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OBJECTIVE Spontaneous CSF leaks into the anterior skull base nasal sinuses are often associated with meningoencephaloceles and occur in patients with idiopathic intracranial hypertension (IIH). Endonasal endoscopic repair has become the primary method of choice for repair. The authors sought to evaluate the success rate of endoscopic closure and to identify predictive factors for CSF leak recurrence. METHODS A consecutive series of endonasally repaired anterior skull base meningoencephaloceles was drawn from a prospectively acquired database. Lumbar punctures were not performed as part of a treatment algorithm. All patients had at least 5 months of follow-up. Chart review and phone calls were used to determine the timing and predictors of recurrence. Demographic information and details of operative technique were correlated with recurrence. Two independent radiologists reviewed all preoperative imaging to identify radiographic markers of IIH, as well as the location and size of the meningoencephalocele. RESULTS From a total of 54 patients there were 5 with recurrences (9.3%), but of the 39 patients in whom a vascularized nasoseptal (n = 31) or turbinate (n = 8) flap was used there were no recurrences (p = 0.0009). The mean time to recurrence was 24.8 months (range 9–38 months). There was a trend to higher BMI in patients whose leak recurred (mean [± SD] 36.6 ± 8.6) compared with those whose leak did not recur (31.8 ± 7.4; p = 0.182). Although the lateral recess of the sphenoid sinus was the most common site of meningoencephalocele, the fovea ethmoidalis was the most common site in recurrent cases (80%; p = 0.013). However, a vascularized flap was used in significantly more patients with sphenoid (78.3%) defects than in patients with fovea ethmoidalis (28.6%) defects (Fisher’s exact test, p = 0.005). Radiographic signs of IIH were equally present in all patients whose leak recurred (75%) compared with patients whose leak did not recur (63.3%); however, an enlarged Meckel cave was present in 100% (2/2) of patients whose leaks recurred compared with 13.3% (4/30) of patients whose leaks did not recur (p = 0.03). The average meningoencephalocele diameter tended to be larger (1.73 ± 1.3 cm) in patients with recurrence compared to those without recurrence (1.2 ± 0.66 cm; p = 0.22). A ventriculoperitoneal shunt was already in place in 3 patients, placed perioperatively in 5, and placed at recurrence in 2, none of whose leaks recurred. CONCLUSIONS Recurrence after endonasal repair of spontaneous CSF leaks from meningoencephaloceles can be dramatically reduced with the use of a vascularized flap. Although failures of endonasal repair tend to occur in patients who have higher BMI, larger brain herniations, and no CSF diversion, the lack of vascularized flap was the single most important risk factor predictive of failure.

OBJECTIVE Surgical management of craniopharyngiomas (CPAs) is challenging. Controversy exists regarding the optimal goals of surgery. The purpose of this study was to compare the long-term outcomes of patients who underwent gross-total resection with the outcomes of those who underwent subtotal resection of their CPA via an endoscopic endonasal approach. METHODS From a prospectively maintained database of all endoscopic endonasal approaches performed at Weill Cornell Medicine, only patients with CPAs with > 3 years of follow-up after surgery were included. The primary endpoint was radiographic progression. Data were collected on baseline demographics, imaging, endocrine function, visual function, and extent of resection. RESULTS A total of 44 patients with a mean follow-up of 5.7 ± 2.6 years were included. Of these patients, 14 (31.8%) had prior surgery. GTR was achieved in 77.3% (34/44) of all patients and 89.5% (34/38) of patients in whom it was the goal of surgery. Preoperative tumor volume < 10 cm3 was highly predictive of GTR (p < 0.001). Radiation therapy was administered within the first 3 months after surgery in 1 (2.9%) of 34 patients with GTR and 7 (70%) of 10 patients with STR (p < 0.001). The 5-year recurrence-free/progression-free survival rate was 75.0% after GTR and 25.0% after STR (45% in subgroup with STR plus radiotherapy; p < 0.001). The time to recurrence after GTR was 30.2 months versus 13 months after STR (5.8 months in subgroup with STR plus radiotherapy; p < 0.001). Patients with GTR had a lower rate of visual deterioration and higher rate of return to work or school compared with those with STR (p = 0.02). Patients with GTR compared to STR had a lower rate of CSF leakage (0.0% vs 30%, p = 0.001) but a higher rate of diabetes insipidus (85.3% vs 50%, p = 0.02). CONCLUSIONS GTR, which is possible to achieve in smaller tumors, resulted in improved tumor control, better visual outcome, and better functional recovery but a higher rate of diabetes insipidus compared with STR, even when the latter was supplemented with postoperative radiation therapy. GTR should be the goal of craniopharyngioma surgery, when achievable with minimal morbidity.

Funder: Wellcome Trust, PurposeSurgical workflow analysis seeks to systematically break down operations into hierarchal components. It facilitates education, training, and understanding of surgical variations. There are known educational demands and variations in surgical practice in endoscopic transsphenoidal approaches to pituitary adenomas. Through an iterative consensus process, we generated a surgical workflow reflective of contemporary surgical practice.MethodsA mixed-methods consensus process composed of a literature review and iterative Delphi surveys was carried out within the Pituitary Society. Each round of the survey was repeated until data saturation and > 90% consensus was reached.ResultsThere was a 100% response rate and no attrition across both Delphi rounds. Eighteen international expert panel members participated. An extensive workflow of 4 phases (nasal, sphenoid, sellar and closure) and 40 steps, with associated technical errors and adverse events, were agreed upon by 100% of panel members across rounds. Both core and case-specific or surgeon-specific variations in operative steps were captured.ConclusionsThrough an international expert panel consensus, a workflow for the performance of endoscopic transsphenoidal pituitary adenoma resection has been generated. This workflow captures a wide range of contemporary operative practice. The agreed "core" steps will serve as a foundation for education, training, assessment and technological development (e.g. models and simulators). The "optional" steps highlight areas of heterogeneity of practice that will benefit from further research (e.g. methods of skull base repair). Further adjustments could be made to increase applicability around the world.

For resected brain metastases (BMs), stereotactic radiosurgery (SRS) is often offered to minimize local recurrence (LR). Although the aim is to deliver SRS within a few weeks of surgery, a variety of socioeconomic, medical, and procedural issues can cause delays. We evaluated the relationship between timing of postoperative SRS and LR.We retrospectively identified a consecutive series of patients with BM managed with resection and SRS or fractionated SRS at our institution from 2012 to 2018. We assessed the correlation of time to SRS and other demographic, disease, and treatment variables with LR, local recurrence-free survival, distant recurrence, distant recurrence-free survival, and overall survival.A total of 133 patients met inclusion criteria. The median age was 64.5 years. Approximately half of patients had a single BM, and median BM size was 2.9 cm. Gross total resection was achieved in 111 patients (83.5%), and more than 90% of patients received fractionated SRS. The median time to SRS was 37.0 days, and the LR rate was 16.4%. Time to SRS was predictive of LR. The median time from surgery to SRS was 34.0 days for patients without LR versus 61.0 days for those with LR (P.01). The LR rate was 2.3% with SRS administered ≤4 weeks postoperatively, compared with 23.6% if SRS was administered4 weeks postoperatively (P.01). Local recurrence-free survival was also improved for patients who underwent SRS at ≤4 weeks (P = .02). Delayed SRS was also predictive of distant recurrence (P = .02) but not overall survival.In this retrospective study, the strongest predictor of LR after postoperative SRS for BM was time to SRS, and a cutoff of 4 weeks was a reliable predictor of recurrence. These findings merit investigation in a prospective, randomized trial.

