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.

[Transoral approach in surgery for chordomas extending into craniovertebral junction: a systematic review of the literature]. / Transoral'nyi dostup v khirurgii khordom, rasprostranyayushchikhsya v oblast' kraniovertebral'nogo perekhoda: sistematicheskii obzor literatury.

To date, treatment of chordomas involves maximal tumor resection followed by proton therapy. Various approaches are used depending on location of tumor (transcranial and through natural anatomical openings (nose, mouth), as well as their combinations). Although transoral approach has been introduced into neurosurgical practice for a long time, it is routinely used in patients with chordoma only in certain hospitals in the world. OBJECTIVE: To analyze postoperative outcomes in patients with chordomas of skull base and craniovertebral joint after transoral surgery. MATERIAL AND METHODS: We analyzed literature data devoted to patients with chordomas of skull base and craniovertebral joint after transoral surgery or another approach combined with transoral access. Among 111 primary articles, we selected 38 manuscripts including description of 109 patients with skull base chordoma who underwent transoral surgery or combination of approaches including transoral one. RESULTS: Gross total resection was achieved in 45.9% (n=50) of cases including 1 patient after en bloc resection. Subtotal resection was carried out in 28.4% of cases, partial - in 24.8%, biopsy - in 0.9% of cases. The complication rate in this group was 30%. The most common events were swelling of the tongue (10%) and diastasis of posterior pharyngeal wall sutures (8.2%) that required redo surgery. CSF leakage and meningitis were rare (1.8% and 3.6%, respectively). CONCLUSION: Transoral access allows for gross total resection of midline tumors with low incidence of severe complications. Combination of transoral and transcranial approaches is advisable to increase extent of resection.

[Bone defect closure after resection of sphenoorbital meningioma]. / Rekonstruktsiya kostnykh defektov posle udaleniya kranioorbital'nykh meningiom.

Sphenoorbital meningiomas (SOM) are a subgroup of skull base tumors with soft tissue component in the orbit and anterior and/or middle cranial fossa. According to different authors, SOMs account for 2-12% of all intracranial meningiomas. Reconstruction of bone defects after resection of SOM has own nuances. Along with cranial vault repair, patients encounter with cosmetic defects following facial skull lesion, ophthalmic symptoms due to orbital defects, dental and functional problems associated with opening of the mouth in case of damage to maxilla and mandible. Predominant infiltrative growth of tumor and common large bone defects involving various anatomical regions require multiple implants or implants with complex shape. Moreover, contact of implantation area with nasal cavity and paranasal sinuses requires additional impermeability of soft tissue reconstruction and inertness of materials. OBJECTIVE: To summarize available modern data on bone defect closure after resection of SOM. MATERIAL AND METHODS: The authors reviewed available data on bone defect closure after resection of SOM. Effectiveness of modern methods of reconstruction and safety of materials were assessed. RESULTS: We analyzed 96 available references. Technical features of tumor resection, materials used for bone defect closure and modern possibilities of 3D technologies in reconstructive surgery were described. The authors proposed the algorithms for selecting the materials for bone defect closure after resection of SOM. CONCLUSION: Improvement of surgical technique and development of new materials and technologies significantly improve cosmetic and functional results. A large percentage of negative ophthalmologic outcomes and high risk of complications in SOM surgery require further studies and elaboration of modern techniques.

Benign bony tumors of the paranasal sinuses, orbit, and skull base.

Benign bony tumors of the skull base and paranasal sinuses are uncommon entities, with an overall higher incidence in males. Benign bony tumors may lead to local expansion with resultant mass effect of potentially critical structures. Some benign bony tumors may undergo malignant transformation. This article reviews the presentation and management of benign bone tumors of the skull base and paranasal sinuses with special consideration to involvement of the adjacent orbit, intracranial and critical neurovascular structures. This review covers tumor incidence, location, gross and histologic appearance as well as radiographic findings, treatment, and recurrence rates. Tumors discussed in this article include osteochondromas, osteomas, osteoid osteomas, aneurysmal bone cysts, fibrous dysplasia, giant cell tumors, cemento-ossifying fibroma, ameloblastic fibro-odontoma, ecchordosis physaliphora, chondromyxoid fibroma, primary chronic osteomyelitis, primary chronic osteomyelitis, osteochondromyxoma, and dense bone islands.

