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.

Spinal metastases of bronchopulmonary cancer: Role of spinal surgery and value of prognostic scores (Modified Tokuhashi and Tomita).

INTRODUCTION: Bone metastasis is frequent in bronchopulmonary cancer. We report a series of 52 patients, and analyze indications and the efficacy of surgery. MATERIALS AND METHODS: We retrospectively studied the records of 52 patients operated on for spinal metastases of bronchopulmonary cancer over a 6-year period from January 2009 to December 2014 in the neurosurgery department of the North Hospital of Marseille, France. RESULTS: Mean age was 63.6years; with a sex ratio of 3:1 (M:F). Spinal pain associated with vertebral fracture and spinal cord compression was the most frequent clinical presentation (59.6%). SINS score was≥7 in 78.9% of cases. Karnofski Performance Status was average in 67.4% of cases. Predicted survival beyond 12months was zero according to the modified Tokuhashi score. The surgical indication was essentially palliative. Evolution showed regression of pain in 84.6% of cases, and stabilization and improvement in motor deficit in 80.6%. Median postoperative survival was 16months. CONCLUSION: Our results highlight the interest of surgery for pain relief, spinal stabilization and improvement in neurological function in patients with spinal metastases of bronchopulmonary cancer, and the unreliability of predictive survival scores.

Results of a French pilot database of standard of care of chronic subdural hematoma.

BACKGROUND: A registry of chronic subdural hematoma does not exist in France yet. OBJECTIVE: To present a monocentric pilot project of a French registry of surgical management of chronic subdural hematoma. METHOD: A monocentric pseudonymized formal database was created. From May 2020 to May 2021, all patients undergoing surgical evacuation of chronic subdural hematoma were entered into the database. RESULTS: One hundred and twenty four surgeries from 113 patients were entered in the database. Patients' demographic and surgical data as well as follow-up are described. CONCLUSION: A local database is easy to implement. We propose a national registry of chronic subdural hematoma management.

T1 Mapping for Microstructural Assessment of the Cervical Spinal Cord in the Evaluation of Patients with Degenerative Cervical Myelopathy.

BACKGROUND AND PURPOSE: Although current radiologic evaluation of degenerative cervical myelopathy by conventional MR imaging accurately demonstrates spondylosis or degenerative disc disease causing spinal cord dysfunction, conventional MR imaging still fails to provide satisfactory anatomic and clinical correlations. In this context, we assessed the potential value of quantitative cervical spinal cord T1 mapping regarding the evaluation of patients with degenerative cervical myelopathy. MATERIALS AND METHODS: Twenty patients diagnosed with mild and moderate-to-severe degenerative cervical myelopathy and 10 healthy subjects were enrolled in a multiparametric MR imaging protocol. Cervical spinal cord T1 mapping was performed with the MP2RAGE sequence procedure. Retrieved data were processed and analyzed regarding the global spinal cord and white and anterior gray matter on the basis of the clinical severity and the spinal canal stenosis grading. RESULTS: Noncompressed levels in healthy controls demonstrated significantly lower T1 values than noncompressed, mild, moderate, and severe stenotic levels in patients. Concerning the entire spinal cord T1 mapping, patients with moderate-to-severe degenerative cervical myelopathy had higher T1 values compared with healthy controls. Regarding the specific levels, patients with moderate-to-severe degenerative cervical myelopathy demonstrated a T1 value increase at C1, C7, and the level of maximal compression compared with healthy controls. Patients with mild degenerative cervical myelopathy had lower T1 values than those with moderate-to-severe degenerative cervical myelopathy at the level of maximal compression. Analyses of white and anterior gray matter confirmed similar results. Strong negative correlations between individual modified Japanese Orthopaedic Association scores and T1 values were also observed. CONCLUSIONS: In this preliminary study, 3D-MP2RAGE T1 mapping demonstrated increased T1 values in the pathology tissue samples, with diffuse medullary alterations in all patients with degenerative cervical myelopathy, especially relevant at C1 (nonstenotic level) and at the maximal compression level. Encouraging correlations observed with the modified Japanese Orthopaedic Association score make this novel approach a potential quantitative biomarker related to clinical severity in degenerative cervical myelopathy. Nevertheless, patients with mild degenerative cervical myelopathy demonstrated nonsignificant results compared with healthy controls and should now be studied in multicenter studies with larger patient populations.

