Through the orbit and beyond: Current state and future perspectives in endoscopic orbital surgery on behalf of the EANS frontiers committee in orbital tumors and the EANS skull base section.

Introduction: Orbital surgery has always been disputed among specialists, mainly neurosurgeons, otorhinolaryngologists, maxillofacial surgeons and ophthalmologists. The orbit is a borderland between intra- and extracranial compartments; Krönlein's lateral orbitotomy and the orbitozygomatic infratemporal approach are the historical milestones of modern orbital-cranial surgery. Research question: Since its first implementation, endoscopy has significantly impacted neurosurgery, changing perspectives and approaches to the skull base. Since its first application in 2009, transorbital endoscopic surgery opened the way for new surgical scenario, previously feasible only with extensive tissue dissection. Material and methods: A PRISMA based literature search was performed to select the most relevant papers on the topic. Results: Here, we provide a narrative review on the current state and future trends in endoscopic orbital surgery. Discussion and conclusion: This manuscript is a joint effort of the EANS frontiers committee in orbital tumors and the EANS skull base section.

Anterolateral (juxtacondylar) approach with limited mastoidectomy to resect a jugular foramen meningioma.

BACKGROUND: The anterolateral (juxtacondylar) approach with limited mastoidectomy is a suitable option to expose the postero-inferior part of the jugular foramen (JF). It is particularly indicated for tumors extending in the neck beyond the jugular foramen, especially in those cases necessitating both neck control as well as control of the mastoid segment of facial nerve. METHOD: We describe here the steps to safely perform an anterolateral approach with mastoidectomy along with a brief description of its indications and limits. CONCLUSION: This approach represents a valid option to reach the JF. Its knowledge can improve the process of optimal approach selection when dealing with complex pathology involving the JF.

Five-year cause-specific survival after meningioma surgery. A nationwide population-based study.

BACKGROUND: Survival after meningioma surgery is often reported with inadequate allowance for competing causes of death. METHODS: We processed the French administrative medical database (Système National des Données de Santé: SNDS), to retrieve appropriate cases of surgically treated meningioma. Cause-specific survival in meningioma-related death was analyzed with the Fine & Gray (F&G) and cause-specific (CS) Cox models to identify associated factors. RESULTS: Five-year cumulative incidence was 2.85% for meningioma-related death and 6.3% for unrelated death (P<0.001). In the adjusted F&G and cause-specific Cox regression models for meningioma-related death, gender, age at surgery, co-morbidities, neurofibromatosis type 2, tumor insertion, tumor grade, cerebrospinal fluid (CSF) shunt insertion, preoperative embolization and need for redo surgery for recurrence emerged as independent prognostic factors of cause-specific survival (CSS) in meningioma-related death. CONCLUSION: At 5 years, the risk of meningioma-unrelated death was 2.21-fold greater than the risk of dying from the meningioma disease. Five-year CSS after meningioma surgery was greater in younger adults with benign spinal meningioma with low comorbidity. Those with malignant cranial tumor requiring preoperative embolization or CSF shunting for associated hydrocephalus and with severely degraded overall health status showed a significantly increased risk of meningioma-related death. Redo surgery for recurrence failed to improve the risk of meningioma-related death. We recommend the use of net survival methods such as CSS in meningioma studies where unrelated mortality is predominant, as this approach results in more accurate estimates of disease risk and associated predictors.

Surgical management of anterior clinoidal meningiomas: consensus statement on behalf of the EANS skull base section.

BACKGROUND: The optimal management of clinoidal meningiomas (CMs) continues to be debated. METHODS: We constituted a task force comprising the members of the EANS skull base committee along with international experts to derive recommendations for the management of these tumors. The data from the literature along with contemporary practice patterns were discussed within the task force to generate consensual recommendations. RESULTS AND CONCLUSION: This article represents the consensus opinion of the task force regarding pre-operative evaluations, patient's counselling, surgical classification, and optimal surgical strategy. Although this analysis yielded only Class B evidence and expert opinions, it should guide practitioners in the management of patients with clinoidal meningiomas and might form the basis for future clinical trials.

Vestibular schwannoma: care for soft tissues and subperineural dissection: how I do it.