Synchronized "One-Step" Resection and Cranio-Orbital Reconstruction for Spheno-Orbital Lesions With Custom Made Implant.

BACKGROUND: In the last few years, skull base tumors involving the fronto-orbital region have been approached with complex, invasive, and time-consuming cranial reconstruction techniques. On the other hand, recent custom-made implants allow easier and faster procedures, with excellent aesthetic results. The authors propose an easy surgical-planned protocol with a synchronized "one-step" resection and reconstruction of these complex lesions, with a preformed poly-methyilmethacrylate (PMMA) cranioplasty. METHODS: Our technique consists of a 2-phases procedure. In the first one, the so-called "virtual" phase, the authors get a tailored 3D-PMMA model based on high-resolution (HR) CT-scans of the patient's skull. Afterward, the authors perform the planned craniotomy on the 3D-PMMA model with the assistance of intraoperative navigation system. Therefore, a further CT-scan of the resected model is performed to develop the final implant. In the second phase, the "surgical phase," a single procedure consisting in a cranial resection and custom reconstruction is performed with the assistance of stealth-navigation. The authors describe 6 cases of complex fronto-orbital-sphenoidal benign tumors that required skull reconstruction. All patients were examined 3 months after surgery through cosmetic (facial and eyes symmetry and globe position) and ophthalmology tests (visual field, visual impairment, and diplopia). Postsurgical HR CT-scans of the head and MRI-scans of the brain documented a total resection of the tumor and an optimal accuracy of skull reconstruction. RESULTS: In all cases, the authors obtained a highly accurate skull reconstruction following cranio-orbital tumor resection, with a less aggressive and faster procedure compared to autologous bone graft. Final cosmetic and functional results were excellent, with good results in cases of presurgical exophthalmos and orbital asymmetry. None of the patients developed implant-related complications. CONCLUSIONS: The "one-step" resection and reconstruction of benign tumors involving the spheno-orbital region with neuronavigation assistance is a technique that allows an accurate tumor removal and a cranial-bone reconstruction within a single surgical procedure, with fewer complications and excellent cosmetic and functional results.

Management of Parapharyngeal Space Tumor Using Transoral Robotic Surgery: The Tonsillar Fossa Battlefield.

INTRODUCTION: The management of parapharyngeal space (PPS) tumors is surgical, but the approach remains a challenge. Attention should be paid to avoid intra-operative bleeding, cranial nerves damage, and external scars. PRESENTATION OF CASE: The authors report a case of a 23-year-old female, with complaint of progressive, painless swelling just below the right angle of the mandible of 6-month's duration. Magnetic resonance imaging images reported the presence of an oval-shaped expansive lesion (maximum diameter 3 cm), from the lower polar region of the parotid gland while fine needle aspiration cytology (FNAC) was not diagnostic. We performed a Trans Oral Robotic surgical excision of the tumors with Da Vinci Robot. DISCUSSION: Thanks to a detailed magnification, the authors were able to reach the PPS region through the tonsillar fossa saving the palatine tonsil without any significant bleeding or nerve lesions. The histological examination confirmed the diagnosis of pleomorphic adenoma of parotid gland. The decision on which surgical approach to be used is determined by site, size vascularity, histology of the tumor, and knowledge of radiological images. CONCLUSION: There is not only 1 surgical approach for PPS tumors but the surgeon must know all the different options and possible outcomes. Transoral Robotic Surgery approach with Da Vinci could represent a valid option with a good knowledge of Robot surgical instruments and a detailed preoperative plan.

Endoscopic anatomical study of the trans-lateral molar approach to the infratemporal fossa.