The COVID-19 pandemic has impacted neurosurgery in unforeseeable ways. Neurosurgical patient care, research, and education have undergone extraordinary modifications as medicine and mankind have adapted to overcome the challenges posed by this pandemic. Some changes will disappear as the situation slowly recovers to a prepandemic status quo. Others will remain: This pandemic has sparked some long-overdue systemic transformations across all levels of medicine, including in neurosurgery, that will be beneficial in the future. In this paper, we present some of the challenges faced across different levels of neurosurgical clinical care, research, and education, the changes that followed, and how some of these modifications have transformed into opportunities for improvement and growth in the future.

OBJECTIVEDespite the rise of studies in the neurosurgical literature suggesting that patients with Medicaid insurance have inferior outcomes, there remains a paucity of data on the impact of insurance on outcomes after endonasal endoscopic transsphenoidal surgery (EETS). Given the increasing importance of complications in quality-based healthcare metrics, the objective of this study was to assess whether Medicaid insurance type influences outcomes in EETS for pituitary adenoma.METHODSThe authors analyzed a prospectively acquired database of EETS for pituitary adenoma from 2005 to 2018 at NewYork-Presbyterian Hospital, Weill Cornell Medicine. All patients with Medicaid insurance were identified. As a control group, the clinical, socioeconomic, and radiographic data of all other patients in the series with non-Medicaid insurance were reviewed. Statistical significance was determined with an alpha < 0.05 using Pearson chi-square and Fisher’s exact tests for categorical variables and the independent-samples t-test for continuous variables.RESULTSOf 584 patients undergoing EETS for pituitary adenoma, 57 (10%) had Medicaid insurance. The maximum tumor diameter was significantly larger for Medicaid patients (26.1 ± 12 vs 23.1 ± 11 mm for controls, p < 0.05). Baseline comorbidities including diabetes mellitus, hypertension, smoking history, and BMI were not significantly different between Medicaid patients and controls. Patients with Medicaid insurance had a significantly higher rate of any complication (14% vs 7% for controls, p < 0.05) and long-term cranial neuropathy (5% vs 1% for controls, p < 0.05). There were no statistically significant differences in endocrine outcome or vision outcome. The mean postoperative length of stay was significantly longer for Medicaid patients compared to the controls (9.4 ± 31 vs 3.6 ± 3 days, p < 0.05). This difference remained significant even when accounting for outliers (5.6 ± 2.5 vs 3.0 ± 2.7 days for controls, p < 0.05). The most common causes of extended length of stay greater than 1 standard deviation for Medicaid patients were management of perioperative complications and disposition challenges. The rate of 30-day readmission was 7% for Medicaid patients and 4.4% for controls, which was not a statistically significant difference.CONCLUSIONSThe authors found that larger tumor diameter, longer postoperative length of stay, higher rate of complications, and long-term cranial neuropathy were significantly associated with Medicaid insurance. There were no statistically significant differences in baseline comorbidities, apoplexy, endocrine outcome, vision outcome, or 30-day readmission.

The Simpson grading scale, developed in 1957 by Donald Simpson, has been considered the gold standard for defining the surgical extent of resection for WHO grade I meningiomas. Since its introduction, the scale and its modifications have generated enormous controversy. The Simpson grade is based on an intraoperative visual assessment of resection, which is subjective and notoriously inaccurate. The majority of studies in which the grading system was used were performed before routine postoperative MRI surveillance was employed, rendering assessments of extent of resection and the definition of recurrence inconsistent. The infiltration and proliferation potential of tumor components such as hyperostotic bone and dural tail vary widely based on tumor location, as does the molecular biology of the tumor, rendering a universal scale for all meningiomas unfeasible. While extent of resection is clearly important at reducing recurrence rates, achieving the highest Simpson grade resection should not always be the goal of surgery.Donald Simpson’s name and his scale deserve to be recognized and preserved in the historical pantheon of pioneering and transformative neurosurgical concepts. Nevertheless, his eponymous scale is no longer relevant in modern meningioma surgery. While his message of maximizing extent of resection and minimizing morbidity is still germane, a single measure using subjective criteria cannot be applied universally to all meningiomas, regardless of location. Meningioma surgery should be performed with the goal of achieving maximal safe resection, ideally guided by molecularly tagged fluorescent labeling and assessed using objective criteria, including postoperative MRI as well as molecularly tagged scans such as [68Ga]-DOTATATE-PET.

Olfactory groove meningiomas (OGMs) are commonly treated with open craniotomy. Endonasal approaches have also been described. To present clinical and radiographic outcomes for the minimally invasive eyebrow incision supraorbital keyhole approach with endoscopic assistance for OGMs. We performed a retrospective single-center cohort study and a systematic literature review. Fifteen patients were identified, all with Grade I meningiomas. Radiographic gross total resection of enhancing tumor was achieved in all patients. Mean frontal lobe fluid-attenuated inversion recovery volume decreased from 11.1 ± 18.3 cm3 preoperatively to 9.9 ± 11.4 cm3 immediately postoperatively, and there was minimal new restricted diffusion (3.2 ± 2.2 cm3; max 7.5 cm3). Median length of stay was 3 days (range 2–8). Vision was improved in 4 (80%) and stable in 1 (20%) of 5 patients with a preoperative deficit. New postoperative anosmia occurred in 3 (23%) of 13 patients with any preoperative olfaction. All patients were satisfied with their cosmetic result at 3 months. After a median follow-up of 32.2 months, there were 2 (13.3%) asymptomatic radiographic recurrences, 1 treated with radiosurgery and the other with endoscopic endonasal approach (EEA). No patients required further craniotomy. Systematic review revealed the present series to be the largest to date reporting disaggregated outcomes for the eyebrow approach to OGM. The eyebrow incision supraorbital keyhole craniotomy with endoscopic assistance is a safe and effective approach to OGM with tumor control rates similar to more invasive open approaches and better than the endonasal approach. Rates of frontal lobe injury, CSF leak and anosmia are comparatively low.

