Stereotactic radiosurgery in the management of skull base chordomas: a comprehensive systematic review and meta-analysis.

OBJECTIVE: Chordoma is a primary bone tumor with limited literature on its management because of its rarity. Resection, while considered the first-line treatment, does not always provide adequate tumor control. In this systematic review, the authors aimed to provide comprehensive insights by managing these tumors with stereotactic radiosurgery (SRS). METHODS: A systematic review was conducted according to PRISMA guidelines using the PubMed, Scopus, Web of Science, Embase, and Cochrane Library databases. Search terms included chordoma and radiosurgery and their equivalent terms. Data on baseline characteristics, SRS details, and outcomes were extracted. The Joanna Briggs Institute checklist was used to assess risk of bias. A meta-analysis was performed on relevant variables. RESULTS: A total of 33 eligible studies encompassing 714 patients with skull base chordomas were included. Most studies had a low risk of bias. Patients, predominantly male (57.37%) with a mean age of 46.54 years, exhibited a conventional chordoma subtype (74.77%) and primary lesions (77.91%), mainly in the clivus (98.04%). The mean lesion volume was 13.49 cm3, and 96.68% of patients had undergone prior surgical attempts. Gamma Knife radiosurgery (88.76%) was the predominant SRS method. Radiologically, 27.19% of patients experienced tumor regression, while 55.02% showed no signs of disease progression at the latest follow-up. Progression occurred after a mean of 48.02 months. Symptom improvement was noted in 27.98% of patients. Radiosurgery was associated with a relatively low overall adverse event rate (11.94%), mainly cranial nerve deficits (8.72%). Meta-regression revealed that age and primary lesion type influenced symptom improvement, while factors like extent of resection, radiotherapy, and SRS type affected adverse event rates. CONCLUSIONS: This systematic review provides evidence on the safety and effectiveness of radiosurgery in the management of skull base chordomas. Local tumor control was achieved in the majority of patients treated with SRS. Various baseline characteristics and SRS features have been analyzed to identify modifying factors for each outcome to provide a framework for informed decision-making when managing these patients.

Supramarginal resection of skull base chordomas: proof of concept and preliminary outcomes.

OBJECTIVE: The mainstay of treatment for skull base chordoma (SBC) is maximal safe resection followed by radiotherapy. However, even after gross-total resection (GTR), the recurrence rate is high due to microscopic disease in the resection margins. Therefore, supramarginal resection (SMR) could be beneficial, as has been shown for sacral chordoma. The paradigm of postoperative radiation therapy for every patient has also begun to change, as molecular profiling has shown variability in the risk of recurrence. The aim of this study was to present the concept of SMR applied to SBC, along with an individualized decision for postoperative radiation therapy. METHODS: This is a retrospective analysis of all SBCs operated on by the senior author between 2018 and 2023. SMR was defined as negative histological margins of bone and/or dura mater, along with evidence of bone resection beyond the tumor margins in the craniocaudal and lateral planes on postoperative imaging. Tumors were classified into 3 molecular recurrence risk groups (group A, low risk; group B, intermediate risk; and group C, high risk). Postoperative radiation therapy was indicated in group C tumors, in group B chordomas without SMR, or in cases of patient preference. RESULTS: Twenty-two cases of SBC fulfilled the inclusion criteria. SMR was achieved in 12 (55%) cases, with a mean (range) amount of bone resection beyond the tumor margins of 10 (2-20) mm (+40%) in the craniocaudal axis and 6 (1-15) mm (+31%) in the lateral plane. GTR and near-total resection were each achieved in 5 (23%) cases. Three (19%) tumors were classified as group A, 12 (75%) as group B, and 1 (6%) as group C. Although nonsignificant due to the small sample size, the trends showed that patients in the SMR group had smaller tumor volumes (13.9 vs 19.6 cm3, p = 0.35), fewer previous treatments (33% vs 60% of patients, p = 0.39), and less use of postoperative radiotherapy (25% vs 60%, p = 0.19) compared to patients in the non-SMR group. There were no significant differences in postoperative CSF leak (0% vs 10%, p = 0.45), persistent cranial nerve palsy (8% vs 20%, p = 0.57), and tumor recurrence (8% vs 10%, p = 0.99; mean follow-up 15 months) rates between the SMR and non-SMR groups. CONCLUSIONS: In select cases, SMR of SBC appears to be feasible and safe. Larger cohorts and longer follow-up evaluations are necessary to explore the benefit of SMR and individualized postoperative radiation therapy on progression-free survival.

