Endovascular treatment of anterior cranial base dural arteriovenous fistulas as a first-line approach: a multicenter study.

OBJECTIVE: Anterior cranial fossa dural arteriovenous fistulas (DAVFs) have been almost exclusively considered as surgical lesions. However, new advances in endovascular technology have made the endovascular treatment (EVT) of ethmoidal DAVFs feasible. The aim of this study was to report the clinical and angiographic outcomes of patients harboring DAVFs of the anterior cranial fossa who had undergone EVT as a first-line approach. METHODS: This was a retrospective study of a consecutive series of patients harboring anterior cranial base DAVFs who had undergone EVT as a first-line approach at four institutions. Angiographic follow-up was performed at 6 months. Immediate and late serious clinical events were assessed during follow-up, including death and stroke. Special emphasis was given to visual status before and after the treatment. RESULTS: Between 2008 and 2020, 37 patients with ethmoidal DAVFs were admitted to the participating centers. In 2 patients, EVT was not attempted; therefore, 35 patients underwent EVT as a first-line procedure. An isolated transarterial approach was performed in 19 (54.3%) patients. The transvenous approach was performed exclusively in 12 (34.3%) patients, and combined access was used in 4 (11.4%) patients. The most frequently used arterial access route was the ophthalmic artery in 82.6% of the patients. Immediately, complete angiographic occlusion was achieved in 31 (91.2%) of 34 patients whose treatment was accomplished. Six-month control angiography revealed that 30 (88.2%) DAVFs were totally occluded. Complications occurred in 3 (8.8%) patients, including 1 (2.9%) patient who had central retinal artery occlusion. No significant difference in complications or occlusion rates was noted between the transarterial and transvenous approaches. CONCLUSIONS: Most anterior cranial base DAVFs can be successfully treated via an endovascular approach. Neurological and visual complications are rare, even if the ophthalmic artery is used as the primary access route. Efforts should be focused on prospectively comparing the results of EVT and surgical management.

Same viewing angle, minimal craniotomy enlargement, extreme exposure increase: the extended supraorbital eyebrow approach.

The supraorbital eyebrow approach (SEa) has been commonly used as a straightforward route to reach lesions located in the anterior cranial fossa. The reduced surgical exposure provided by this approach limits its applicability. A modification of the SEa, the extended supraorbital eyebrow approach (X-SEa), allows use of the transylvian corridor to approach parasellar lesions, while maintaining most of the aesthetic advantages of the SEa. To quantify the surgical exposure and maneuverability provided by the X-SEa using a cadaveric study. Eleven heads were used to obtain all stereotactic measurements. Surgical exposure and maneuverability were measured by means of the area of exposure and the angles of attack along key representative points in the anterior circulation. The horizontal angle of attack at the middle cerebral artery provided by the X-SEa was larger than that provided by the SEa (32.6 vs 18.4°, p = 0.009). The X-SEa afforded broader vertical angles of attack at all targets in the anterior circulation (p < 0.05). The total area of exposure provided by the X-SEa was significantly larger than that provided by the SEa (1272 vs 978 ± 156 mm2, p = 0.003). The area of exposure in the ipsilateral trigon and in the midline quadrangle was also significantly larger for the X-SEa (paramedian 195 vs 121 mm2, p = 0.01; midline 1310 vs 778 mm2, p = 0.002). The X-SEa increases the exposure and surgical maneuverability along the anterior and middle cranial fossa when compared to the standard SEa.

Anterior skull base olfactory tumours, which is what? A case report and review.

Intracranial schwannomas not originating from cranial nerves are rare. In this paper, we report a case of a 50-year-old male who presented with worsening headaches, diplopia and nausea over two years. Radiological imaging revealed a large tumour arising from the olfactory groove region with a preoperative diagnosis of olfactory groove meningioma (OGM). Intraoperatively, the tumour originated from the region of the attachment of the falx to the crista galli. The patient recovered without complication and histopathology reported an unexpected diagnosis of WHO Grade 1 schwannoma. However, as olfactory groove schwannomas (OGSs) cannot be distinguished from olfactory ensheathing cell tumours (OECTs), it is possible that the tumour could have been either an OGS or an OECT. Distinguishing between OGSs, OECTs and OGMs preoperatively is difficult. OGMs exhibit distinct histopathological features from OGSs/OECTs, however, OGSs and OECTs currently cannot be distinguished from each other. Here, we review the literature to discuss the differentiating features and cellular origins of these three tumours.