Sustainable neurosurgical training around the globe. A review and outline.

Sharing an equal and quality neurosurgical training across the globe without exclusion may seem utopian. However, such training is possible through educational opportunities and the ongoing digital revolution. The aim is to present the current state of neurosurgery training and education methods indicating strengths, weaknesses and opportunities. The thoughts, comments and suggestions of the authors are based on their academic experiences, training missions around the world and particularly in low- and middle-income countries by pointing out the French experience. The learning must be interactive and programmed over time, integrating varied courses and activities. Virtual reality and neurosurgical simulation need to be developed. The content of the teaching including e-learning must be evidence-based and peer-reviewed. Pedagogical training of trainers is fundamental. It is critical to evaluate the training under real working conditions. The optimization of human resources should create economies of scale that would attenuate the financial burden. The commitment of the teams, tutoring are success factors.

The presigmoid retrolabyrinthine approach: Technical note.

BACKGROUND: The retrolabyrinthine approach is classified among the posterior petrosectomies. Its goal is to achieve an enlarged mastoidectomy while sparing the intrapetrous neurotologic structures in order to offer maximal exposure of the posterior cerebellopontine angle compound. METHODS: The stages of the procedure are subsequently the skeletonization of the sigmoid sinus, wide opening of the mastoid antrum and exposure of the semicircular canals. We present herein the technique, indications and limitations of the retrolabyrinthine approach. CONCLUSION: The retrolabyrinthine approach is a demanding technique. Nowadays the retrolabyrinthine approach is routinely combined to additional resections of the petrous bone, so-called "combined petrosectomies", to target the jugular foramen or the petroclival area.

A snapshot of European neurosurgery December 2019 vs. March 2020: just before and during the Covid-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis. METHODS: We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days. RESULTS: We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs. CONCLUSION: Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent European countries.

Reform of the 3rd cycle in surgery training.

The main objectives of the reform of the 3rd cycle of medical studies in France that was instituted in 2017 after eight years of preparation, are to train future specialists in a consistent and equitable fashion and to replace the previous time-based qualification by training based on the progressive acquisition of skills. This reform was an opportunity for the 13 different French surgical specialty Colleges involved to share reflections on what a surgeon actually was and to define training in surgical sub-specialties. The current reform is well adapted to these specifications and has fostered training models that are consistent with each other. This article discusses the historical construction of this reform, what will change in the training of future surgeons, as well as some points that warrant caution. The third cycle reform has also triggered a reform of the second cycle, which is expected to come into force for the 2020 academic year. Its objective will be to eliminate the guillotine effect created by the National Classifying Examinations and to allow students to better understand and test their desire and skills for a given specialty. It will be up to these same surgical Colleges to determine how to do this for the sub-specialties of the "surgery" discipline.

Functional outcome 1 year after aneurysmal subarachnoid hemorrhage due to ruptured intracranial aneurysm in elderly patients.

BACKGROUND: Population aging raises questions about extending treatment indications in elderly patients with aneurysmal subarachnoid hemorrhage (aSAH). We therefore assessed functional status 1 year after treatment. METHODS: This study involved 310 patients, aged over 70 years, with ruptured brain aneurysm, enrolled between 2008 and 2014 in a prospective multicentre trial (FASHE study: NCT00692744) but considered unsuitable for randomisation and therefore analysed in the observational arms of the study: endovascular occlusion (EV), microsurgical exclusion (MS) and conservative treatment. The aims were to assess independence, cognition, autonomy and quality of life (QOL) at 1 year post-treatment, using questionnaires (MMSE, ADLI, IADL, EORTC-QLQ-C30) filled in by independent nurses after discharge. RESULTS: The 310 patients received the following treatments: 208 underwent EV (67.1%), 54 MS (17.4%) and 48 were conservatively managed (15.5%). At 1 year, independence rates for patients admitted with good clinical status (WFNS I-III) were, according to the aneurysm exclusion procedure (EV, MS or conservative), 58.9%, 50% and 12.1% respectively. MMSE score was pathological in 26 of the 112 EV patients (23.2%), 10 of the 25 MS patients (40%) and 4 of the 9 patients treated conservatively (44%), without any statistically significant difference [Pearson's Chi2 test, F ratio=4.29; P=0.11]. Regarding QoL, overall score was similar between the EV and MS cohorts, but significantly lower with conservative treatment. CONCLUSION: Elderly patients in good clinical condition with aSAH should be treated regardless of associated comorbidities. Curative treatment (EV or MS) reduced mortality without increasing dependence, in comparison with conservative treatment.

