vascular Anterior Skull Base Meningiomas

eningiomas represent about 13%e20% of brain tumors; skull base meningiomas represent about 44%. M Anterior skull base meningiomas are supplied from anterior or posterior ethmoidal arteries (branches of the ophthalmic artery), as in olfactory groove (10%) and tuberculum sellae and planum sphenoidale (13%) meningiomas, or middle meningeal arteries, as in sphenoid ridge meningiomas 17% (9, 13, 23). In addition to anastomosis between the middle meningeal artery and the ophthalmic artery, the middle meningeal artery may arise from the ophthalmic artery, or the ophthalmic artery may arise from the middle meningeal artery in rare cases (11, 12, 15, 33). Collaterals from the meningeal branches of the internal carotid arteries, frontal or sphenoid branches of the middle meningeal arteries, and the sphenopalatine branch of the distal maxillary artery may share in the secondary arterial supply of midline anterior skull base meningiomas (olfactory groove, planum sphenoidale, and tuberculum sellae). This rich arterial network predisposes anterior skull base lesions to high vascularity in many cases, especially meningiomas and arteriovenous malformations.

Open Transcranial Resection of Small (

Despite technical surgical advance, the ultimate management of midline anterior skull base meningiomas remains to be defined. Open transcranial surgery is usually the first treatment option for large meningiomas, while less invasive techniques such as endoscopic surgery or radiosurgery might represent an alternative to open microsurgery for smaller lesions. The aim of our study is to investigate the outcome of open transcranial microsurgery in the resection of small (<35 mm) meningiomas of the midline anterior cranial base. Clinical and surgical data from 43 patients affected by small midline anterior skull base meningiomas operated via an open transcranial approach were retrospectively reviewed. The tumor diameter on its major axis ranged from 12 to 35 mm, with a mean diameter of 28 mm. Gross total resection (Simpson grades I-II) was achieved in 100% of cases through a pterional approach. Postoperative overall morbidity was 9%. It was 3% among patients <70 years. No mortality was reported. Postoperative visual outcome was significantly associated with preoperative visual performance (P = 0.02), but not with preoperative optic nerve compression as detected by magnetic resonance imaging (P = 0.116). Age >70 years was associated with postoperative visual impairment, although not significantly (P = 0.06). Visual function was preserved or improved in 95% of cases, in 100% of patients <70 years, and in 71% of patients with preoperative visual impairment. In our experience, open transcranial surgery proved safe and effective for midline anterior skull base meningiomas smaller than 35 mm in all patients <70 years and in patients >70 years without preoperative visual deficit. Our data are consistent with the literature. Conversely, the standard of treatment for the subgroup of patients >70 years with preoperative visual deficit has not yet been defined. This specific subgroup of patients offers a topic for further investigation.