Anatomical determinants of occipitocervical fusion in skull base chordoma resection: a systematic review of the literature with illustrative cases.

OBJECTIVE: Skull base chordomas are rare, locally osseo-destructive lesions that present unique surgical challenges due to their involvement of critical neurovascular and bony structures at the craniovertebral junction (CVJ). Radical cytoreductive surgery improves survival but also carries significant morbidity, including the potential for occipitocervical (OC) destabilization requiring instrumented fusion. The published experience on OC fusion after CVJ chordoma resection is limited, and the anatomical predictors of OC instability in this context remain unclear. METHODS: PubMed and Embase were systematically searched according to the PRISMA guidelines for studies describing skull base chordoma resection and OC fusion. The search strategy was predefined in the authors' PROSPERO protocol (CRD42024496158). RESULTS: The systematic review identified 11 surgical case series describing 209 skull base chordoma patients and 116 (55.5%) who underwent OC instrumented fusion. Most patients underwent lateral approaches (n = 82) for chordoma resection, followed by midline (n = 48) and combined (n = 6) approaches. OC fusion was most often performed as a second-stage procedure (n = 53), followed by single-stage resection and fusion (n = 38). The degree of occipital condyle resection associated with OC fusion was described in 9 studies: total unilateral condylectomy reliably predicted OC fusion regardless of surgical approach. After lateral transcranial approaches, 4 studies cited at least 50%-70% unilateral condylectomy as necessitating OC fusion. After midline approaches-most frequently the endoscopic endonasal approach (EEA)-at least 75% unilateral condylectomy (or 50% bilateral condylectomy) led to OC fusion. Additionally, resection of the medial atlantoaxial joint elements (the C1 anterior arch and tip of the dens), usually via EEA, reliably necessitated OC fusion. Two illustrative cases are subsequently presented, further exemplifying how the extent of CVJ bony elements removed via EEA to achieve complete chordoma resection predicts the need for OC fusion. CONCLUSIONS: Unilateral total condylectomy, 50% bilateral condylectomy, and resection of the medial atlantoaxial joint elements were the most frequently described independent predictors of OC fusion in skull base chordoma resection. Additionally, consistent with the occipital condyle harboring a significantly thicker joint capsule at its posterolateral aspect, an anterior midline approach seems to tolerate a greater degree of condylar resection (75%) than a lateral transcranial approach (50%-70%) prior to generating OC instability.

A watch, wait, and rescan approach for incidental benign-appearing notochordal lesions of the skull base.

OBJECTIVE: The aim of this study was to describe the natural history of incidental benign-appearing notochordal lesions of the skull base with specific attention to features that can make differentiation from low-grade chordoma more difficult, namely contrast uptake and bone erosion. METHODS: In this retrospective case series, the authors describe the clinical outcomes of 58 patients with incidental benign-appearing notochordal lesions of the clivus, including those with minor radiological features of bone erosion or contrast uptake. RESULTS: All lesions remained stable during a median follow-up of almost 3 years. Thirty-seven (64%) patients underwent contrast-enhanced MRI; lesions in 14 (38%) of these patients exhibited minimal contrast enhancement. Twenty-seven (47%) patients underwent CT; lesions in 6 (22%) of these patients exhibited minimal bone erosion. CONCLUSIONS: These data make the case for monitoring selected cases of benign-appearing notochordal lesions of the clivus in the first instance even when there is minor contrast uptake or minimal bone erosion.