Toward the development of 3-dimensional virtual reality video tutorials in the French neurosurgical residency program. Example of the combined petrosal approach in the French College of Neurosurgery.

BACKGROUND: The present study developed 3D video tutorials with commentaries, using virtual reality headsets (VRH). VRHs allow 3D visualization of complex anatomy from the surgeon's point of view. Students can view the surgery repeatedly without missing the essential steps, simultaneously receiving advice from a group of experts in the field. METHODS: A single-center prospective study assessed surgical teaching using 3D video tutorials designed for French neurosurgery and ENT residents participating in the neuro-otology lateral skull-base workshop of the French College of Neurosurgery. At the end of the session, students filled out an evaluation form with 5-point Likert scale to assess the teaching and the positive and negative points of this teaching tool. RESULTS: Twenty-two residents in neurosurgery (n=17, 81.0%) and ENT (n=5) were included. Eighteen felt that the 3D video enhanced their understanding of the surgical approach (81.8%). Fifteen (68.2%) thought the video provided good 3D visualization of anatomical structures and 20 that it enabled better understanding of anatomical relationships (90.9%). Most students had positive feelings about ease of use and their experience of the 3D video tutorial (n=14, 63.6%). Twenty (90.9%) enjoyed using the video. Twelve (54.5%) considered that the cadaver dissection workshop was more instructive. CONCLUSIONS: 3D video via a virtual reality headset is an innovative teaching tool, approved by the students themselves. A future study should evaluate its long-term contribution, so as to determine its role in specialized neurosurgery and ENT diploma courses.

Long term surgical results of 154 petroclival meningiomas: A retrospective multicenter study.

BACKGROUND: Outcomes of petroclival meningiomas (PCM) (morbidity, permanent cranial nerves deficit, tumor removal and recurrence) are inconsistent in the literature, making it a challenge to predict surgical morbidity. METHODS: A multicenter study of patients with PCMs larger than 2.5cm between 1984 and 2017 was conducted. The authors retrospectively reviewed the patients' medical records, imaging studies and pathology reports to analyze presentation, surgical approach, neurological outcomes, complications, recurrence rates and predictive factors. RESULTS: There were 154 patients. The follow-up was 76.8 months on average (range 8-380 months). Gross total resection (GTR) was achieved in 40 (26.0%) patients, subtotal resection (STR) in 101 (65.6%), and partial resection in 13 (8.3%). Six (2.6%) perioperative deaths occurred. The 5-year, 10-year and 15-year progression-free survival (PFS) of GTR and STR with radiation therapy (RT) was similar (100%, 90% and 75%). PFS of STR without adjuvant radiation was associated with progression in 71%, 51% and 31%, respectively. Anterior petrosectomy and combined petrosectomy were associated with higher postoperative CN V and CN VI deficits compared to the retrosigmoid approach. The latter had a significantly higher risk of CN VII, CN VIII and LCN deficit. Temporal lobe dysfunction (seizure and aphasia) were significantly associated with the anterior petrosectomy approach. CONCLUSIONS: Our study shows that optimal subtotal resection of PCMs associated with postoperative RT or stereotactic radiosurgery results in long-term tumor control to equivalent radical surgery. Case selection and appropriate intraoperative judgement are required to reduce the morbidity.

Chiari malformations in adults: A single center surgical experience with special emphasis on the kinetics of clinical improvement.