BACKGROUND: Recognition of the right surgical cleavage plane of a vestibular schwannoma is mandatory to preserve the facial nerve function. METHOD: We describe here our surgical technique that is focused on soft tissues preservation and on subperineural dissection, avoiding direct exposure of the acoustico-facial complex in order to preserve facial nerve function. CONCLUSION: Soft tissue dissection helps in reducing patient's postoperative discomfort. Meticulously keeping a subperineural plan of dissection enables to preserve facial nerve function while offering satisfying resection rates.

Security and reliability of CUSTOMBONE cranioplasties: A prospective multicentric study.

BACKGROUND: Repairing bone defects generated by craniectomy is a major therapeutic challenge in terms of bone consolidation as well as functional and cognitive recovery. Furthermore, these surgical procedures are often grafted with complications such as infections, breaches, displacements and rejections leading to failure and thus explantation of the prosthesis. OBJECTIVE: To evaluate cumulative explantation and infection rates following the implantation of a tailored cranioplasty CUSTOMBONE prosthesis made of porous hydroxyapatite. One hundred and ten consecutive patients requiring cranial reconstruction for a bone defect were prospectively included in a multicenter study constituted of 21 centres between December 2012 and July 2014. Follow-up lasted 2 years. RESULTS: Mean age of patients included in the study was 42±15 years old (y.o), composed mainly by men (57.27%). Explantations of the CUSTOMBONE prosthesis were performed in 13/110 (11.8%) patients, significantly due to infections: 9/13 (69.2%) (p<0.0001), with 2 (15.4%) implant fracture, 1 (7.7%) skin defect and 1 (7.7%) following the mobilization of the implant. Cumulative explantation rates were successively 4.6% (SD 2.0), 7.4% (SD 2.5), 9.4% (SD 2.8) and 11.8% (SD 2.9%) at 2, 6, 12 and 24 months. Infections were identified in 16/110 (14.5%): 8/16 (50%) superficial and 8/16 (50%) deep. None of the following elements, whether demographic characteristics, indications, size, location of the implant, redo surgery, co-morbidities or medical history, were statistically identified as risk factors for prosthesis explantation or infection. CONCLUSION: Our study provides relevant clinical evidence on the performance and safety of CUSTOMBONE prosthesis in cranial procedures. Complications that are difficulty incompressible mainly occur during the first 6 months, but can appear at a later stage (>1 year). Thus assiduous, regular and long-term surveillances are necessary.

Petroclival meningiomas: update of current treatment and consensus by the EANS skull base section.

BACKGROUND: The optimal management of petroclival meningiomas (PCMs) continues to be debated along with several controversies that persist. METHODS: A task force was created by the EANS skull base section along with its members and other renowned experts in the field to generate recommendations for the management of these tumors. To achieve this, the task force reviewed in detail the literature in this field and had formal discussions within the group. RESULTS: The constituted task force dealt with the existing definitions and classifications, pre-operative radiological investigations, management of small and asymptomatic PCMs, radiosurgery, optimal surgical strategies, multimodal treatment, decision-making, and patient's counselling. CONCLUSION: This article represents the consensually derived opinion of the task force with respect to the management of PCMs.

Endoscope-assisted anterolateral approach to a recurrent cervical spinal chordoma.

BACKGROUND: The anterolateral approach (ALA) enables to access the craniovertebral junction (CVJ), lower and middle clivus, jugular foramen, and cervical spine from a lateral perspective. It is particularly indicated when dealing with extradural bone tumors. Other rare indications are represented by spondylotic myeloradiculopathy and vascular diseases. METHOD: We describe here the steps to safely perform an anterolateral approach along with a brief description of its indications and limits. CONCLUSION: ALA represents a valid option to treat cervical spine and CVJ bone tumors such as chordomas. Its knowledge can improve the process of approach selection when dealing with such complex cases.

Best practices for the management of local-regional recurrent chordoma: a position paper by the Chordoma Global Consensus Group.