Jugular Foramen Paragangliomas.

Paragangliomas are the most common tumors at jugular foramen and pose a great surgical challenge. Careful clinical history and physical examination must be performed to adequately evaluate neurological deficits and its chronologic evolution, also to delineate an overview of the patient performance status. Complete imaging evaluation including MRI and CT scans should be performed, and angiography is a must to depict tumor blood supply and sigmoid sinus/internal jugular vein patency. Screening for multifocal paragangliomas is advisable, with a whole-body imaging. Laboratory investigation of endocrine function of the tumor is necessary, and adrenergic tumors may be associated with synchronous lesions. Preoperative prepare with alpha-blockage is advisable in norepinephrine/epinephrine-secreting tumors; however, it is not advisable in exclusively dopamine-secreting neoplasms. Best surgical candidates are young otherwise healthy patients with smaller lesions; however, treatment should be individualized each case. Variations of infratemporal fossa approach are employed depending on extensions of the mass. Regarding facial nerve management, we avoid to expose or reroute it if there is preoperative function preservation and prefer to work around facial canal in way of a fallopian bridge technique. If there is preoperative facial nerve compromise, the mastoid segment of the nerve is exposed, and it may be grafted if invaded or just decompressed. A key point is to preserve the anteromedial wall of internal jugular vein if there is preoperative preservation of lower cranial nerves. Careful multilayer closure is essential to avoid at most cerebrospinal fluid leakage. Residual tumors may be reoperated if growing and presenting mass effect or be candidate for adjuvant stereotactic radiosurgery.

Microsurgical resection of a large petroclival meningioma through an extended retrosigmoid approach: how I do it.

BACKGROUND: Petroclival meningiomas are challenging tumors. Several skull base approaches have been proposed in the last decades, with variable rates of postoperative morbidity and extent of resection. METHODS: We herein reported the step-by-step microsurgical resection of a large petroclival meningioma through an extended retrosigmoid approach. Detailed surgical technique has been accompanied by a 2D operative video. CONCLUSION: The extended retrosigmoid approach allowed for a safe gross total resection of the tumor, as confirmed by the postoperative MRI. The patient did not experience any new postoperative deficit, despite a transient diplopia, and was discharged on postoperative day 7.

The trans-sylvian trans-petrosal "half & half" approach-a how I do it.

BACKGROUND: Petroclival meningiomas are one of the most challenging tumors to be operated in the realm of neurosurgery. Many approaches have been developed over the years. METHOD: The authors describe the Half & Half (H&H) approach whose main indication is petroclival meningiomas with suprasellar extension. The part of the tumor located above CN III and in the retrochiasmatic space is addressed through a trans-sylvian, while the petroclival portion is through an extradural anterior petrosectomy approach. The wide surgical corridor given by this approach allows extensive tumor resection while avoiding the risk associated with the manipulation of intracavernous neurovascular structures. CONCLUSION: The H&H approach is an effective strategy to maximize the safe resection of petroclival meningiomas.

Phantom study of a fully automatic radioactive seed placement robot for the treatment of skull base tumours.

BACKGROUND: Interstitial brachytherapy is a form of intensive local irradiation that facilitates the effective protection of surrounding structures and the preservation of organ functions, resulting in a favourable therapeutic response. As surgical robots can perform needle placement with a high level of accuracy, our team developed a fully automatic radioactive seed placement robot, and this study aimed to evaluate the accuracy and feasibility of fully automatic radioactive seed placement for the treatment of tumours in the skull base. METHODS: A fully automatic radioactive seed placement robot was established, and 4 phantoms of skull base tumours were built for experimental validation. All the phantoms were subjected to computed tomography (CT) scans. Then, the CT data were imported into the Remebot software to design the preoperative seed placement plan. After the phantoms were fixed in place, navigation registration of the Remebot was carried out, and the automatic seed placement device was controlled to complete the needle insertion and particle placement operations. After all of the seeds were implanted in the 4 phantoms, postoperative image scanning was performed, and the results were verified via image fusion. RESULTS: A total of 120 seeds were implanted in 4 phantoms. The average error of seed placement was (2.51 ± 1.44) mm. CONCLUSION: This study presents an innovative, fully automated radioactive particle implantation system utilizing the Remebot device, which can successfully complete automated localization, needle insertion, and radioactive particle implantation procedures for skull base tumours. The phantom experiments showed the robotic system to be reliable, stable, efficient and safe. However, further research on the needle-soft tissue interaction and deformation mechanism of needle puncture is still needed.