BACKGROUND: The Chiari malformation type I (CM-I) is the most commonly found type in adults. The efforts to further improve the treatment offered for these malformations are hampered by the existence of controversial methods and the absence of a uniform scoring system to evaluate clinical outcomes. OBJECTIVES: The goal of our study is to analyze the clinical and radiological data concerning patients operated for CM and to expose surgical techniques. PATIENTS AND TREATMENT: This is a retrospective study concerning patients of more than 16 years of age, operated on (from 2000 to 2016) in our institution. These patients underwent bony decompression of the cervico-occipital junction, with a duraplasty enlargement. Clinical and radiological follow-up was assessed sequentially. RESULTS: The mean age of patients included in this study was 39. Headaches (n=19) and sensory disturbances (n=17) were the most common presenting complaints. Furthermore, syringomyelia symptoms were present in 34.5% of the cases (n=10). Twenty-three patients displayed a Chiari malformation of type I (79.3%), and six patients were classified as Chiari malformation type I.5 (20.7%). A syringomyelia was present in 58.6% of the cases (n=17). The postoperative complications that were encountered were: one case of pseudo-meningocele, two cases of cerebrospinal fluid leakage, two cases of meningitis, and one case of delayed wound healing. The mean follow-up period was 18 months, which showed beneficial outcomes in 82.8% of the cases (20.7% cured, and 62.1% improved) and an unfavorable outcome in 17.2% of the cases (13.8% stable patients and 3.4% worsened outcomes). Syringomyelia symptoms were improved in 60% of the patients. Among the patients who presented without a syrinx, 82.3% had good outcomes; and those who presented with a syrinx, 83.4% had good outcomes. Symptoms improved for 69% of patients within 3 months. CONCLUSION: An optimal craniocervical osteo-dural decompression plus duraplasty offered early and sustainable good clinical results in symptomatic CM-I and CM-I.5 patients.

A randomized controlled study assessing outcome, cognition, autonomy and quality of life in over 70-year-old patients after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Current aging of the population with good physiological status and the increasing incidence of subarachnoid hemorrhage (SAH) in elderly patients has enhanced the benefit of treatment in terms of independence and long-term quality of life (QoL). METHODS: From November 1, 2008 to October 30, 2012, 351 patients aged 70 years or older with aneurysmal SAH underwent adapted treatment: endovascular coiling (EV) for 228 (65%) patients, microsurgical clipping (MS) for 75 (29.3%) or conservative treatment for 48 (13.7%). Forty-one of these were randomized to EV (n=20) or to MS (n=21). The objectives were to determine the proportion of patients with modified Rankin Scale score≤2 (independence) at 1 year, and, secondarily, to compare cognitive function on the Mini-Mental State Examination (MMSE), autonomy on the Activities of Daily Living Index (ADLI) and Instrumental Activities of Daily Living scale (IADL), and QoL, in the prospective and randomized arms, at 1 year. RESULTS: At 1 year, with 1 loss to follow-up in the EV arm, 11 patients (55%) were independent after EV occlusion and 8 (38.1%) after MS exclusion, without significant difference (P=0.29). Mortality was higher after MS during the first 2 postoperative months, and thereafter the difference between MS and EV ceased to be significant. Cognitive function and autonomy scores were similar in both arms. CONCLUSION: In elderly patients treated for aneurysmal SAH, approximately 50% were independent at 1 year, with conserved cognition and autonomy. EV and MS are valid procedures in this population, with similar results at 1 year in terms of independence, cognition, autonomy, and QoL.

Rupture limit evaluation of human cerebral aneurysms wall: Experimental study.

BACKGROUND AND PURPOSE: Rupture risk of intracranial aneurysms is a major issue for public healthcare. A way to obtain an individual rupture risk assessment is a main objective of many research teams in the world. For many years, we have investigated the relationship between the mechanical properties of aneurysm wall tissues and the rupture risk. In this work, we try to go further and investigate rupture limit values. METHODS: Following surgical clipping, a specific conservation protocol was applied to aneurysmal tissues in order to preserve their mechanical properties. Thirty-nine intracranial aneurysms (27 females, 12 males) were tested using a uniaxial tensile test machine under physiological conditions, temperature, and saline isotonic solution. These represented 24 unruptured and 15 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a Yeoh hyperelastic model with 2 parameters. Moreover, uniaxial tensile tests were conducted until rupture of samples to obtain values of stress and strain rupture limit. RESULTS: The significant parameter a C2 of the hyperelastic Yeoh model, allowed us to classify samples' rigidity following the terminology we adopted in previous papers (Costalat et al., 2011; Sanchez et al., 2013): Soft, Stiff and Intermediate. Moreover, strain/stress rupture limit values were gathered and analyzed thanks to the tissue rigidity, the status of the aneurysm (initially ruptured or unruptured) and the gender of the patient. CONCLUSION: Strain rupture limit was found quite stable around 20% and seems not to be correlated with the status of the aneurysm (initially ruptured or unruptured), neither with the gender of the patient. However, stretch and stress rupture limit seems not to be independent on the rigidity. The study confirms that ruptured aneurysms mainly present a soft tissue and unruptured aneurysms present a stiff material.