BACKGROUND: The infratemporal fossa (ITF) is located deep in the skull base. Recently, the endoscopic transoral approach has enabled maxillofacial surgeons to access the ITF using a less invasive approach compared to the traditional transfacial and endonasal endoscopic approaches. OBJECTIVE: The present study aims to provide maxillofacial surgeons with new data concerning direct endoscopic measurement and precise anatomical topography features of the endoscopic trans-lateral molar approach to ITF by comparing the endoscopic and regional anatomy of ITF. A clinical case receiving the proposed surgical approach is used to determine the feasibility of this technique. METHOD: The anatomical data were obtained by measuring the bone anatomical landmarks and analyzing the CT imaging data using GE's Advance Windows 4.1 software on 25 subjects (50 sides). Morphological pictures of the regional anatomy and endoscopic anatomy were obtained from 6 (12 sides) adult cadaver heads, and the anatomical features were described. The present study reports the management of one case using the proposed surgical approach. RESULTS: The proposed surgical approach clearly revealed neurovascular, muscular, and surgical landmarks in the ITF. The surgical case supports the minimally invasive treatment approach, which could rapidly access the ITF and completely excise benign tumors. CONCLUSION: The anatomical studies and surgical case presentation helps us understand the spatial relationship of surgical landmarks of the surgical approach to the ITF for the treatment of benign lesions in the deep cranial base area.

Atypical Intracranial Compound Simil Odontoma.

Odontoma is the most common mixed epithelial and mesenchymal tumour-like malformation which affects maxillary bones. Clinically, Odontomas present as lesions of benign behavior, causing little or no deformity, are asymptomatic, with self-limited growth and usually detected on routine radiographs. Radiographically, they are radiopaque lesions, well-demarcated surrounded by a thin soft tissue capsule. Compound odontomas consist of numerous tooth-like structures, whereas in complex odontomas it consists of a disorganized mass of calcified tissue. The aim of this article was to report an atypical case of intracranial compound odontoma, in the middle cranial fossa, reaching the sphenoidal sinus, which has been followed for 10 years.

Recurrent mandibular ameloblastoma with anterior skull base invasion: Case report.

Recurrent ameloblastoma with skull base invasion is a rare clinical entity with poor prognosis. We report a case of a mandibular ameloblastoma recurrence involving the anterior skull base. The diagnostic and therapeutic processes are presented with emphasis on the radiologic features of ameloblastoma. Another aim of this case report is to underline the importance of close and long-term follow-up after resection. Ameloblastoma recurrences are frequent and mainly occur after incomplete surgical resection. These recurrences may be diagnosed late because of lack of symptoms in the mandibular area.

Craniofacial approaches and reconstruction in skull base surgery: techniques for the oral and maxillofacial surgeon.

Skull base surgery (SBS) is considered the standard of care in treating benign and malignant lesions of the cranial base. SBS is a multidisciplinary team approach used to treat these complex lesions that may have intracranial extension. SBS can be broken down into 3 steps. Transfacial access is performed, followed by resection with sound oncologic principles, and then reconstruction of the cranial base and facial structures. Functional and esthetic concerns must be addressed by the surgeons. Oral and maxillofacial surgeons frequently perform elective facial osteotomies and treat victims of cranial base trauma. These same principles can be applied to SBS as a part of the skull base team.

Endoscopic multiport resection of a transspatial, retromaxillary tumor.