OBJECTIVEPostoperative sellar hematoma is an uncommon complication of endonasal endoscopic transsphenoidal surgery (EETS) for pituitary adenoma that often requires emergency surgical evacuation. Sellar hematomas can cause mass effect and compress parasellar structures, leading to clinically significant symptoms such as visual impairment and severe headache. The objective of this study was to determine the incidence and risk factors associated with reoperation for postoperative hematoma after EETS for pituitary adenoma.METHODSThe authors reviewed a prospectively acquired database of EETS for pituitary adenoma over 13 years at Weill Cornell Medicine, NewYork-Presbyterian Hospital and identified cases that required reoperation for confirmed hematoma. They also reviewed clinical and radiographic data of a consecutive series of patients undergoing EETS for pituitary adenoma who did not have postoperative hematoma, which served as the control group. Demographic data and risk factors were compared between the groups using univariate and multivariate analyses via binary logistic regression.RESULTSAmong a cohort of 583 patients undergoing EETS for pituitary adenoma, 9 patients (1.5%) required operation for sellar hematoma evacuation. All 9 patients with reoperation for sellar hematoma presented with worsening in their vision, and severe headache was present in 67%. New postoperative endocrine dysfunction developed in 78%. Clot evacuation improved vision in 88%. The mean time to hematoma evacuation was 4.5 days. The median length of stay for patients with sellar hematoma was 8 days (range 4–210 days) compared with a median length of stay of 3 days (range 1–32 days) for the control patients (p < 0.005). Significant risk factors in univariate analysis were tumor diameter ≥ 30 mm (p < 0.005), suprasellar extension (p < 0.005), tumor volume (p < 0.005), cavernous sinus invasion (p < 0.05), gonadotroph histology (p < 0.05), antiplatelet use (p < 0.05), and elevated BMI (p < 0.05). On multivariate analysis, tumor diameter ≥ 30 mm (OR 4.555, CI 1.30–28.90; p < 0.05) and suprasellar extension (OR 1.048, CI 1.01–1.10; p < 0.05) were found to be the only independent predictors of sellar hematoma. The incidence of hematoma in tumors ≥ 30 mm was 5% (7/139).CONCLUSIONSPostoperative sellar hematoma requiring reoperation is a rare phenomenon after transsphenoidal surgery, often presenting with visual loss and headache. Clot evacuation results in improvement in vision, but long-term endocrinopathy often ensues. Tumor diameter ≥ 30 mm and suprasellar extent are the most reliable risk factors. Close postoperative scrutiny should be given to patients at high risk.

Purpose Re-irradiation of recurrent glioblastoma (GBM) may delay further recurrence but re-irradiation increases the risk of radionecrosis (RN). Salvage therapy should focus on balancing local control (LC) and toxicity. We report the results of using intraoperative Cesium-131 (Cs-131) brachytherapy for recurrent GBM in a population of patients who also received bevacizumab. Methods and Materials Twenty patients with recurrent GBM underwent maximally safe neurosurgical resection with Cs-131 brachytherapy between 2010 and 2015. Eighty Gy was prescribed to 0.5 cm from the surface of the resection cavity. All patients previously received adjuvant radiotherapy and temozolomide, and received bevacizumab before or after salvage brachytherapy. Seven of 20 (35%) tumors were multiply recurrent and had been previously salvaged with external beam radiotherapy. Patients received MRI scans every 2 months monitored for recurrence, progression, and RN. Results Median tumor diameter was 4.65 cm (range, 1.2–6.3 cm). Median number of seeds pace was 41 (range, 20–74) with total seed activity 96.8U (range, 41.08–201.3U). At a median followup of 19 months, crude LC was 85% and median overall survival was 9 months (range, 5–26 months). There were two postoperative wound infections (10%), three seizures (15%), and 0% incidence of RN. Conclusions Our study demonstrates that while LC and survival are similar to other studies of postoperative external beam radiotherapy, no RN occurred in any of these patients, including 7 multiply re-irradiated patients. Of interest, there were patients with multiple recurrences whose survival extended beyond 20 months. These findings suggest that the use of highly conformal Cs-131 brachytherapy is a promising treatment for patients with recurrent GBM with minimal risk of development of RN.

Background and purpose Glioblastomas (GBMs) that involve the subventricular zone (SVZ) have a poor prognosis, possibly due to recruitment of neural stem cells. The purpose of this study was to evaluate whether SVZ involvement by lower grade gliomas (LGG), WHO grade II and III, similarly predicts poorer outcomes. We further assessed whether tumor genetics and cellularity are associated with SVZ involvement and outcomes. Methods Forty-five consecutive LGG patients with preoperative imaging and next generation sequencing were included in this study. Regional SVZ involvement and whole tumor apparent diffusion coefficient (ADC) values, as a measure of cellularity, were assessed on magnetic resonance imaging. Progression was determined by RANO criteria. Kaplan-Meier curves and Cox regression analyses were used to determine the hazard ratios (HR) for progression and survival. Results Frontal, parietal, temporal, and overall SVZ involvement and ADC values were not associated with progression or survival (P ≥ .05). However, occipital SVZ involvement, seen in two patients, was associated with a higher risk of tumor progression (HR = 6.6, P = .016) and death (HR = 31.5, P = .015), CDKN2A/B mutations (P = .03), and lower ADC histogram values at the 5th (P = .026) and 10th percentiles (P = .046). Isocitrate dehydrogenase, phosphatase and tensin homolog, epidermal growth factor receptor, and cyclin-dependent kinase 4 mutations were also prognostic (P ≤ .05). Conclusions Unlike in GBM, overall SVZ involvement was not found to strongly predict poor prognosis in LGGs. However, occipital SVZ involvement, though uncommon, was prognostic and found to be associated with CDKN2A/B mutations and tumor hypercellularity. Further investigation into these molecular mechanisms underlying occipital SVZ involvement in larger cohorts is warranted.

Endonasal endoscopic transsphenoidal surgery (EETS) for pituitary adenoma has become a mainstay of treatment over the last two decades and it is generally accepted that once this learning curve is achieved, a plateau is reached with little incremental improvement. The objective of this study was to assess the slope of the learning curve over a long period of time for a variety of outcomes measures. We examined outcomes and complications in a consecutive series of 600 EETS for pituitary adenoma grouped into quartiles based on date of surgery. GTR significantly increased across quartiles from 55 to 79% in the last quartile (p

There are few therapeutic options available for the treatment of recurrent meningiomas that have failed treatment with surgery and external-beam radiation therapy (EBRT). As additional EBRT is clinically risky, brachytherapy offers an important alternative for optimizing local control. In skull base meningiomas, the endoscopic endonasal approach (EEA) has demonstrated an excellent extent of resection. However, in the case of recurrent, atypical, or residual meningiomas, the EEA alone may not be adequate to address microscopic, residual, highly proliferative disease. In this situation, local radioactive seed brachytherapy has been shown to improve control, but few reports of this technique exist. A 48-year-old right-handed man presented on multiple occasions with recurrence of an anaplastic skull base meningioma, after multiple prior gross-total resections and multiple rounds of radiotherapy had failed. The authors performed a maximally safe neurosurgical tumor resection via EEA supplemented by the intraoperative implantation of 131Cs low-dose permanent brachytherapy seeds. They describe a technique for permanent implantation of brachytherapy seeds and provide operative video of this technique. The authors submit that utilizing this technique in combination with EEA tumor resection renders a minimally invasive approach to improving local control in a patient with a recurrent anaplastic or atypical meningioma of the skull base.

Skull base reconstruction after extended endoscopic endonasal approaches (EEAs) can be challenging. In addition to the nasoseptal flap, which has been adopted by most centers, autologous fascia lata is also often utilized. Harvesting of fascia lata requires a separate thigh incision, may prolong recovery, and results in a visible scar. In principal, the use of non-autologous materials would be preferable to avoid a second incision and maintain the minimally invasive nature of the approach, assuming the CSF leak rate is not compromised. To assess the efficacy of acellular dermal matrix (ADM) as a non-autologous alternative to autologous fascia lata graft for watertight closure of the cranial base following EEAs. A retrospective chart review of extended EEAs performed before and after the transition from fascia lata to ADM was performed. Cases were frequency matched for approach, pathology, BMI, use of lumbar drainage, and tumor volume. Power analysis was performed to estimate the sample size needed to demonstrate non-inferiority. ADM was used for watertight closure of the cranial base in 19 consecutive extended endoscopic endonasal approaches (16 gasket-seals and 3 buttons) with 1 postoperative CSF leak at the last follow-up (median 5.3, range 1.0–12.6 months). All patients had high-flow intraoperative leaks. The cohort included 8 meningiomas, 8 craniopharyngiomas, 2 chordomas, and 1 pituicytoma ranging in size from 0.2 to 37.2cm3 (median 5.5, IQR 2.8–13.3 cm3). In 19 historical controls who received fascia lata, there were 2 postoperative CSF leaks. Preliminary results suggest that ADM provides a non-inferior non-autologous alternative to fascia lata for watertight gasket-seal and button closures following extended EEAs, potentially reducing or eliminating the need to harvest autologous tissue.