[Preoperative Simulation of Endoscopic Endonasal Approach for Craniopharyngiomas or Tuberculum Sellae Meningiomas].

Preoperative simulation for endoscopic endonasal approach(EEA)using computed tomography and magnetic resonance imaging evaluates tumor extension and the relationship between adjacent structure(the pituitary stalk, major vessels, and cranial nerves); therefore, preoperative planning of nasal procedure, skull base bony removal, and cranial base reconstruction are possible. Additionally, three-dimensional(3D)fusion image aids surgeons to visualize intraoperative 3D findings. These preoperative simulations are critical to avoid complications and predict pitfalls perioperatively. However, tumor consistency or adhesion with adjacent structure cannot be predicted but is judged perioperatively, which affects the extent of tumor resection. This manuscript describes important points of preoperative simulation for EEA, especially the transplanum-transtuberculum approach for craniopharyngiomas or tuberculum sellae meningiomas, showing some examples in patients.

[Endoscopic transnasal resection of clival meningiomas]. / Rezul'taty endoskopicheskogo transnazal'nogo udaleniya meningiom oblasti skata.

BACKGROUND: Surgical treatment of ventral and ventrolateral meningiomas of posterior cranial fossa is difficult in modern neurosurgery. This is due to peculiarities of approach to these areas and concentration of critical structures (cranial nerves and great vessels). Currently, endoscopic transnasal approach to these meningiomas allows partial, and in some cases, total resection. However, this technique is not widespread. OBJECTIVE: To analyze the world literature data on postoperative outcomes in patients with clival and petroclival meningiomas after endoscopic transnasal resection. MATERIAL AND METHODS: We analyzed 22 articles representing treatment of 61 patients with clival and petroclival meningiomas. RESULTS: Total or near-total resection was achieved in 22.9% of cases, subtotal resection - 40.9%, partial resection - 26.2% (data were not provided in other cases). Even partial and subtotal resection leads to significant regression of symptoms. CONCLUSION: Endoscopic transnasal surgery is a full-fledged alternative to transcranial approaches in surgical treatment of clival meningiomas. It is also an additional option for patients with petroclival meningiomas after ineffective transcranial approaches. Transnasal tumor shrinkage and devascularization lead to brainstem decompression, regression of hydrocephalus and baseline clinical symptoms.

Endoscopic endonasal approach for olfactory groove meningioma resection: Strategies and outcomes in a retrospective case series.

OBJECTIVE: Though the endoscopic endonasal approach (EEA) is a widely accepted treatment for skull base tumors, the specific use of EEA for olfactory groove meningiomas (OGMs) is debated, with variable outcomes reported in the literature. We review the surgical results of OGM resections for one surgeon including the operative approach, surgical nuances, and outcomes, with a focus on factors relating to patient selection which favor EEA over transcranial approaches. METHODS: We retrospectively reviewed thirteen cases of endoscopic endonasal resection of olfactory groove meningiomas. Patient characteristics, clinical characteristics, surgical outcomes, and complications were analyzed. Extent of resection was determined based on volumetric analysis of pre- and postoperative MRI. RESULTS: Anatomic characteristics that render a tumor difficult to access fully are lateral extension beyond the mid-orbit and anterior extension to the falx. Simpson Grade I resection was achieved in 11/13 (84.6 %) cases. Mean pre-operative tumor volume was 8.99 cm3 (range 2.19-16.79 cm3), and 92 % of tumors were WHO grade I. We demonstrate 2 cases of smell preservation, possible with small unilateral tumors and tumors that are confined to either the anterior or posterior portion of the cribriform plate. The post-operative CSF leak rate was 7.7 %, without prophylactic lumbar CSF drainage. The mortality rate was 7.7 % (n = 1) after infectious complications following CSF leak. CONCLUSIONS: Endoscopic endonasal resection of olfactory groove meningiomas is an effective and safe operative method with outcomes and complication rates comparable to transcranial approaches. Key considerations include careful patient selection and familiarity with technical nuances of endoscopic endonasal approach for this specific tumor type.