Chordomas are rare, malignant bone tumors of the skull-base and axial skeleton. Until recently, there was no consensus among experts regarding appropriate clinical management of chordoma, resulting in inconsistent care and suboptimal outcomes for many patients. To address this shortcoming, the European Society of Medical Oncology (ESMO) and the Chordoma Foundation, the global chordoma patient advocacy group, convened a multi-disciplinary group of chordoma specialists to define by consensus evidence-based best practices for the optimal approach to chordoma. In January 2015, the first recommendations of this group were published, covering the management of primary and metastatic chordomas. Additional evidence and further discussion were needed to develop recommendations about the management of local-regional failures. Thus, ESMO and CF convened a second consensus group meeting in November 2015 to address the treatment of locally relapsed chordoma. This meeting involved over 60 specialists from Europe, the United States and Japan with expertise in treatment of patients with chordoma. The consensus achieved during that meeting is the subject of the present publication and complements the recommendations of the first position paper.

Axono-cortical evoked potentials: A proof-of-concept study.

Awake surgery is currently considered the best method to tailor intraparenchymatous resections according to functional boundaries. However, the exact mechanisms by which electrical stimulation disturbs behavior remain largely unknown. In this case report, we describe a new method to explore the propagation toward cortical sites of a brief pulse applied to an eloquent white matter pathway. We present a patient, operated on in awake condition for removal of a cavernoma of the left ventral premotor cortex. At the end of the resection, the application of 60Hz stimulation in the white matter of the operculum induced anomia. Stimulating the same site at a frequency of 1Hz during 70seconds allowed to record responses on electrodes put over Broca's area and around the inferior part of central sulcus. Axono-cortical evoked potentials were then obtained by averaging unitary responses, time-locked to the stimulus. We then discuss the origin of these evoked axono-cortical potentials and the likely pathway connecting the stimulation site to the recorded cortical sites.

Comparison of cardiac output measured by oesophageal Doppler ultrasonography or pulse pressure contour wave analysis.

BACKGROUND: Maintaining adequate organ perfusion during high-risk surgery requires continuous monitoring of cardiac output to optimise haemodynamics. Oesophageal Doppler Cardiac Output monitoring (DCO) is commonly used in this context, but has some limitations. Recently, the cardiac output estimated by pulse pressure analysis- (PPCO) was developed. This study evaluated the agreement of cardiac output variations estimated with 9 non-commercial algorithms of PPCO compared with those obtained with DCO. METHODS: High-risk patients undergoing neurosurgery were monitored with invasive blood pressure and DCO. For each patient, 9 PPCO algorithms and DCO were recorded before and at the peak effect for every haemodynamic challenge. RESULTS: Sixty-two subjects were enrolled; 284 events were recorded, including 134 volume expansions and 150 vasopressor boluses. Among the 9 algorithms tested, the Liljestrand-Zander model led to the smallest bias (0.03 litre min(-1) [-1.31, +1.38] (0.21 litre min(-1) [-1.13; 1.54] after volume expansion and -0.13 litre min(-1) [-1.41, 1.15] after vasopressor use). The corresponding percentage of the concordance was 91% (86% after volume expansion and 94% after vasopressor use). The other algorithms, especially those using the Winkessel concept and the area under the pressure wave, were profoundly affected by the vasopressor. CONCLUSIONS: Among the 9 PPCO algorithms examined, the Liljestrand-Zander model demonstrated the least bias and best limits of agreement, especially after vasopressor use. Using this particular algorithm in association with DCO calibration could represent a valuable option for continuous cardiac output monitoring of high risk patients. CLINICAL TRIAL REGISTRATION: Comité d'éthique de la Société de Réanimation de Langue Française No. 11-356.

Expert-validated CSF segmentation of MNI atlas enhances accuracy of virtual glioma growth patterns.

Biomathematical modeling of glioma growth has been developed to optimize treatments delivery and to evaluate their efficacy. Simulations currently make use of anatomical knowledge from standard MRI atlases. For example, cerebrospinal fluid (CSF) spaces are obtained by automatic thresholding of the MNI atlas, leading to an approximate representation of real anatomy. To correct such inaccuracies, an expert-revised CSF segmentation map of the MNI atlas was built. Several virtual glioma growth patterns of different locations were generated, with and without using the expert-revised version of the MNI atlas. The adequacy between virtual and radiologically observed growth patterns was clearly higher when simulations were based on the expert-revised atlas. This work emphasizes the need for close collaboration between clinicians and researchers in the field of brain tumor modeling.

[Chordoma]. / Les chordomes.