Purpose To compare treatment plans and evaluate dosimetric characteristics of permanent cesium-131 (131Cs) vs. iodine-125 (125I) implants used in brain brachytherapy. Material and methods Twenty-four patients with 131Cs implants from a prospective phase I/II trial were re-planned with 125I implants. In order to evaluate the volume of brain tissue exposed to radiation therapy (RT), the dose volume histogram was generated for both radioisotopes. To evaluate the dosimetric differences of the two radioisotopes we compared homogeneity (HI) and conformity indices (CI), and dose covering 100% (D100), 90% (D90), 80% (D80), and 50% (D50) of the clinical target volume (CTV). Results At the 100%, 90%, 80%, and 50% isodose lines, the 131Cs plans exposed less mean volume of brain tissue than the 125I plans (p < 0.001). The D100, D90, D80, and D50 were smaller for 131Cs (p < 0.001). The HI and CI for 131Cs vs. 125I were 19.71 vs. 29.04 and 1.31 vs. 1.92, respectively (p < 0.001). Conclusions Compared to 125I, 131Cs exposed smaller volumes of brain tissue to equivalent doses of radiation and delivered lower radiation doses to equivalent volumes of the CTV. 131Cs exhibited a higher HI, indicating increased uniformity of doses within the CTV. Lastly, 131Cs presented a CI closer to 1, indicating that the total volume receiving the prescription dose was closer to the desired CTV volume. These results suggest that 131Cs is dosimetrically superior to 125I and may explain the reason for the 0% incidence of radiation necrosis (RN) in our previously published prospective study using 131Cs.

Introduction Rathke's cleft cysts (RCC) are generally treated with transsphenoidal fenestration and cyst drainage. If no cerebrospinal fluid (CSF) leak is created, the fenestration can be left open. If CSF is encountered, a watertight closure must be created to prevent postoperative CSF leak, though sellar closure has theoretically been linked with higher recurrence rate. In this study, we investigate the relationship between sellar closure, rate of postoperative CSF leak, and RCC recurrence. Methods Retrospective review of a prospective database of all endoscopic endonasal RCC fenestrations and cases were divided based on closure. The “open” group included patients who underwent fenestration of the RCC, whereas the “closed” group included patients whose RCC was treated with fat and a rigid buttress ± a nasoseptal flap. The rate of intra- and postoperative CSF leak and radiographic recurrence was determined. Results The closed group had a higher rate of suprasellar extension (odds ratio [OR]: 8.0, p = 0.032) and intraoperative CSF leak (p ≤ 0.001). There were 54.8% intraoperative CSF leaks and no postoperative CSF leaks. Radiologic recurrence rate for the closed group (35.0%) was three times higher than the open group (9.1%; risk ratio [RR] = 3.85, p = 0.203), but not powered to show significance. None of the radiologic recurrences required reoperation. Conclusion Maintaining a patent fenestration between an RCC and the sphenoid sinus is important in reducing the rate of radiographic recurrence. Closure of the fenestration may be required to prevent CSF leak. While closure increases the rate of radiographic recurrence, reoperation for recurrent RCC is still an uncommon event.

In this case report, we present a rare and previously unreported case of spontaneous regression of a histologically consistent clival chordoma. At the time of diagnosis, imaging demonstrated a T2 hyperintense and T1 isointense midline skull base mass, centered in the nasopharynx, with scalloping of the ventral clivus consistent with a chordoma measuring 3.1 × 1.9 × 3.0 cm (8.84 cm3). On pre-operative imaging 2 months later, with no intervening therapy, the mass had regressed by 61.7% to a size of 2.3 × 2.1 × 1.4 cm (3.38 cm3). The patient self-administered several herbal supplements and animal oils which may have contributed to tumor regression. The purpose of this report is to document this rare occurrence and provide a comprehensive description of the case details and list of the various medications, herbs, and supplements used prior to this rare event.

PURPOSEMultiple approaches with [Ga68]-DOTATATE, a somatostatin analog PET radiotracer, have demonstrated clinical utility in evaluation of meningioma but have not been compared directly. Our purpose was to compare diagnostic performance of three approaches to quantitative brain [68Ga]-DOTATATE PET/MRI analysis in patients with suspected meningioma recurrence and to establish the optimal diagnostic threshold for each method.METHODSPatients with suspected meningioma were imaged prospectively with [68Ga]-DOTATATE brain PET/MRI. Lesions were classified as meningiomas and post-treatment change (PTC), based on pathology findings and follow up MRI appearance. Lesions were reclassified using the following methods: absolute SUV threshold (SUV), SUV ratio (SUVR) to superior sagittal sinus (SSS) (SUVRsss), and SUVR to the pituitary gland (SUVRpit). Diagnostic performance of the three methods was compared using contingency tables and McNemar’s test. Previously published pre-determined thresholds were assessed where applicable. The optimal thresholds for each method were identified using Youden’s J statistics.RESULTS166 meningiomas and 41 PTC lesions were identified across 62 patients. SUV, SUVRsss, and SUVRpit of meningioma were significantly higher than those of PTC (PCONCLUSIONWe found that the SUVRsss method may have the most robust combination of sensitivity and specificity in the diagnosis of meningioma in the post-treatment setting, with the optimal threshold of 3.23. Future studies validating our findings in different patient populations are needed to continue optimizing the diagnostic performance of [68Ga]-DOTATATE PET/MRI in meningioma patients. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT04081701. Registered 9 September 2019. https://clinicaltrials.gov/ct2/show/NCT04081701

Background Giant pituitary adenoma represents one of the challenging tumor for neurosurgeons. Many microsurgical approaches in the past were used for its management. Recently and with evolution of the endoscopic equipment and instruments, extended endoscopic transsphenoidal approach become one of the preferable approaches for its surgical excision. Methods We prospectively document the clinical , surgical and follow up data for all patients presented with giant pituitary adenoma to Ain-Shams university hospital and Weill Cornell Medical College, Presbyterian hospital and were surgically treated with extended transsphenoidal approach from 2015 till 2019. Results Our group study formed of 44 patients with mean age 53.03 (range 14.7-82.4) and a male predominance (59%). The main presentation was visual problems in 75% followed by partial hypopituitarism in 31.81% while headache was in 13.64%. Only 4 patients had functioning adenoma (3 prolactinoma and 1 acromegaly). Average tumor volume was 26.95 ± 17.25 cm3, while the mean maximum tumor diameter was 4.73 cm (range 4.0-8.0 cm). Radiographic invasion was found in 97.73% to suprasellar cistern, 61.36% to the cavernous sinus and in 34% to the sphenoid sinus. GTR was achieved in 45.45% with Knosp score is the only significant predictor factor for resection rate (p = 0.04). Visual improvement achieved in 75.76%. 50% (2 patient) of the patients with functioning adenoma were cured. Complications included CSF leak in 3 patients, permanent DI in 4 patients and postoperative hematoma in 2 patients. Recurrence and progression rates without upfront radiation therapy were 5.00 % and 31.81% respectively after mean follow up period 57.90 months. Conclusions Extended endoscopic approaches for achieving maximum resection with minimal morbidity for giant pituitary adenoma are very effective. Lateral tumor extension with cavernous sinus invasion represents the limiting point in achieving gross total resection. Upfront radiation therapy for patients with residual adenoma can be avoided but regular follow up should be warranted.