Tumors of the retromaxillary tissues can grow to involve multiple deep, skull base spaces, including the pterygopalatine fossa, infratemporal fossa, and the parapharyngeal space. Management of these tumors must account for heterogeneous pathology as well as the critical neurovasculature in and surrounding these spaces. Traditionally, these tumors have been approached the open skull base or anterior craniofacial approaches. Modern endoscopic endonasal and multiport approaches have increasingly become favored for certain tumors in the retromaxillary skull base region. In this report, we present the case of a 42-year-old male presented with refractory headache and was found to have a left-sided 5.0 cm tumor of the retromaxillary spaces with widening of foramen ovale. Differential diagnosis included schwannoma of the mandibular nerve, paraganglioma, salivary gland tumor, or soft tissue tumor. The tumor was approached via an expanded endoscopic approach to the pterygopalatine fossa and augmented with a Caldwell-Luc maxillotomy, to access the posterolateral extent of the tumor. A 2-surgeon team utilized visualization and instrumentation through both the transnasal and transmaxillotomy corridors to completely mobilize and remove the tumor. Post-resection imaging demonstrated complete removal of the tumor and pathology confirmed the diagnosis of schwannoma. Custom, multiport surgery can be a safe, less invasive approach for successful management of well selected retromaxillary skull base tumors.

Embolization of Skull Base Meningiomas with Embosphere Microspheres: Factors Predicting Treatment Response and Evaluation of Complications.

OBJECTIVE: Preoperative embolization for intracranial meningiomas can cause tumor necrosis, reduce intraoperative blood loss, and facilitate surgery. This study aimed to evaluate the efficacy of tumor embolization using Embosphere microspheres for skull base meningiomas and analyze postembolization plain computed tomography (CT) and magnetic resonance imaging (MRI) scans to identify findings that could potentially predict treatment response. METHODS: Between April 2014 and April 2020, 80 patients with skull base meningiomas presenting at our medical center underwent embolization with Embosphere microspheres. The effects of tumor embolization were evaluated through a comparison of postembolization plain CT and contrast-enhanced MRI. RESULTS: A total of 143 vessels (102 of 108 external carotid artery branches and 41 of 65 internal carotid artery branches) from 80 skull base meningiomas were embolized with Embosphere microspheres. Microspheres 100-300 µm in size were used in 2 cases, microspheres 300-500 µm in size were used in 12 cases, and microspheres 500-700 µm in size were used in 66 cases. Postembolization contrast-enhanced MRI showed reductions in enhancing lesions within the tumor in 55 of 80 cases. Postembolization plain CT scans showed high-density lesions within the tumor in 41 of 55 cases. Thus, reductions in enhancing lesions on postembolization contrast-enhanced MRI were statistically significantly associated with the presence of high-density lesions on postembolization plain CT (P < 0.001). Embolization-related neurological complications occurred in 3 cases. CONCLUSIONS: Embosphere microspheres are user friendly and effective embolic materials for the embolization of skull base meningiomas. Postembolization contrast-enhanced MRI and plain CT findings may be useful for evaluating the effects of tumor embolization.

Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach.

Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

Diffuse large B cell lymphoma involving Meckel's cave masquerading as biopsy-negative giant cell arteritis: a case report.

BACKGROUND: Given the absence of consensus diagnostic criteria for giant cell arteritis, clinicians may encounter difficulty with identification of new-onset headache in patients older than age 50 years presenting with visual changes and elevated inflammatory markers, particularly if temporal artery biopsies are performed and negative. CASE PRESENTATION: We present a case of a 57-year-old white man with headache, diplopia, and jaw paresthesia initially diagnosed and managed as steroid-refractory biopsy-negative giant cell arteritis. Further investigation disclosed evidence of soft tissue infiltration into Meckel's (trigeminal) cave bilaterally. Positron emission tomography suggested the presence of a lymphoproliferative disorder. Histology confirmed the diagnosis of diffuse large B cell lymphoma. CONCLUSIONS: Metastatic involvement in Meckel's cave in diffuse large B cell lymphoma is extremely rare and presents a diagnostic challenge. Patients with suspicion of giant cell arteritis should undergo advanced imaging, particularly those with negative biopsy, atypical features, or lack of response to standard therapy, in order to assess for the presence of large-vessel vasculitis or other mimicking pathologies.

Extreme Lateral Transodontoid Approach for Resection of Clival Chordoma: 2-Dimensional Operative Video.