PURPOSES: To review in the literature, all the epidemiological, clinical, radiological, histological and therapeutic data regarding chordomas as well as various notochordal entities: ecchordosis physaliphora, intradural and intraparenchymatous chordomas, benign notochordal cell tumors, parachordomas and extra-axial chordomas. To identify different types of chordomas, including familial forms, associations with tuberous sclerosis, Ollier's disease and Maffucci's syndrome, forms with metastasis and seeding. To assess the recent data regarding molecular biology and progress in targeted therapy. To compare the different types of radiotherapy, especially protontherapy and their therapeutic effects. To review the largest series of chordomas in their different localizations (skull base, sacrum and mobile spine) from the literature. MATERIALS: The series of 136 chordomas treated and followed up over 20 years (1972-2012) in the department of neurosurgery at Lariboisière hospital is reviewed. It includes: 58 chordomas of the skull base, 47 of the craniocervical junction, 23 of the cervical spine and 8 from the lombosacral region. Similarly, 31 chordomas in children (less than 18 years of age), observed in the departments of neurosurgery of les Enfants-Malades and Lariboisière hospitals, are presented. They were observed between 1976 and 2010 and were located intracranially (n=22 including 13 with cervical extension), 4 at the craniocervical junction level and 5 in the cervical spine. METHODS: In the entire Lariboisière series and in the different groups of localization, different parameters were analyzed: the delay of diagnosis, of follow-up, of occurrence of metastasis, recurrence and death, the number of primary patients and patients referred to us after progression or recurrence and the number of deaths, recurrences and metastases. The influence of the quality of resection (total, subtotal and partial) on the prognosis is also presented. Kaplan-Meier actuarial curves of overall survival and disease free survival were performed in the entire series, including the different groups of localization based on the following 4 parameters: age, primary and secondary patients, quality of resection and protontherapy. In the pediatric series, a similar analysis was carried-out but was limited by the small number of patients in the subgroups. RESULTS: In the Lariboisière series, the mean delay of diagnosis is 10 months and the mean follow-up is 80 months in each group. The delay before recurrence, metastasis and death is always better for the skull base chordomas and worse for those of the craniocervical junction, which have similar results to those of the cervical spine. Similar figures were observed as regards the number of deaths, metastases and recurrences. Quality of resection is the major factor of prognosis with 20.5 % of deaths and 28 % of recurrences after total resection as compared to 52.5 % and 47.5 % after subtotal resection. This is still more obvious in the group of skull base chordomas. Adding protontherapy to a total resection can still improve the results but there is no change after subtotal resection. The actuarial curve of overall survival shows a clear cut in the slope with some chordomas having a fast evolution towards recurrence and death in less than 4 years and others having a long survival of sometimes more than 20 years. Also, age has no influence on the prognosis. In primary patients, disease free survival is better than in secondary patients but not in overall survival. Protontherapy only improves the overall survival in the entire series and in the skull base group. Total resection improves both the overall and disease free survival in each group. Finally, the adjunct of protontherapy after total resection is clearly demonstrated. In the pediatric series, the median follow-up is 5.7 years. Overall survival and disease free survival are respectively 63 % and 54.3 %. Factors of prognosis are the histological type (atypical forms), localization (worse for the cervical spine and better for the clivus) and again it will depend on the quality of resection. CONCLUSIONS: Many different pathologies derived from the notochord can be observed: some are remnants, some may be precursors of chordomas and some have similar features but are probably not genuine chordomas. To-day, immuno-histological studies should permit to differentiate them from real chordomas. Improving knowledge of molecular biology raises hopes for complementary treatments but to date the quality of surgical resection is still the main factor of prognosis. Complementary protontherapy seems useful, especially in skull base chordomas, which have better overall results than those of the craniocervical junction and of the cervical spine. However, we are still lacking an intrinsic marker of evolution to differentiate the slow growing chordomas with an indolent evolution from aggressive types leading rapidly to recurrence and death on which more aggressive treatments should be applied.

Radionecrosis of the frontal lobe as a consequence of malignant ethmoid tumor management: incidence, diagnosis, risk factors, prevention and management.