The Displacement Patterns of Petrous Internal Carotid Artery and Its Morphometric Relations with Vidian Canal in Petroclival Chondrosarcomas Relevant to Extended Endoscopic Endonasal Approaches: A Radiological Study.

BACKGROUND: Extended endoscopic endonasal approaches (EEAs) to petroclival chondrosarcomas (PCs) require a thorough understanding of skullbase anatomy, especially the anatomy of petrous internal carotid artery (pICA), as ICA injury is the most dreaded complication of extended EEAs. We conducted this study to determine the displacement patterns of pICA in patients with PCs. METHODS: Contrast enhanced computed tomography scan and angiography images of patients with PCs were analyzed for following parameters-antero-posterior, cranio-caudal, medio-lateral, and direct distances between anterior genu of petrous internal carotid artery (AGpICA) and posterior end of Vidian canal (pVC). pICA encasement/narrowing by tumor was noted on magnetic resonance imaging. RESULTS: We studied 11 patients with histopathologically proven PCs. pICA encasement/narrowing and pVC destruction were observed in one patient each. The mean antero-posterior and cranio-caudal distances on tumor side/normal side were 7.7 ± 1.9/6.4 ± 1.0 mm & 4.5 ± 1.5/3.4 ± 0.9 mm, respectively. The overall displacement was posterior & superior. Medio-lateral displacement was seen in 4 patients (lateral in 3 and medial in 1). In rest, AGpICA was centered on pVC. The mean direct distance was 9.4 ± 2.5 mm. In 3 patients with displacement seen in all three axes, direct distance was measured by the "cuboid method." Overall, posterior-superior-lateral, posterior-superior, and anterior-inferior were the common displacement patterns of AGpICA relative to pVC. CONCLUSIONS: The displacement patterns of AGpICA in PCs are variable. An individualized approach with meticulous analysis of preoperative imaging can help in determining the relation between AGpICA and pVC. This detailed morphometric information can facilitate better orientation to altered anatomy, which can be helpful in preventing pICA injury during extended EEAs.

[Convexity hyperostotic meningioma en plaque: a systematic review]. / Ploskostnye giperostoticheskie meningiomy svoda cherepa. Sistematicheskii obzor literatury.

BACKGROUND: Planar hyperostotic meningiomas account for 2-9% of intracranial meningiomas. They are characterized by planar node following the contours of the inner surface of the skull. Hyperostosis is present in most cases. Timely diagnosis of skull base tumors is usually simple due to early involvement of the cranial nerves. However, convexity meningiomas en plaque usually reach large dimensions that complicates surgery and radiotherapy. OBJECTIVE: To analyze the current state of diagnosis, molecular biology and surgical treatment of hyperostotic meningiomas en plaque. MATERIAL AND METHODS: A systematic review was performed in accordance with the PRISMA guidelines. Searching for literature data included the following keywords: «planar meningioma¼, «hyperostotic meningioma¼, «meningioma en plaque¼, «infiltrative meningioma¼. We reviewed the PubMed and Google Scholar databases until May 2023 and enrolled only full-text Russian-, English- or French-language reports. RESULTS AND DISCUSSION: Among primary 332 reports, 35 references met the inclusion criteria. We found less severity or absence of focal neurological symptoms, comparable incidence of intracranial hypertension and no histological differences between planar and nodular meningiomas. Analysis of molecular biological features of planar meningiomas, including cell cultures, is feasible. There is no consensus regarding surgical treatment and radiotherapy. Most publications are case reports. CONCLUSION: The results of treatment of planar hyperostotic meningiomas, especially large and giant ones, are unsatisfactory. There is no a generally accepted algorithm for treating patients in the literature. This problem requires further research.