In partial onset epilepsy, seizures arise focally in the brain and often propagate, causing acute behavior changes, chronic cognitive decline, and increased mortality. Patients frequently become refractory to medical management, leaving neurosurgical resection of the seizure focus as a primary treatment, which can cause neurologic deficits. In the cortex, focal seizures are thought to spread through horizontal connections in layers II/III, suggesting that selectively severing these connections could block seizure propagation while preserving normal columnar circuitry and function. We induced focal neocortical epilepsy in mice and used tightly-focused femtosecond-duration laser pulses to create a sub-surface, opencylinder cut surrounding the seizure focus and severing cortical layers II-IV. We monitored seizure propagation using electrophysiological recordings at the seizure focus and at distant electrodes for 3-8 months. With laser cuts, only 5% of seizures propagated to the distant electrodes, compared to 85% in control animals. Laser cuts also decreased the number of seizures that were initiated, so that the average number of propagated seizures per day decreased from 42 in control mice to 1.5 with laser cuts. Physiologically, these cuts produced a modest decrease in cortical blood flow that recovered within days and, at one month, left a ~20-μm wide scar with increased gliosis and localized inflammatory cell infiltration but minimal collateral damage. When placed over motor cortex, cuts did not cause notable deficits in a skilled reaching task. Femtosecond laser produced sub-surface cuts hold promise as a novel neurosurgical approach for intractable focal cortical epilepsy, as might develop following traumatic brain injury.Once sentence summaryIn a mouse model of focal epilepsy, sub-surface laser-produced cuts encircling the seizure focus attenuate propagation without behavioral impairment.

A 31-year-old male with history of bipolar disorder, suicidal attempts requiring inpatient hospitalization, and seizures on antiepileptic medications presented with increasing seizure frequency. He was neurologically intact yet had multiple facial, axillary, and inguinal flat pigmented macules (cafe au lait spots) and ophthalmologic examination with iris hamartomas (Lisch nodules) consistent with neurofibromatosis type 1. Electroencephalogram was notable for multiple right temporal lobe seizures with anterior temporal interictal epileptiform discharges. Magnetic resonance imaging revealed a T2 hyperintense mass centered in the right amygdala, contiguous with the cystic area. Preoperative intracarotid sodium amobarbital testing showed left-sided language and memory dominance. The patient was operated on for right amygdalohippocampectomy, and initial pathology was consistent with a low-grade neuroepithelial neoplastic process. Further pathologic examination found hypercellular proliferation of predominantly bland, spindled cells with scattered, embedded neurocytic elements with dysplastic appearance, consistent with low-grade glioma. The patient was clinically diagnosed with neurofibromatosis type 1.

Unambiguously identifying an epileptic focus with high spatial resolution is a challenge, especially when no anatomic abnormality can be detected. Neurovascular coupling (NVC)-based brain mapping techniques are often applied in the clinic despite a poor understanding of ictal NVC mechanisms, derived primarily from recordings in anesthetized animals with limited spatial sampling of the ictal core. In this study, we used simultaneous wide-field mesoscopic imaging of GCamp6f and intrinsic optical signals (IOS) to record the neuronal and hemodynamic changes during acute ictal events in awake, behaving mice. Similar signals in isoflurane-anesthetized mice were compared to highlight the unique characteristics of the awake condition. In awake animals, seizures were more focal at the onset but more likely to propagate to the contralateral hemisphere. The HbT signal, derived from an increase in cerebral blood volume (CBV), was more intense in awake mice. As a result, the “epileptic dip” in hemoglobin oxygenation became inconsistent and unreliable as a mapping signal. Our data indicate that CBV-based imaging techniques should be more accurate than blood oxygen level dependent (BOLD)-based imaging techniques for seizure mapping in awake behaving animals.

Even though neurosurgeons exercise these enormous and versatile skills, the COVID-19 pandemic has shaken the fabrics of the global neurosurgical family, jeopardizing human lives, and forcing the entire world to be locked down. We stand on the shoulders of the giants and will not forget their examples and their teachings. We will work to the best of our ability to honor their memory. Professor Harvey Cushing said: "When to take great risks; when to withdraw in the face of unexpected difficulties; whether to force an attempted enucleation of a pathologically favorable tumor to its completion with the prospect of an operative fatality, or to abandon the procedure short of completeness with the certainty that after months or years even greater risks may have to be faced at a subsequent session-all these require surgical judgment which is a matter of long experience." It is up to us, therefore, to keep on the noble path that we have decided to undertake, to accumulate the surgical experience that these icons have shown us, the fruit of sacrifice and obstinacy. Our tribute goes to them; we will always remember their excellent work and their brilliant careers that will continue to enlighten all of us.

Burst suppression is an electroencephalogram pattern of globally symmetric alternating high amplitude activity and isoelectricity that can be induced by general anaesthetics. There is scattered evidence that burst suppression may become spatially non-uniform in the setting of underlying pathology. Here, we induced burst suppression with isoflurane in rodents and then created a neocortical acute seizure focus with injection of 4-aminopyridine (4-AP) in somatosensory cortex. Burst suppression events were recorded before and after creation of the focus using bihemispheric wide-field calcium imaging and multielectrode arrays. We find that the seizure focus elicits a rapid alteration in triggering, initiation, and propagation of burst suppression events. Compared with the non-seizing brain, bursts are triggered from the thalamus, initiate in regions uniquely outside the epileptic focus, elicit marked increases of multiunit activity and propagate towards the seizure focus. These findings support the rapid, widespread impact of focal epilepsy on the extended brain network.

Objective This study was aimed to compare the safety profiles, magnetic resonance imaging (MRI) findings, and sinonasal outcome test (SNOT-22) scores of Adherus dural sealant, a novel tissue glue designed for skull base surgery.Design Present study is a prospective case series.Setting The research work took place at a tertiary-care academic medical center.Participants Consecutive series of 26 patients undergoing endoscopic skull base surgery (ESBS) with Adherus was compared with a control group of 24 patients matched for tumor type and size with DuraSeal as a sealant.Main Outcome Measures Postoperative complication rates, imaging characteristics, and postoperative SNOT-22 scores were measured and compared.Results No postoperative cerebrospinal fluid (CSF) leaks, intracranial hemorrhages, or mucoceles were observed in either cohort. Adherus was more likely to be identifiable on immediate postoperative MRI (50 vs. 20.8%, p = 0.032). In patients in whom a nasoseptal flap was utilized, the flap was opposed to the skull base in all cases regardless of sealant selected. Postoperative SNOT-22 total (17.25 [±10.81] vs. 14.85 [±14.22], p = 0.609) and subdomain scores were similar between the two groups.Conclusions Adherus dural sealant appears to be a safe alternative to Duraseal in ESBS with comparable quality of life outcomes and imaging findings. These preliminary results are promising but should be examined in a larger population with long-term follow-up.