This 15-yr-old girl presented with nasal obstruction and dysphagia of duration 3 mo and 8 to 10 pounds of weight loss. On examination, she had a hoarse voice and left tongue deviation without weakness or myelopathy. Computed tomography (CT) demonstrated an erosive lesion arising from the clivus and left occipital condyle. Magnetic resonance imaging (MRI) demonstrated a T1-isointense, T2-hyperintense, enhancing mass centered at the occipital condyle and extending into the craniovertebral junction (CVJ), causing severe brainstem compression and extending inferiorly to C2 and anteriorly into the retropharyngeal space. The patient underwent transoral biopsy to confirm the diagnosis of chordoma and complete tumor resection via a left extreme lateral transodontoid (ELTO) approach. This approach was chosen because it provides bilateral exposure to the ventral CVJ and retropharyngeal space and allows for complete tumor removal using a single approach, although it requires an experienced surgeon. The ELTO incision should provide adequate exposure for occipitocervical fusion (OCF) after the destabilization of the CVJ. Transposition of the vertebral artery and odontoidectomy are key maneuvers that provide exposure to the ventral CVJ bilaterally. Dural closure is performed primarily and augmented with fat, fibrin glue, and temporary cerebrospinal fluid diversion. Postoperative MRI showed a gross-total resection and decompression of the brainstem at the CVJ. The patient remained in a cervical collar until OCF. Postoperatively, she had left vocal cord paralysis and moderate weakness with left arm abduction at the deltoid. At 2-mo follow-up, she had improved lower cranial neuropathies, tolerated oral intake, and was scheduled to begin proton beam therapy. The patient provided consent for publication.

Functional Outcomes Following Temporomandibular Joint Dissection Performed During Surgery for Skull Base Tumors.

BACKGROUND: During skull base tumor surgery, temporomandibular joint (TMJ) dissection is commonly performed. The impact of this procedure on patients' postoperative diet and TMJ function is a matter of concern to surgeons. METHODS: We reviewed the Craniomandibular Index (CMI) for 32 patients (15 men and 17 women) who underwent TMJ dissection during surgery for skull base tumors between August 2015 and May 2018. RESULTS: Fifteen patients underwent removal of the mandibular condyle, and 17 had the condyle preserved. Twenty-one patients mainly underwent infratemporal fossa approach, and 11 underwent extended temporal bone resection. No significant difference between pre- and postoperative diet was observed in any group. Significant differences in CMI index were seen in all groups. The highest score was 0.115 of Dysfunction Index, observed postoperatively in the group that underwent condyle removal. CONCLUSIONS: For skull base tumor surgery, TMJ dissection has no significant impact on postoperative diet. Patients who underwent removal of the mandibular condyle have significantly worse postoperative TMJ function.

Oral and maxillofacial manifestations of familial adenomatous polyposis (Gardner's syndrome): a report of two cases.

AIM: The aim of this case report is to emphasize the importance of an early diagnosis of Gardner's syndrome through the detection of lesions appearing in the oral and maxillofacial area as well as to present two cases of the disease. BACKGROUND: Gardner's syndrome is an autosomal dominant disease characterized by gastrointestinal polyps that develop in the colon as well as in the stomach and upper intestine, along with multiple osteomas, skin, and soft tissue tumors. Cutaneous findings may include desmoid tumors, epidermoid cysts, and other benign tumors. Early diagnosis and therapy of the disease are critical because polyps have a 100% risk of undergoing malignant transformation. Craniomaxillofacial manifestations (osteoma formation, tooth impaction, diffuse opacities in the skull, mandible and maxilla, scalp tumors) usually precede polyposis. REPORT: Case 1: Gardner's syndrome was diagnosed in a 25-year-old Caucasian man who was referred by his endodontist for evaluation of an uncommon radiographic image in the mandibular molar area. Further investigation revealed a familial adenomatous polyposis (FAP) complicated by adenocarcinoma of the colon. A colectomy and an ileorectal anastomosis were performed. Case 2: A 12-year-old Caucasian girl, who is a niece of the patient described in Case 1, presented with progressive difficulty with mouth opening but no complaints of digestive problems. Radiographic examination revealed multiple radiopacities in the maxilla, mandible left temporomandibular joint, and in the left mandibular angle. Multiple impacted teeth were present. A colonoscopy was suggested, but the patient's parents decided to continue the investigation and treatment with their own physician in their home town. SUMMARY: Since an early diagnosis is essential and general dental practitioners may be the first healthcare professionals to suspect the diagnosis, it is important for them to be familiar with the features of Gardner's syndrome.