Prospective Analysis of Radiation-Induced Contrast Enhancement and Health-Related Quality of Life After Proton Therapy for Central Nervous System and Skull Base Tumors.

PURPOSE: Intracerebral radiation-induced contrast enhancement (RICE) can occur after photon as well as proton beam therapy (PBT). This study evaluated the incidence, characteristics, and risk factors of RICE after PBT delivered to, or in direct proximity to, the brain and its effect on health-related quality of life (HRQoL). METHODS AND MATERIALS: Four hundred twenty-one patients treated with pencil beam scanning PBT between 2017 and 2021 were included. Follow-up included clinical evaluation and contrast-enhanced magnetic resonance imaging at 3, 6, and 12 months after treatment completion and annually thereafter. RICE was graded according to Common Terminology Criteria for Adverse Events version 4, and HRQoL parameters were assessed via European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-C30 questionnaires. RESULTS: The median follow-up was 24 months (range, 6-54), and median dose to 1% relative volume of noninvolved central nervous system (D1%CNS) was 54.3 Gy relative biologic effectiveness (RBE; range, 30-76 Gy RBE). The cumulative RICE incidence was 15% (n = 63), of which 10.5% (n = 44) were grade 1, 3.1% (n = 13) were grade 2, and 1.4% (n = 6) were grade 3. No grade 4 or 5 events were observed. Twenty-six of 63 RICE (41.3%) had resolved at the latest follow-up. The median onset after PBT and duration of RICE in patients in whom the lesions resolved were 11.8 and 9.0 months, respectively. On multivariable analysis, D1%CNS > 57.6 Gy RBE, previous in-field radiation, and diabetes mellitus were identified as significant risk factors for RICE development. Previous radiation was the only factor influencing the risk of symptomatic RICE. After PBT, general HRQoL parameters were not compromised. In a matched cohort analysis of 54/50 patients with and without RICE, no differences in global health score or functional and symptom scales were seen. CONCLUSIONS: The overall incidence of clinically relevant RICE after PBT is very low and has no significant negative effect on long-term patient QoL.

Diagnosis of skull-base invasion by nasopharyngeal tumors on CT with a deep-learning approach.

PURPOSE: To develop a convolutional neural network (CNN) model to diagnose skull-base invasion by nasopharyngeal malignancies in CT images and evaluate the model's diagnostic performance. MATERIALS AND METHODS: We divided 100 malignant nasopharyngeal tumor lesions into a training (n = 70) and a test (n = 30) dataset. Two head/neck radiologists reviewed CT and MRI images and determined the positive/negative skull-base invasion status of each case (training dataset: 29 invasion-positive and 41 invasion-negative; test dataset: 13 invasion-positive and 17 invasion-negative). Preprocessing involved extracting continuous slices of the nasopharynx and clivus. The preprocessed training dataset was used for transfer learning with Residual Neural Networks 50 to create a diagnostic CNN model, which was then tested on the preprocessed test dataset to determine the invasion status and model performance. Original CT images from the test dataset were reviewed by a radiologist with extensive head/neck imaging experience (senior reader: SR) and another less-experienced radiologist (junior reader: JR). Gradient-weighted class activation maps (Grad-CAMs) were created to visualize the explainability of the invasion status classification. RESULTS: The CNN model's diagnostic accuracy was 0.973, significantly higher than those of the two radiologists (SR: 0.838; JR: 0.595). Receiver operating characteristic curve analysis gave an area under the curve of 0.953 for the CNN model (versus 0.832 and 0.617 for SR and JR; both p < 0.05). The Grad-CAMs suggested that the invasion-negative cases were present predominantly in bone marrow, while the invasion-positive cases exhibited osteosclerosis and nasopharyngeal masses. CONCLUSIONS: This CNN technique would be useful for CT-based diagnosis of skull-base invasion by nasopharyngeal malignancies.

