Expertise in surgical neuro-oncology. Results of a survey by the EANS neuro-oncology section.

Introduction: Technical advances and the increasing role of interdisciplinary decision-making may warrant formal definitions of expertise in surgical neuro-oncology. Research question: The EANS Neuro-oncology Section felt that a survey detailing the European neurosurgical perspective on the concept of expertise in surgical neuro-oncology might be helpful. Material and methods: The EANS Neuro-oncology Section panel developed an online survey asking questions regarding criteria for expertise in neuro-oncological surgery and sent it to all individual EANS members. Results: Our questionnaire was completed by 251 respondents (consultants: 80.1%) from 42 countries. 67.7% would accept a lifetime caseload of >200 cases and 86.7% an annual caseload of >50 as evidence of neuro-oncological surgical expertise. A majority felt that surgeons who do not treat children (56.2%), do not have experience with spinal fusion (78.1%) or peripheral nerve tumors (71.7%) may still be considered experts. Majorities believed that expertise requires the use of skull-base approaches (85.8%), intraoperative monitoring (83.4%), awake craniotomies (77.3%), and neuro-endoscopy (75.5%) as well as continuing education of at least 1/year (100.0%), a research background (80.0%) and teaching activities (78.7%), and formal interdisciplinary collaborations (e.g., tumor board: 93.0%). Academic vs. non-academic affiliation, career position, years of neurosurgical experience, country of practice, and primary clinical interest had a minor influence on the respondents' opinions. Discussion and conclusion: Opinions among neurosurgeons regarding the characteristics and features of expertise in neuro-oncology vary surprisingly little. Large majorities favoring certain thresholds and qualitative criteria suggest a consensus definition might be possible.

The unilateral frontotemporal approach for large and giant olfactory groove meningioma: Experience with 18 consecutive patients.

AIM: Although the bifrontal approach used to be recommended for large olfactory groove meningioma (OGM), recent studies showed that large OGMs can also be resected safely via unilateral approaches. The present study aimed to discuss reasons for preferring a unilateral frontotemporal approach (UFTA), and the technical nuances and results of the UFTA, based on 18 cases. MATERIAL AND METHODS: The clinical and surgical data of patients who had been operated on for large (4-6cm) or giant (>6cm) OGM via a UFTA between 2011 and 2018 were retrospectively collected. RESULTS: In all, 18 patients were included. All tumors were compatible with a diagnosis of OGM in the light of peri-operative examinations. 11 cases (61%) were large and 7 (39%) giant OGM; mean diameter was 6.1cm (range, 4-10cm). Resection extent was Simpson grade II in 14 cases (78%), grade III in 1 (5%), and grade IV in 3 (17%). Sixteen cases (89%) had no peri-operative complications, while 2 patients (11%) showed cerebrospinal fluid leakage and hemorrhagic deposition in the surgical area. There were no new neurological deficits nor deaths. CONCLUSION: The UFTA for OGM is a relatively safe and effective approach, ensuring a high total removal rate with low mortality and morbidity. This study, with a reasonable number of patients, is one of the few in the literature on the outcome of this approach.

Does the third cervical vertebra need to be rimmed for odontoid screwing? A hypothetical study of anatomic landmarks.

BACKGROUND: The superoanterior portion of the third cervical vertebra may need to be rimmed during anterior odontoid screw fixation procedures. We, therefore, retrospectively evaluated radiological data to analyze the anatomical relation between the second and third cervical vertebra of the patients who were operated by an anterior cervical approach with respect to the question if odontoid screw fixation would have been possible without rimming or not. PATIENTS AND METHODS: Patients in whom the anterior approach for cervical disc prolapse and/or cervical stenosis was used between 2008 and 2010 were included in this study. The odontoid screw angle, and the angle between the lower second and the upper third cervical vertebral endplate were measured on intraoperative cervical lateral radiographs. If the screw line passed through the superior anterior portion of the third vertebral body, it was determined that the third cervical vertebra would have been needed to be rimmed if odontoid screwing would have been planned. RESULTS: 100 patients were included. There were 50 males and 50 females with a mean age of 47.9 years (mean ± SD: 47.9 ± 12.6 years). The mean odontoid screw angle, and the angle between the lower second and the upper third cervical vertebral endplate were 65.61° ± 3.75° and 15.24° ± 4.85° (nonparallel vertebral endplates only), respectively. The odontoid screw angle, in which the third cervical vertebra would not have been needed to be rimmed, was 63.87° ± 2.84°. In addition, the odontoid screw angle in which the third cervical vertebra would have been needed to be rimmed was 67.28° ± 3.77°. CONCLUSION: The odontoid screw angle may be easily measured on lateral radiographs. In cases in which the odontoid screw angle is 67.28° ± 3.77° or higher, the superoanterior portion of the third cervical vertebra would be needed to be rimmed for proper screw fixation of odontoid fractures.