Malignant ethmoid tumors are treated by surgery followed by radiotherapy. This study aimed to evaluate the incidence, risk factors and outcome of radionecrosis of frontal lobe and determine preventive measures. Retrospective study of ethmoid malignancies treated from 2000 to 2011. All patients underwent surgery with/without anterior skull base resection using endoscopic or external approaches followed by irradiation (mean dose 64 Gy). Median follow-up was 50 months. Eight of 50 patients (16 %) presented with fronto-basal radionecrosis, connected to duraplasty, with a latent interval of 18.5 months. Although asymptomatic in six, radionecrosis triggered seizures and required surgery in two cases. Survival was not impacted. Risk factors included dyslipidemia, occurrence of epilepsy and dural resection. Radionecrosis may result from the combination of anterior skull base resection and radiotherapy for the treatment of ethmoid malignancies. Preventive measures rely on improving the duraplasty and optimization of the Gy-dose delivery.

Anterior trans-frontal endoscopic management of colloid cyst: an effective, safe, and elegant way of treatment. Case series and technical note from a multicenter prospective study.

Different management options are available for the treatment of colloid cysts. Goals of those procedures are to achieve a complete resection avoiding potential long-term recurrence along with CSF pathways restoration with minimal morbidity and mortality. The two main surgical options are endoscopic resection or direct removal by either transfrontal or transcallosal approach. The efficacy of endoscopic technique to achieve gross total colloid cyst excision has been well documented. In the present study, authors describe a series of 29 patients who underwent surgery by a variation of the standard worldwide implemented endoscopic technique. Using a more anterior approach, it is easier to reach the roof of the cyst, its possible adherences with the tela choroidea, plexus, and the internal cerebral veins. The described approach has shown to be safe, quick, and very effective with a total cyst removal rate of 86.2%.

[Giant cell tumor of the C2 colonized by an aneurismal bone cyst. Report of case]. / Tumeur à cellules géantes de C2 colonisée par un kyste anévrismal. À propos d'un cas.

Giant cell tumor is colonized by aneurismal bone cyst in only 15% of cases and cervical localisation accounts for less than 1% of giant cell tumors. We are reporting a rare case of a C2 hypervascularized giant cell tumor colonized by an aneurismal bone cyst treated with an effective preoperative Onyx embolization followed by a full tumor resection. The patient experienced a moderate cervical spine injury 2 months prior admission followed by a progressive stiff neck and cervicalgia. CT and MRI identified a lytic lesion of the body and lateral masses of the C2 with encasement of both vertebral arteries. The angiography showed a hypervascularization of the lesion from the vertebral and external carotid arteries as well as a thrombosis of the V3 segment of the right vertebral artery at the C1 level. A posterior occipito-C3/C4 fixation and a tumor biopsy were performed. Histopathological examination concluded to a giant cell tumor colonized by an aneurismal bone cyst. Three weeks later, the patient developed a right upper extremity deficit. The MRI showed an increased C1-C2 stenosis and an increase of the hypervascularization. Three sessions of embolization by the onyx were performed. During surgery a near total tumor devascularisation was observed and a complete resection of the tumor was achieved through an anterolateral approach. Reconstruction consisted of a cementoplasty of the C2 body and odontoïd process with an anterior C3-prosthesis plate. The postoperative course was uneventful.

Glioblastoma multiforme presenting with ischemic stroke: case report and review of the literature.

A 58-year-old woman presented with acute onset of global aphasia. Imaging studies revealed a left frontotemporal enhancing tumor and ischemic stroke in the territory of the middle cerebral artery. The patient was operated on, and the diagnosis of glioblastoma multiforme was confirmed. At the time of surgery, several branches of the left middle cerebral artery were found embedded in the tumor. One branch, which was infiltrated by tumor and completely occluded, was resected to achieve complete resection. Postoperatively, the stroke area within the middle cerebral artery territory increased, together with worsening of the patient's clinical status, thus requiring urgent decompressive craniectomy. Thereafter, the patient gradually improved, and received radiation therapy and chemotherapy with no recurrence after 24 months of follow-up. To our knowledge, glioblastomas presenting with ischemic stroke are rare, and such patients should be considered to be at high surgical risk.

[Descriptive anatomy of the orbit]. / Anatomie descriptive de l'orbite.

Anatomical description of the orbit is essential for an accurate understanding of its related tumoral pathologies. Numerous cadaveric pictures illustrate this chapter, which contains the description of the bony walls of the orbit and its muscular nerve, and vascular structures.