Tumor Embolization via the Meningohypophyseal and Inferolateral Trunk in Patients with Skull Base Tumors Using the Distal Balloon Protection Technique.

BACKGROUND AND PURPOSE: Tumor embolization through the meningohypophyseal trunk and inferolateral trunk is known to be effective in skull base tumors; however, microcatheter cannulation into these arteries is difficult, and the number of cases that can be safely embolized is limited. In this study, we present a novel embolization procedure for the meningohypophyseal trunk and inferolateral trunk using the distal balloon protection technique and detail its clinical efficacy and complication risks. We developed this procedure to allow safe embolization in patients who cannot be adequately cannulated with microcatheters into these arteries. MATERIALS AND METHODS: Patients who underwent meningohypophyseal trunk or inferolateral trunk embolization using the distal balloon protection technique for skull base tumors at our institution between 2010 and 2023 were included. In this procedure, the ICA was temporarily occluded with a balloon at the ophthalmic artery bifurcation, the microcatheter was guided to the meningohypophyseal trunk or inferolateral trunk vicinity, and embolic particles were injected into the arteries. The balloon was deflated after the embolic particles that had refluxed into the ICA were aspirated. RESULTS: A total of 25 meningohypophyseal trunks and inferolateral trunks were embolized during 21 operations. Of these 25 arteries, only 9 (36.0%) were successfully cannulated with microcatheters. Nevertheless, effective embolization was achieved in all cases. Permanent complications occurred in only 1 case (4.8%) in which the central retinal artery was occluded during inferolateral trunk embolization, resulting in a visual field defect. No permanent complications resulting from the embolic cerebral infarction were observed. Of 16 cases that underwent MR imaging within a week after embolization, however, 11 (68.8%) demonstrated embolic cerebral infarctions. CONCLUSIONS: In patients with skull base tumors with meningohypophyseal trunk or inferolateral trunk feeders that cannot be catheterized directly, embolization using the distal balloon protection technique for tumor supply can be considered as a salvage technique.

Effect of Optic Canal Opening on Postoperative Visual Acuity in Patients with Tuberculum Sellae Meningiomas.

BACKGROUND: Tuberculum sellae meningiomas (TSMs) account for 5 to 10% of all intracranial meningiomas. They typically invade the optic canal and displace the optic nerve upward and laterally. The transcranial approach has been the standard surgical approach, while the transsphenoidal approach has been proposed for its minimally invasive nature; however, some reservations concerning this approach remain. METHODS: From January 2000 to December 2018, a total of 97 patients who were diagnosed with TSM with invasion of the optic canal were enrolled and underwent microsurgery for tumor removal with optic canal opening. A retrospective analysis was performed on the effect of optic canal opening on postoperative visual acuity improvement. The median follow-up was 17.4 months (range: 3-86 months). RESULTS: Among the 97 patients with TSM involving the optic canal, optic canal invasion was seen on preoperative imaging in 73 patients and during intraoperative exploration in all patients. In total, 87/97 patients (89.7%) underwent optic canal opening to remove tumors involving the optic canal, and the rate of total macroscopic resection of tumors invading the optic canal was 100%. Among the 10 patients who did not undergo optic canal opening, the rate of total resection of tumors involving the optic canal was 80% (8/10, p < 0.001). There were no deaths or serious complications. The postoperative visual acuity improvement rate was 64.4%, 23.7% maintained the preoperative level, and the visual acuity deteriorated 11.9%. CONCLUSION: Intraoperative optic canal opening is the key to total resection of TSMs involving the optic canal and improving postoperative visual acuity.