TRANS-FRONTAL SINUS APPROACH FOR OLFACTORY GROOVE MENINGIOMAS: A 19 YEAR EXPERIENCE.

INTRODUCTION: Olfactory groove meningiomas (OGMs) account for 8-13 % of all intracranial meningiomas. The gold standard of treatment is generally surgery, however various approaches have been used and the literature is still uncertain about the superiority of one treatment over the others. The most debated techniques are traditional microscopic open approaches versus the endoscopic endonasal ones. The aim of this paper is to prove a valid surgical route that gathers the benefits of both endoscopic and transcranial routes. METHODS: Fifty consecutive patients underwent trans-frontal sinus surgical removal of an OGM between January 2000 and January 2019 at the Neurosurgical Departments in Torino, Brescia and Legnano (Italy). The clinical features were collected in a database and compared with neuroimaging and outcomes. All patients were investigated with neuroimaging techniques. Clinical evaluations were performed 3-4 months and 1 year after surgery, together with neuroradiological follow-up. RESULTS: All patients with OGM underwent Simpson grade I resection. The most common neurological symptom leading to neuroradiological evaluations were headaches (36 %), followed by behavioural changes (30 %), hyposmia/anosmia (12 %), visual impairments (6%) and focal deficits (6%). At 3-4 months follow-up 48 patients underwent a brain MRI (2 patients underwent a brain CT), and a complete resection was confirmed in 45 patients (94 %). CONCLUSIONS: Despite different techniques and studies supported by good evidence, there is no consensus on the best surgical approach for OGMs. The data shown in this article suggests that the trans-frontal sinus approach is a valid alternative to an endoscopic approach and the classical transcranial routes, collecting benefits from both approaches.

A Systematic Review on Outcomes of Anterior Skull Base Reconstruction.

INTRODUCTION: Anterior skull base resection often results in large defects that need to be reconstructed. This can be done using loco-regional, free flaps or both. OBJECTIVE: The aim of this systematic review is to evaluate the surgical outcomes (mortality, complication rates and functional outcomes) for patients undergoing anterior skull base reconstruction. METHODS: Electronic databases (MEDLINE, EMBASE and Scopus) were systematically searched for relevant articles from 1974 to March 2018. A total of 41 studies were included in this systematic review. No randomized controlled trials were identified; therefore, a meta-analysis was not performed. RESULTS: Mortality from anterior skull base reconstruction were about 0-4% for loco-regional flaps while free flaps were around 0-7%. Overall complications ranged from 0% to 43% in loco-regional flaps, while rate of complications for free flaps ranged from 25% to 66.7%. Flap complications ranged from 0% to 14% for free flaps and 0% to 35% for local flaps. Quality-of-life measures did not differ significantly depending on surgical approach but were worse for patients with malignancies. CONCLUSION: Due to varying standards of reporting of outcomes, lack of a standardized classification system for anterior skull base defects and absence of clinical trials, we were unable to perform a meta-analysis in this systematic review. Recommendations to guide future studies are proposed.

Utility of Schwann/2E and Sox10 in distinguishing CD57-negative olfactory groove schwannoma from olfactory ensheathing cell tumor: A case report and review of the literature.