Malignant transformation of intracranial epidermoid cysts is a rare occurrence. We present the second case of such an event occurring in the pineal region and the first case sent for detailed genomic profiling. MRI demonstrated two lesions: a cyst in a quadrigeminal cistern with restricted diffusion on DWI-weighted images and an adjacent, peripherally enhancing tumor with cerebellar infiltration. Both the lesions were completely resected with a small residual of the epidermoid cyst. The final pathology of both lesions was consistent with epidermoid cyst and squamous cell carcinoma (SCC), respectively. The tumor specimen was sent for comprehensive genomic profiling which revealed stable microsatellite status and loss of CDKN2A/B, MTAP (exons 2-8), and PTEN (exons 6-9). Although reports of primary SCC originating from the epidermoid cyst have been previously described, this is the first description of the genomic profile of such a tumor.

Germ cell tumors are rare malignant tumors frequently located in the suprasellar region. Definitive treatment is chemotherapy and radiation. However, in some circumstances, surgery is indicated for biopsy or resection. There are limited reports of the role of the endonasal endoscopic approach (EEA) in the management of this tumor. We present two cases in which EEA was utilized for successful management of germ cell tumor. The most challenging aspect of germ cell tumor management for the treating physician is knowing the proper indications for surgery. In this paper, we highlight two specific instances, namely diagnosis and tumor refractory to chemoradiation. Given the suprasellar location, EEA is an ideal approach.

Intraoperative magnetic resonance imaging (iMRI) is a technology that may improve rates of gross total resection (GTR) for pituitary adenomas. The endoscope is another less expensive technology, which also may maximize resection rates. A direct comparison of these approaches and their additive benefit has never been performed. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standard. PubMed and Embase databases were searched for studies that examined GTR for pituitary adenoma resection with either endoscopic transsphenoidal surgery (eTSS), microscopic transsphenoidal surgery with iMRI (mTSS + iMRI), or endoscopic transsphenoidal surgery with iMRI (eTSS + iMRI). Eighty-five studies that reported GTR rates in 7124 pituitary adenoma patients were identified. For all pituitary adenomas, eTSS had a pooled proportion of GTR of 68.9% (95% CI 64.7–73.0%) which was similar to that of mTSS + iMRI (GTR 68.3%; 95% CI = 59.4–76.5%) and eTSS + iMRI (GTR 70.7%; 95% CI = 56.9–89.6%). For the subgroup of pituitary macroadenomas, pooled proportions for GTR were similar between eTSS and mTSS + iMRI (eTSS: GTR 59.4%; 95% CI = 49.6–68.7% vs mTSS + iMRI: GTR 68.8%; 95% CI = 57.3–79.3%), and higher for eTSS + iMRI (81.1%; 95% CI = 75.5–86.2%). The post-operative CSF leak proportion for eTSS (4.7%; 95% CI = 3.6–5.9%) was similar to that for eTSS + iMRI (3.7%; 95% CI = 1.6–6.5%) and mTSS + iMRI (4.6%; 95% CI = 2.0–8.3%). No direct statistical comparisons could be performed. Final GTR proportions are similar whether the surgeon uses a microscope supplemented with iMRI or endoscope with or without iMRI. The benefit of the two technologies may be complementary for macroadenomas. These findings are important to consider when comparing the efficacy of different technical strategies in the management of pituitary adenomas.

Brain metastases are the most common intracranial malignancies in adults. Surgical resection is the preferred treatment approach when a pathological diagnosis is required, for symptomatic patients who are refractory to steroids, and to decompress lesions causing mass effect. Radiotherapy is administered to improve local control rates after surgical resection. After a brief review of the literature describing the treatment of brain metastases using whole-brain radiotherapy, postoperative stereotactic radiosurgery, preoperative radiosurgery, and brachytherapy, we compare patient-related, technical, practical, and radiobiological considerations of each technique. Finally, we focus our discussion on intraoperative brachytherapy, with an emphasis on the technical aspects, benefits, efficacy, and outcomes of studies utilizing permanent Cs-131 implants.

Background With recent advances in endoscopic skull base surgery, larger and more complex skull base defects are encountered and many possible reconstructive methods and materials are available. The purpose of this review is to summarize the possible causes of skull base defects, to describe the challenges associated with skull base reconstruction, and to detail the techniques and materials that may be used. Methods Literature review. Results Although skull base defects may be caused by traumatic or nontraumatic causes, this review focuses on the endoscopic reconstruction of defects. Many materials are available for endoscopic reconstruction and several techniques have been described for repair of skull base defects. With these advances, the outcomes of endoscopic skull base reconstruction have improved greatly over the past 20 years. Conclusions Given the complexity of skull base defects and the multiple materials and techniques available for endoscopic reconstruction, a thorough understanding of the challenges associated with skull base repair is crucial for the endoscopic skull base surgeon.

Background Endoscopic skull base surgery is a relatively new approach in the neurosurgical armamentarium and its usefulness is still being explored. As the field has evolved, so too have the results. For this reason, it is important to re-examine the outcomes of surgery for a variety of diseases individually over time to determine the appropriate indications for these approaches. Methods We performed a systematic review of recent literature (since 2012) of all studies using the endoscopic endonasal approach (EEA) for craniopharyngioma, olfactory groove, planum sphenoidale, tuberculum sellae meningioma, esthesioneuroblastoma, chordoma, and chondrosarcoma and discuss outcomes compared with a transcranial approach (TCA). These results are also compared with a series of reviews of the literature that were performed before 2012 to see how results have evolved over time. Results For chordomas, craniopharyngioma and planum sphenoidale/tuberculum sellae meningiomas, EEA has shown superior outcomes to TCA for well-selected cases. Olfactory groove meningiomas still have a better outcome when performed using TCA. Esthesioneuroblastoma requires consideration of tumor stage and extent to select the appropriate approach, although with time, more advanced tumors have become approachable with EEA. Chondrosarcoma is a rare lesion that may be resectable by EEA when anatomy is favorable, although its rarity makes comparison difficult. Conclusions Advances in EEA make it a useful tool that is at times superior to TCA for specific diseases based on recently published literature reporting rates of resection and complications. Ongoing re-evaluation of outcomes is essential to providing the best information to surgeons choosing an approach in each patient.

OBJECTIVEEndoscopic skull base surgery (ESBS) is a relatively recent addition to the neurosurgical armamentarium. As with many new approaches, there has been significant controversy regarding its value compared with more traditional approaches to ventral skull base pathology. Although early enthusiasm for new approaches that appear less invasive is usually high, these new techniques require rigorous study to ensure that widespread implementation is in the best interest of patients.METHODSThe authors compared surgical results for ESBS with transcranial surgery (TCS) for several different pathologies over two different time periods (prior to 2012 and 2012–2017) to see how results have evolved over time. Pathologies examined were craniopharyngioma, anterior skull base meningioma, esthesioneuroblastoma, chordoma, and chondrosarcoma.RESULTSESBS offers clear advantages over TCS for most craniopharyngiomas and chordomas. For well-selected cases of planum sphenoidale and tuberculum sellae meningiomas, ESBS has similar rates of resection with higher rates of visual improvement, and more recent results with lower CSF leaks make the complication rates similar between the two approaches. TCS offers a higher rate of resection with fewer complications for olfactory groove meningiomas. ESBS is preferred for lower-grade esthesioneuroblastomas, but higher-grade tumors often still require a craniofacial approach. There are few data on chondrosarcomas, but early results show that ESBS appears to offer clear advantages for minimizing morbidity with similar rates of resection, as long as surgeons are familiar with more complex inferolateral approaches.CONCLUSIONSESBS is maturing into a well-established approach that is clearly in the patients’ best interest when applied by experienced surgeons for appropriate pathology. Ongoing critical reevaluation of outcomes is essential for ensuring optimal results.