Endonasal, supraorbital, and transorbital approaches: minimal access endoscope-assisted surgical approaches for meningiomas in the anterior and middle cranial fossae.

OBJECTIVE: Minimally invasive endoscope-assisted approaches to the anterior skull base offer an alternative to traditional open craniotomies. Given the restrictive operative corridor, appropriate case selection is critical for success. In this paper, the authors present the results of three different minimal access approaches to meningiomas of the anterior and middle fossae and examine the differences in the target areas considered appropriate for each approach, as well as the outcomes, to determine whether the surgical goals were achieved. METHODS: A consecutive series of the endoscopic endonasal approach (EEA), supraorbital approach (SOA), or transorbital approach (TOA) for newly diagnosed meningiomas of the anterior and middle fossa skull base between 2007 and 2022 were examined. Probabilistic heat maps were created to display the distribution of tumor volumes for each approach. Gross-total resection (GTR), extent of resection, visual and olfactory outcomes, and postoperative complications were assessed. RESULTS: Of 525 patients who had meningioma resection, 88 (16.7%) were included in this study. EEA was performed for planum sphenoidale and tuberculum sellae meningiomas (n = 44), SOA for olfactory groove and anterior clinoid meningiomas (n = 36), and TOA for spheno-orbital and middle fossa meningiomas (n = 8). The largest tumors were treated using SOA (mean volume 28 ± 29 cm3), followed by TOA (mean volume 10 ± 10 cm3) and EEA (mean volume 9 ± 8 cm3) (p = 0.024). Most cases (91%) were WHO grade I. GTR was achieved in 84% of patients (n = 74), which was similar to the rates for EEA (84%) and SOA (92%), but lower than that for TOA (50%) (p = 0.002), the latter attributable to spheno-orbital (GTR: 33%) not middle fossa (GTR: 100%) tumors. There were 7 (8%) CSF leaks: 5 (11%) from EEA, 1 (3%) from SOA, and 1 (13%) from TOA (p = 0.326). All resolved with lumbar drainage except for 1 EEA leak that required a reoperation. CONCLUSIONS: Minimally invasive approaches for anterior and middle fossa skull base meningiomas require careful case selection. GTR rates are equally high for all approaches except for spheno-orbital meningiomas, where alleviation of proptosis and not GTR is the primary goal of surgery. New anosmia was most common after EEA.

The Evolution of Anterior Transpetrosal Approach for the Treatment of Petroclival Meningiomas: A Single-Center 128-Case Experience.

BACKGROUND: The profound understanding of anterior transpetrosal approach (ATPA) is increasingly used to treat petroclival meningiomas (PCMs). We introduce the evolution of ATPA and the outcomes of PCMs treatment. METHODS: Between January 2013 and December 2019, 128 patients with PCMs underwent surgery. According to tumor extension, we classified the 128 patients into 5 types (I-V), introduced key technologies of ATPA into different types for the first time, and achieved a supreme surgical technology. Clinical data, radiological findings, surgical treatments, complications, and patient outcomes were retrospectively analyzed. RESULTS: A total of 22 (17.2%), 44 (34.4%), 25 (19.5%), 29 (22.7%), and 8 (6.3%) patients had type I, II, III, IV, and V disease, respectively. Tumors were gross totally removed (Simpson I and II) in 100 patients (78.1%), subtotally removed (Simpson III) in 20 patients (15.6%), and partially removed (Simpson IV) in 8 patients (6.3%). The progression or recurrence rates were 5% (5/100) for gross totally removed, 22.3% (6/20) for subtotally removed, and 62.5% (5/8; 1 died) for partially removed. According to the Karnofsky Performance Scale and Glasgow Outcome Scale, 108 patients had good recovery (84.4%, 108/128) and 115 were independent (89.8%, 115/128) at the end of follow-up. CONCLUSIONS: Because some key technologies were used in ATPA, the application of ATPA was extended, and greater tumor resection and nerve function protection could be achieved in the treatment of PCMs.