Determination of Normal Values of the Basal Angle in the Era of Magnetic Resonance Imaging.

BACKGROUND: The flexion of the skull base (basal angle [BA]) is the inclination between the anterior fossae and the basilar ramp of the occipital and sphenoid bones. An increased BA, termed platybasia, is usually associated with basilar invagination. BA reference values in the magnetic resonance imaging (MRI) era and the diagnosis of platybasia are of clinical importance. The transnasal approach has been the surgical technique of choice to remove the odontoid process in cases of ventral brainstem compression in patients with platybasia. The knowledge of normal BA values has been influenced by technological image acquisitions. The aim of this study was to determine the normal BA values in normal subjects in the MRI era. METHODS: For the determination of normal BA values, the literature reporting these values in normal individuals was reviewed and a meta-analysis of pertinent studies was performed. RESULTS: A total of 8 articles were included in this study, evaluating a total of 667 individuals. A summary measure of the results was obtained. The data obtained in this analysis provided a final basal angle value of 116.5 degrees (95% confidence interval, 104.39-128.7). The normal basal angle ranges between 104 and 129 degrees. CONCLUSION: Platybasia can be defined as a value >129 from the basal angle.

[Surgical treatment of invasive tumors of the nasal cavity and paranasal sinuses involving the inferior and middle cranial fossae].

An analysis of combined treatment of 11 patients with tumors of the paranasal sinuses involving the skull base was made. Radical surgical interventions were performed in the volume of nasal exenteration, maxillectomy and orbital exenteration, nasal exenteration, and total maxillectomy. The technique of surgical interventions and results of treatment are described.

Preoperative Embolization of Skull Base Meningiomas: Outcomes in the Onyx Era.

OBJECTIVE: Preoperative embolization may facilitate skull base meningioma resection, but its safety and efficacy in the Onyx era have not been investigated. In this retrospective cohort study, we evaluated the outcomes of preoperative embolization of skull base meningiomas using Onyx as the primary embolysate. METHODS: We queried an endovascular database for patients with skull base meningiomas who underwent preoperative embolization at our institution in 2007-2017. Patient, tumor, procedure, and outcome data were analyzed. RESULTS: Twenty-eight patients (28 meningiomas) underwent successful preoperative meningioma embolization. The mean patient age ± SD was 56 ± 13 years, and 18 patients (64%) were women. The mean tumor size was 49 cm3. There were 1, 2, or 3 arterial pedicles embolized in 21 cases (75%), 6 cases (21%), and 1 case (4%), respectively. The embolized pedicles included branches of the middle meningeal artery in 19 cases (68%), the internal maxillary artery in 8 cases (29%), the ascending pharyngeal artery in 2 cases (7%), and the posterior auricular, ophthalmic, occipital, and anterior cerebral arteries in 1 case each (4%). The embolysates used were Onyx alone in 20 cases (71%), n-butyl cyanoacrylate alone in 3 cases (11%), coils/particles and Onyx/n-butyl cyanoacrylate in 2 cases each (7%), and Onyx and coils in 1 case (4%). The median degree of tumor devascularization was 60%. Significant neurologic morbidity occurred in 1 patient (4%) who developed symptomatic peritumoral edema after Onyx embolization. CONCLUSIONS: For appropriately selected skull base meningiomas supplied by dura mater-based arterial pedicles without distal cranial nerve supply, preoperative embolization with current embolysate technology affords substantial tumor devascularization with a low complication rate.