We herein report a patient who was diagnosed as having olfactory groove schwannoma (OGS) which was negative for CD57 (Leu7) but positive for Schwann/2E and Sox10. A 13-year-old female with a chief complaint of headache was referred to our department due to a tumor lesion in the anterior skull base identified by magnetic resonance imaging (MRI). At the first visit, she did not exhibit altered consciousness, motor palsy, anosmia, seizures, or café au lait spots. On contrast-enhanced computed tomography (CT), a heterogeneously enhanced tumor, 50 × 45 × 50 mm in size, was observed at the anterior skull base. The left cribriform plate was thinner on bone window CT. The tumor exhibited strong, heterogeneous gadolinium enhancement on MRI as well. Slight tumor staining was observed by angiography of the left internal carotid artery but not the left external carotid artery. The patient was preoperatively diagnosed as having meningioma and underwent gross tumor resection via the basal interhemispheric approach. The tumor was strongly positive for S-100 protein and negative for epithelial membrane antigen and CD57 by immunostaining. The tumor was positive for both Schwann/2E and Sox10, which aided in the differential diagnosis between OGSs and olfactory ensheathing cell (OEC) tumors, and the definitive diagnosis was OGS. The assessment of immunoreactivities for Schwann/2E and Sox10 might be necessary to differentiate CD57-negative Schwannomas from OEC tumors.

Mixed Olfactory Neuroblastoma and Adenocarcinoma with In Situ Neuroendocrine Hyperplasia.

Olfactory neuroblastoma (ONB) is a rare malignant neoplasm arising from the superior aspect of the nasal vault. Cases are characterised by insidious clinical presentation and high rates of recurrence despite surgical resection and adjuvant radiotherapy. There are a small number of reports showing ONB with divergent epithelial or ganglionic differentiation, and ONB has also been found to coincide with adenocarcinoma. We present a case of mixed ONB with adenocarcinoma. The clinical presentation was unusual, with a tonic-clonic seizure preceded by chronic headache and anosmia. Imaging revealed a mass extending from the olfactory recess of the left nasal cavity through the cribriform plate to the anterior cranial fossa. The pathology demonstrated intraepithelial neuroendocrine cell hyperplasia in the left olfactory groove. This finding provides a unique insight into the cellular origin of this rare tumour, and appears to confirm the theory that ONB arises from neural stem cells in the olfactory neuroepithelium. Despite radical treatment, the patient suffered a distant recurrence within 1 year of treatment, which underlines the aggressive nature of this tumour.

Does paranasal sinus development affect olfactory fossa depth and lateral lamella length?

OBJECTIVES: To investigate the olfactory fossa depths and lateral lamella lengths of patients with different types of developmental disorders of paranasal sinuses in comparison with normal controls. STUDY DESIGN: Retrospective, archival, radio-anatomical study. METHODS: We included 58 patients with maxillary sinus hypoplasia, 50 patients with frontal sinus hypoplasia/aplasia, 50 patients with sphenoid sinus hypoplasia/aplasia, and 40 normal controls. Reviewing paranasal computerized tomography scans, we noted the olfactory fossa depths and lateral lamella lengths of all the groups and compared between the hypoplasia groups and the control group. RESULTS: Compared with the normal controls, the maxillary hypoplasia group (P < 0.001), frontal hypoplasia/aplasia group (P = 0.004), and sphenoid hypoplasia/aplasia group had significantly deeper olfactory fossa (P = 0.003). The mean lateral lamella lengths in the type 1, type 2, and type 3 hypoplastic maxillary sinus groups were significantly greater compared with that in the control group (P < 0.001). Additionally, the mean lateral lamella lengths in the hypoplastic frontal sinus, aplastic frontal sinus, and hypoplastic sphenoid sinus groups were significantly greater compared with that in the control group (P < 0.001). CONCLUSION: The patients with pneumatization defects of the maxillary, frontal, and sphenoid sinuses had deeper olfactory fossa and longer lateral lamella related to increased risk of skull base injury during endoscopic sinus surgery. LEVEL OF EVIDENCE: 3 Laryngoscope, 129:2458-2463, 2019.

Classification and Microvascular Flap Selection for Anterior Cranial Fossa Reconstruction.