Objectives The utilization of the nasoseptal flap (NSF) in endoscopic anterior skull base surgery (EASB) has resulted in reduced rates of postoperative cerebrospinal fluid leak (CSF). The long-term impact on sinonasal function after surgery remains incompletely defined. Methods A consecutive series of patients undergoing EASB with NSF and with at least 3 years follow-up was prospectively evaluated. Patient demographics, pre- and postoperative Sino-nasal Outcome Test-22 (SNOT-22) scores, Lund-Mackay scores (LMS), CSF leak, and sinonasal complications were analyzed. Results A total of 46 patients undergoing EASB with NSF met inclusion criteria. The mean follow-up was 67.4 months (range 39-90, standard deviation [SD] 14.2 months). No statistically significant differences were noted between the mean overall pre- (16) and postoperative SNOT-22 scores (18). SNOT-22 scores improved in 27 patients (58.7%), deteriorated in 17 patients (37.0%) and stayed the same in two patients (4.3%). Deterioration in SNOT-22 scores was greater in younger (mean change + 7.2 [SD17.4] vs. older patients -3.4 [SD 7.5], P = 0.010). A statistically significant increase in LMS was noted (mean preoperative LMS0.9 vs. mean postoperative LMS 2.2, P = 0.001). The LMS decreased in nine patients (19.6%), increased in 22 patients (47.8%), and remained the same in 15 patients (32.6%). One patient (2.2%) developed a postoperative CSF leak following resection of metastatic skull base lesion and was successfully treated with placement of a lumbar drain, Foley catheter balloon, and strict bed rest. One patient (2.2%) developed a postoperative mucocele requiring decompression 3 years after initial surgery. Conclusion Whereas long-term sinonasal quality of life is overall improved in the majority of patients following NSF use for EASB, younger patients show higher incidence of deterioration. Increased sinus opacification on imaging is generally noted and may require continued follow-up and management. The incidence of reoperation for symptomatic mucocele formation is low. Level of evidence 4 Laryngoscope, 129:1035-1040, 2019.

The operative management of craniopharyngiomas has evolved over the last two decades. Traditional transcranial microsurgical approaches were the only option until the advent of the endoscopic endonasal approach. It has given surgeons the ability to tackle a challenging entity from a new perspective with comparable if not superior results. In this review we outline the advancements in endoscopic endonasal approach for craniopharyngiomas, address controversies and review the current literature.

Olfactory groove meningiomas (OGMs) are commonly treated with open craniotomy. Endonasal approaches have also been described. To present clinical and radiographic outcomes for the minimally invasive eyebrow incision supraorbital keyhole approach with endoscopic assistance for OGMs. We performed a retrospective single-center cohort study and a systematic literature review. Fifteen patients were identified, all with Grade I meningiomas. Radiographic gross total resection of enhancing tumor was achieved in all patients. Mean frontal lobe fluid-attenuated inversion recovery volume decreased from 11.1 ± 18.3 cm3 preoperatively to 9.9 ± 11.4 cm3 immediately postoperatively, and there was minimal new restricted diffusion (3.2 ± 2.2 cm3; max 7.5 cm3). Median length of stay was 3 days (range 2–8). Vision was improved in 4 (80%) and stable in 1 (20%) of 5 patients with a preoperative deficit. New postoperative anosmia occurred in 3 (23%) of 13 patients with any preoperative olfaction. All patients were satisfied with their cosmetic result at 3 months. After a median follow-up of 32.2 months, there were 2 (13.3%) asymptomatic radiographic recurrences, 1 treated with radiosurgery and the other with endoscopic endonasal approach (EEA). No patients required further craniotomy. Systematic review revealed the present series to be the largest to date reporting disaggregated outcomes for the eyebrow approach to OGM. The eyebrow incision supraorbital keyhole craniotomy with endoscopic assistance is a safe and effective approach to OGM with tumor control rates similar to more invasive open approaches and better than the endonasal approach. Rates of frontal lobe injury, CSF leak and anosmia are comparatively low.

Background: The COVID-19 pandemic has revealed deficiencies in the adequacy of personal protective equipment (PPE) forhealth care workers. Endoscopic endonasal skull base surgery (ESBS) is thought to be among the highest risk aerosol-generating procedures (AGPs) for surgeons and operating room personnel. Objective: To validate the efficacy and clinical feasibility of a novel surgical device. Methods: A low-cost, modifiable, and easily producible negative pressure, face-mounted antechamber was developedutilizing 3D printing and silicone molding. Efficacy was evaluated using an optical particle sizer (OPS) to quantify aerosolsgenerated during both cadaver and intraoperative human use with high-speed drilling. Results: Particle counts in the cadaver showed that drilling led to a 2.49-fold increase in particles ≤5 μm ( p = 0.001), andthat the chamber was effective at reducing particles to levels not significantly different than baseline. In humans, drillingled to a 37-fold increase in in particles ≤5 μm ( p < 0.001), and the chamber was effective at reducing particles to a level notsignificantly different than baseline. Use of the antechamber in 6 complex cases did not interfere with the ability to performsurgery. Patients did not report any facial discomfort after surgery related to antechamber use. Conclusions: The use of a negative pressure facial antechamber can effectively reduce aerosolization from endoscopicdrilling without disturbing the flow of the operation. The antechamber, in conjunction with appropriate PPE, will be usefulduring the COVID-19 pandemic, as well as during flu season and any future viral outbreaks.

BACKGROUNDEsthesioneuroblastoma (ENB), also known as olfactory neuroblastoma, is a rare sinonasal neuroectodermal malignancy with a slow onset of symptoms, favorable 5-year survival, and a propensity for delayed locoregional recurrence. Current treatment options include resection, adjuvant radiotherapy, and/or chemotherapy; however, because of its rarity and location, determining the optimal treatment for ENB has been challenging.OBSERVATIONSENBs strongly express somatostatin receptors (SSTRs), particularly SSTR2, providing a molecular target for imaging and therapy.LESSONsThe authors present a case series of ENBs imaged with [68Ga]-DOTATATE PET/MRI and PET/CT and discuss the emerging role of [68Ga]-DOTATATE PET for ENB diagnosis, staging, and treatment response monitoring.

Neurosurgical use of an orbital corridor has greatly advanced with the use of the endoscope. Tools and techniques used with the recent explosion of endonasal approaches is a large reason for this progression. The transorbital approach has proven effective in exposure of anterior and middle cranial fossa lesions with the possibility of exposing posterior fossa lesions through the petrous apex. Transorbital approaches have been used successfully in the treatment of cerebrospinal fluid leaks, orbital fractures, frontal sinus fractures, meningoceles, and encephaloceles. In addition, more groups are using these approaches for resection of mass lesions. Transorbital approaches, when combined with other skull base approaches, provide a minimally invasive but full access to lesions without a large cranial approach. Transorbital access remains a large area of interest and growth for skull base surgeons.