Delayed hemorrhagic complication after complete embolization of a brain arteriovenous malformation.

Endovascular embolization is an essential therapeutic approach in the multidisciplinary management of cerebral arteriovenous malformations (AVM). However, it rarely occludes the AVM in its entirety. It is often combined with surgery or stereotactic radiosurgery. The aim of embolization is to reduce the size of the nidus and the intra-nidal flow in order to facilitate the microsurgical or the radiosurgical procedure. We report the case of a 61-year-old patient with a right frontal hemorrhagic AVM treated with complete embolization in a single session. Initially, a surgical procedure for excision of the AVM was scheduled 24hours post-embolization. This surgery was canceled due to a good angiographic result of the embolization. Eight days post-embolization, there was a massive re-bleed of the AVM which justified emergency surgical management. This case illustrates a delayed post-embolization hemorrhagic complication of an occluded AVM and prompts a review of the therapeutic strategy of the cerebral AVM to select the most effective and least morbid procedure or combination of procedures.

Long-term results of Gamma-knife stereotactic radiosurgery for vestibular schwannomas in patients with type 2 neurofibromatosis.

INTRODUCTION: The aim of this study was to analyze the long-term results of Gamma-knife radiosurgery treatment of vestibular schwannomas in type 2 neurofibromatosis patients. MATERIALS AND METHODS: A cohort of 129 treatments for vestibular schwannomas in 103 patients was selected from a prospectively-maintained clinical database. Tumor control was assessed by volumetric analysis of the tumor at the last follow-up. Any need of a further procedure such as microsurgical removal or second treatment was regarded as a failure of tumor control. Hearing function was assessed based on Gardner-Robertson classification. Progression-free survival and functional hearing preservation rates were estimated using the Kaplan-Meier method. RESULTS: The median age at treatment was 34 years with no gender predominance. The median tumor volume was 1.5cm3. At a median clinical follow-up of 5.9 years, five patients had died, four underwent a second radiosurgical procedure and eight underwent microsurgical resection. Progression-free survival was 88 and 75% respectively at 5 and 10 years. Hearing was considered serviceable in 70 ears and remained functional in 28 ears. Kaplan-Meier estimates for 5 and 10 years functional hearing was 47 and 34%, respectively. Three patients developed new facial nerve palsy after radiosurgery at 15 days, 6 and 19 months respectively and only one partially recovered. Five patients complained of a subjective instability worsening. Four cases developed trigeminal neuropathy. No predictive factors were found to be statistically correlated with a better hearing outcome or an improved tumor growth control. CONCLUSION: Results prove less satisfying than in sporadic unilateral schwannomas. However, the lower rate of mortality and morbidity compared with microsurgical resection may support a proactive role of Gamma-knife in this pathology.

Extradural resection of the anterior clinoid process: How I do it.

BACKGROUND: The anterior clinoid process shares a close relationship with the optic canal, the internal carotid artery, the superior orbital fissure and the cavernous sinus. These structures may be involved in diseases whose surgical exposure requires prior clinoid process resection. METHOD: Based on operative cases we describe the different steps of this surgical technique and illustrate our surgical procedure with a video. Dividing the orbito-temporal periosteal fold is a key-step in order to optimize the elevation of the periosteal dural layer at the level of the superior orbital fissure to expose the contours of the anterior clinoid process. The clinoid tip is removed after "debulking" the bony content inside the anterior clinoid process in order to leave only a thin shell of bony contour. The bony shell is then detached from the dura, twisted and pulled out. The indications and limitations of the technique are presented. CONCLUSION: The extradural approach of the anterior clinoid process totally provides a full resection of the anterior clinoid process and safety for the paraclinoid space structures. Meticulous stepwise bony resection and optimized dura opening contribute to reduce the risk inherent to this technique.