BACKGROUND: Microvascular reconstruction of the anterior cranial fossa (ACF) creates difficult challenges. Reconstructive goals and flap selection vary based on the defect location within the ACF. This study evaluates the feasibility and reliability of free tissue transfer for salvage reconstruction of low, middle, and high ACF defects. METHODS: A retrospective review was performed. Reconstructions were anatomically classified as low (anterior skull base), middle (frontal bar/sinus), and high (frontal bone/soft tissue). Subjects were evaluated based on pathologic indication and goal, type of flap used, and complications observed. RESULTS: Eleven flaps in 10 subjects were identified and anatomic sites included: low (n = 5), middle (n = 3), and high (n = 3). Eight of 11 reconstructions utilized osteocutaneous flaps including the osteocutaneous radial forearm free flap (OCRFFF) (n = 7) and fibula (n = 1). Other reconstructions included a split calvarial graft wrapped within a temporoparietal fascia free flap (n = 1), latissimus myocutaneous flap (n = 1), and rectus abdominis myofascial flap (n = 1). All 11 flaps were successful without microvascular compromise. No complications were observed in the high and middle ACF defect groups. Two of five flaps in the low defect group using OCRFFF flaps failed to achieve surgical goals despite demonstrating healthy flaps upon re-exploration. Complications included persistent cerebrospinal fluid leak (n = 1) and pneumocephalus (n = 1), requiring flap repositioning in one subject and a second microvascular flap in the second subject to achieve surgical goals. CONCLUSION: In our experience, osteocutaneous flaps (especially the OCRFFF) are preferred for complete autologous reconstruction of high and middle ACF defects. Low skull base defects are more difficult to reconstruct, and consideration of free muscle flaps (no bone) should be weighed as an option in this anatomic area.

Rostral cranial fossa as a site for cerebrospinal fluid drainage - volumetric studies in dog breeds of different size and morphotype.

BACKGROUND: Hydrocephalus is a multifactorial condition, whose aetiology is not fully understood. Congenital hydrocephalus frequently occurs in small and brachycephalic dog breeds. Although it is widely accepted that the cribriform plate located in the rostral cranial fossa (RCF) is a site of cerebrospinal fluid (CSF) drainage, the RCF has not been studied extensively. Literature reports indicate that a decreased caudal cranial fossa (CCF) volume in the course of the Chiari-like malformation may obstruct CSF circulation. We hypothesised that morphological diversity among different breeds in the volume of the RCF may affect CSF circulation. The aim of the study was to carry out a volumetric analysis of the RCF and the cranial cavity and to determine the ratio between them in dog breeds of different size and morphotype. We performed computed tomography (CT) morphometric analysis of the RCF compartment by obtaining volume measurements from the transverse and reformatted sagittal and dorsal planes. RESULTS: The rostral cranial fossa percentage - volume of the rostral cranial fossa/volume of cranial cavity × 100 (volRCF/volCC × 100) was lower in small and brachycephalic dog breeds than in the other dogs. CONCLUSIONS: A reduced RCF volume was detected in small and brachycephalic dog breeds, some of which are predisposed to congenital hydrocephalus. This may lead to overcrowding of brain parenchyma in the RCF and may impede CSF circulation. Our observations may be useful for future studies focusing on the causes and new therapies to treat conditions such as hydrocephalus and syringomyelia.

Plasma Cell Granuloma of the Jaw and the Infratemporal Fossa: A Clinical Case.

Plasma cell granuloma or inflammatory pseudotumor (IPT) is diagnosed by a process of elimination. The precise etiology is unknown, although it can occur after a bout of periodontal infection. This report describes the various stages of progression for this ailment. A 49-year-old woman with no noteworthy medical history presented with a recurrent periodontal abscess accompanied by progressive and severe destruction of the right maxilla. There was invasion of the infratemporal fossa and very tight trismus. Histologic examination indicated a reactive plasma cell granuloma. IPT is an entity recognized by the World Health Organization. A triggering infectious or inflammatory factor is often present. In the maxilla, progression is very aggressive. Treatment relies on corticotherapy, with or without radiotherapy, and administration of cyclosporine.

Olfactory Groove Schwannoma ­ A Case Report and Literature Review

Olfactory groove schwannomas (OGSs) are rare benign tumors of the anterior skull base region. Considering the lack of Schwann cells in the optic and olfactory nerves, their origin remains enigmatic. Despite the precursor cell, total resection of the lesion is curative, as long as the histopathological features of the tumor are compatible with schwannoma. We report the case of a 32-year-old woman, addicted to crack, who was brought to the hospital presenting with cognitive dysfunction after being physically assaulted, whose neuroimaging revealed a large extra-axial mass in the subfrontal sagittal region. The presentation, immunohistochemical markers and histogenesis are discussed in the present study, along with a literature review.

[A supraorbital trans-eyebrow approach in surgery of chiasmatic-sellar and anterior cranial fossa tumors]. / Supraorbital'nyi transbrovnyi dostup v khirurgii opukholei khiazmal'no-selliarnoi oblasti i perednei cherepnoi iamki.

OBJECTIVE: to analyze 31 resections of chiasmatic-sellar region (CSR) and anterior cranial fossa (ACF) tumors using the supraorbital trans-eyebrow approach (STA). MATERIAL AND METHODS: We analyzed medical histories of 31 patients who underwent tumor resection using STA in the period between October 2013 and April 2017. We analyzed the age and gender of patients, size and location of the tumor, presence of a neurological deficit, vision and olfactory functions before and after surgery, surgery duration, amount of intraoperative blood loss, rate of frontal sinus trephination and nasal liquorrhea, hemorrhagic and ischemic complications after surgery, Simpson grade of tumor resection, patient's condition before and after surgery (Glasgow Outcome Scale and Karnofsky Scale), and degree of patient satisfaction with the cosmetic result of surgery. A total of 26 meningiomas (20 sphenoid plate, tubercle, and diaphragm tumors, 3 lesser sphenoid wing meningiomas, 2 orbital roof tumors, and 1 anterior clinoid process meningioma), 3 frontal lobe gliomas, and 2 pituitary adenomas were resected. RESULTS: In all 31 operations, the approach was adequate and enabled tumor resection without lethal outcomes. The mean surgery duration was 174.6±64.4 min. The mean blood loss was 190±96.6 mL (50-380 mL). After surgery, none of the patients developed motor deficits and new epileptic seizures. Neurological deficit aggravation in the form of impaired vision and mental disorders occurred in 8 (25.8%) patients. Vision impaired in 4 (12.9%) patients, improved in 6 (19.3%) patients, and remained unchanged in 21 (67.7%) patients. An endocrinological deficit in the form of partial hypopituitarism developed in 3 (9.6%) patients; in 4 (12.9%) patients, there were mental disorders that regressed by the end of the first month of therapy. There were no intracerebral and subarachnoid hemorrhages. In 2 (6.4%) patients, small epidural hematomas were diagnosed, which did not require surgical treatment. There were only good outcomes (a GOS score of 4 or 5). After surgery, the median Karnofsky index in the STA group was 90±7. In all 31 (100%) patients, the postoperative wound healed by primary intention, without infectious complications and wound liquorrhea. One (4%) patient developed eyebrow palsy; 3 (12%) patients had hypoesthesia in the supraorbital region. The mean VAS score of patient satisfaction with the cosmetic result was 9.36 (median 10±1). The mean follow-up period was 16.2±13.5 months (2-38 months). CONCLUSION: The STA is adequate for removal of CSR and ACF tumors under proper selection of patients. It provides an adequate view of anatomical structures and enables successful tumor resection through a less traumatic access.

Ophthalmological symptoms in children with intracranial cysts.

The purpose of this study was to perform an ophthalmological assessment in children with intracranial cysts and to assess the correlation between the occurrence of cysts and visual disorders. The documentation of 46 children with intracranial cysts, monitored by the Children's Outpatient Ophthalmology Clinic, Poznan, Poland was analysed. The best corrected visual acuity (BCVA), the alignment of the eyes, visual evoked potentials (VEP), comprehensive eye examination were performed in all patients. Additional ophthalmological tests were conducted to eliminate other causes of decreased visual acuity.Included in the final analysis were 26 children (52 eyes). The average age at the last visit was 10.3 years. Sixteen children (61.5%) had arachnoid cysts located in the posterior cranial fossa, 3 children (11.5%) in the middle cranial fossa, while 7 children (27%) had a pineal cyst. Decreased BCVA was found in 13 children, abnormal VEP in 13, strabismus in 14 patients (53.9%), nystagmus in 5 patients (19.2%), and double vision in 2 patients (7.7%). Numerous visual disorders in children with intracranial cysts suggest the necessity to carry out enhanced ophthalmological diagnostics in these patients. In the examined patient group, visual disorders occurred mostly in the case of arachnoid cysts of the posterior fossa.

Endoscopic Superior Ethmoidal Approach for Anterior Cranial Base Resection: Tailoring the Approach for Maximum Exposure with Preservation of Nasal Structures.

BACKGROUND: Traditional endoscopic anterior cranial base resection involves the total removal of the ethmoidal cells, including the middle and superior turbinates. This is associated with increased volume of the nasal cavity postoperatively, with increased crusting and permanent change of the nasal airflow. Here we provide a step-by-step description of the technique and evaluate the feasibility of the superior ethmoidal approach for anterior cranial base resection with maximum exposure of the anterior cranial base while keeping the middle turbinates, uncinate processes, and ostiomeatal complexes intact. METHODS: Three fresh cadaveric heads were used for dissections. This technique was successfully performed in 2 consecutive cases of large olfactory groove meningiomas. RESULTS: In all anatomic dissections, satisfactory exposure of the cranial base was achieved while keeping the middle turbinate, uncinate process, ethmoid bulla, and middle meatus intact bilaterally. Successful resection of 2 consecutive cases of olfactory groove meningioma was performed using this approach. CONCLUSIONS: The endoscopic superior ethmoidal approach for anterior cranial base resection is a feasible and safe approach that maximizes preservation of the nasal structures while providing optimal access to the anterior skull base. It can be used in pathologies that involve the anterior cranial base and do not involve the nasal structures.

Asymmetric Meckel Cave Enlargement: A Potential Marker of PHACES Syndrome.

BACKGROUND AND PURPOSE: PHACES syndrome is a complex of morphologic abnormalities of unknown cause and includes posterior fossa abnormalities; head and neck infantile hemangiomas; arterial, cardiac, and eye anomalies; and sternal or abdominal wall defects. Accurate identification of the syndrome is important for optimal treatment. The purpose of this study was to investigate the incidence of asymmetric Meckel cave enlargement, a potential novel imaging marker, in a population of patients referred for evaluation of possible PHACES syndrome. MATERIALS AND METHODS: Eighty-five patients referred for neuroimaging evaluation of possible PHACES syndrome were identified and stratified on the basis of their ultimate clinical PHACES diagnosis categorization into PHACES, possible PHACES, or not PHACES. MR imaging studies were subsequently reviewed for the presence or absence of unilateral Meckel cave enlargement, with the reviewer blinded to the ultimate PHACES syndrome categorization. RESULTS: Twenty-five of 85 patients (29%) were ultimately categorized as having PHACES or possible PHACES according to consensus guidelines. Asymmetric Meckel cave enlargement was present in 76% (19/25) of these patients and in 82% (19/23) of only those patients with definite PHACES. This finding was present in none of the 60 patients determined not to have PHACES syndrome. In 7/19 patients (37%) with this finding, subtle MR imaging abnormalities consistent with PHACES were missed on the initial MR imaging interpretation. CONCLUSIONS: Asymmetric Meckel cave enlargement was a common feature of patients with PHACES in our cohort and may serve as a novel imaging marker. Increased awareness of this imaging feature has the potential to increase the diagnostic accuracy of PHACES.

How I do it: The expanded trans/supraorbital approach for large space-occupying lesions of the anterior fossa.

BACKGROUND: The supraorbital rim often interferes with the required upward movement of the instruments for resection of large frontal-lobe tumours through a classic supraorbital craniotomy. Here, we present the expanded trans/supraorbital approach to overcome these limitations. METHODS: After an eyebrow skin incision, a one-piece bone flap was created incorporating the orbital rim and roof. Basal extension of the craniotomy allowed for a better intracranial visualisation with improved manoeuvrability and angulation of the instruments without using brain retraction. CONCLUSIONS: This approach poses a feasible alternative to large frontal craniotomies for frontal-lobe tumours, for which a regular supraorbital craniotomy is insufficient.