Background The role of postoperative upfront radiotherapy (RT) in the management of gross totally resected atypical meningiomas remains unclear. This single-center retrospective review of newly diagnosed histologically confirmed cases of World Health Organization (WHO) Grade II atypical meningioma at Weill Cornell Medicine from 2004 to 2020 aims to compare overall survival (OS) and progression-free survival (PFS) of postoperative upfront RT versus observation, stratified by resection status (gross total resection [GTR] vs subtotal resection [STR]). Methods Ninety cases of atypical meningioma were reviewed (56% women; median age 61 years; median follow-up 41 months). Results In patients with GTR, hazard ratio (HR) of PFS was 0.09 for postoperative upfront RT versus observation alone (95% confidence interval [CI] 0.01–0.68; P = .02), though HR for OS was not significant (HR 0.46; 95% CI 0.05–4.45; P = .5). With RT, PFS was 100% at 12 and 36 months (compared to 84% and 63%, respectively, with observation); OS at 36 months (OS36) was 100% (compared to 94% with observation). In patients with STR, though PFS at 36 months was higher for RT arm versus observation (84% vs 74%), OS36 was 100% in both arms. HR was not significant (HR 0.76; 95% CI 0.16–3.5; P = .73). Conclusions This retrospective study suggests postoperative upfront RT following GTR of atypical meningioma is associated with improved PFS compared to observation. Further studies are required to draw conclusions about OS.

OBJECTIVE Visual deterioration after endoscopic endonasal transsphenoidal surgery (EETS) for sellar and parasellar masses is a rare but serious complication caused by either compressive or ischemic mechanisms. Timely diagnosis and intervention may restore vision if instituted appropriately. The associated risk factors and their relation to the success of intervention are not well understood. METHODS The authors examined a series of 1200 consecutive EETS cases performed by the senior author at Weill Cornell/NewYork-Presbyterian Hospital from 2010 to 2020. Cases with postoperative visual deterioration were identified. Pre- and postoperative clinical data, mechanism of visual decline, latency to intervention, and long-term visual outcome were retrospectively collected and analyzed with appropriate statistical methods. RESULTS Twenty-one patients (1.75%) complained of early postoperative visual deterioration. The most common pathology associated with postoperative visual loss was craniopharyngioma (7.69%), followed by meningioma (5.43%) and then pituitary adenoma (1.94%). Timely intervention restored vision in 81% of patients for a 0.33% rate of permanent visual deterioration. Average time to visual deterioration was 28.8 hours, and over 70% of patients experienced vision loss within the first 13 hours. Compressive etiology (n = 11), consisting of either hematoma (n = 8) or graft displacement (n = 3), occurred 7.3 hours and 70.3 hours after surgery, respectively, and was more common in adenomas. Acute postoperative visual deterioration was more common in firm closures (4.78%) compared with soft closures (1.03%; p = 0.0006). Ischemic etiology (n = 10) occurred 10.3 hours after surgery and was more common with craniopharyngiomas and meningiomas (p = 0.08). Sixteen patients (76.2%) underwent early reoperation to explore and decompress the optic apparatus. Vision was restored to baseline after reoperation in all 11 compressive cases, whereas 6/10 ischemic cases improved with supplemental oxygen and hypervolemic hypertensive therapy (p = 0.02). Fluid expansion from 8 to 16 hours (p = 0.034) and systolic blood pressure elevation from 32 to 48 hours (p = 0.05) after surgery were significantly higher in those ischemic patients who recovered some vision compared with those with persistent visual deficits. CONCLUSIONS Visual deterioration after EETS is a rare event but can be effectively treated if acted upon appropriately and in a timely fashion. Compressive etiology is reversible with early reoperation. Ischemic etiology can be successfully treated in roughly half of cases with supplemental oxygen and hypertensive hypervolemic therapy but may result in permanent visual deterioration if not instituted appropriately or if delayed with unnecessary exploratory surgery.

Background With advances in imaging techniques, encephaloceles, meningoceles, and meningoencephaloceles are occasionally discovered incidentally. These can be located in anterior cranial fossa (ACF), mostly protruding into sphenoid and ethmoid sinuses, or middle cranial fossa (MCF), protruding into the temporal bone. We reviewed a large series of cranial computed tomography and magnetic resonance imaging scans to identify the prevalence of asymptomatic encephaloceles, meningoceles, and meningoencephaloceles and describe their outcome. Methods We retrospectively reviewed a database of all magnetic resonance imaging and computed tomography scans done at Weill Cornell Medicine for any reason between 2003 and 2018. Encephaloceles, meningoceles, or meningoencephaloceles were confirmed on 72 scans. Of these, chart reviews were performed to identify incidentally discovered cases with symptoms other than cerebrospinal fluid leak, and chart reviews and phone calls were conducted to determine patient demographics, treatment, and outcome. Results There were 18 incidental cases for a prevalence of 0.0074%, of which 6 were located in ACF, and 12 were located in MCF. The mean age for ACF cases was 39 ± 15.9 years and for MCF cases was 49.5 ± 19.8 years. There were no leaks in any cases after the encephaloceles were discovered. Eleven of 12 (91.6%) MCF cases were treated conservatively, while 3 of 6 (50%; P = 0.083) ACF cases were treated surgically. Conclusions This study showed that encephaloceles, meningoceles, and meningoencephaloceles without cerebrospinal fluid leak or meningitis in MCF were more often conservatively managed with observation only, whereas these entities in ACF were often repaired prophylactically. Incidentally discovered encephaloceles have a relatively benign natural history and do not precipitously leak.

OBJECTIVE To identify and characterize patterns of fluctuating contrast enhancement on magnetic resonance imaging (MRI) in patients with oligodendrogliomas. INTRODUCTION Gliomas, particularly oligodendrogliomas, can exhibit fluctuating enhancement (FE) on MRI that can make it difficult to differentiate between treatment effect and active tumor. METHODS We are conducting a single-center retrospective review of clinical and radiographic data for patients with oligodendrogliomas treated at Weill Cornell Medicine (WCM) from 2/2000-5/2018. We have identified patients with FE on MRI and tracked lesions > 5mm in at least one dimension to the resolution of the lesion or last available MRI. We have recorded time from initial diagnosis to development of FE, time from radiation to development of FE, and time from development to resolution of FE as well as molecular characteristics of each tumor. RESULTS A total of 122 patients with oligodendrogliomas were identified. Thus far, fluctuating enhancement has been identified in 11 patients (5 men, 6 women) with 38 total fluctuating lesions. Isocitrate dehydrogenase-1 (IDH-1) mutation was present in 5 tumors, and 1p/19q co-deletion was present in 6. Mean time from initial diagnosis to development of FE was 44.6 months. In patients who developed FE after radiation, mean time from radiation to development of FE was 35.0 months. Twenty-seven lesions resolved, and mean time from onset to resolution of FE was 5.6 months, while mean time from start of radiation to resolution of FE was 41.0 months. Additionally, we will perform perfusion analysis on lesions > 5mm and identify patients who underwent surgical biopsy of FE with pathologic diagnosis. CONCLUSIONS FE has been identified in 11 patients thus far. We are expanding our analysis to identify a larger cohort of patients with FE. Characterizing patterns of FE may aid clinicians in differentiating FE due to treatment effect from active tumor.

OBJECTIVE The authors developed a negative-pressure, patient face-mounted antechamber and tested its efficacy as a tool for sequestering aerated particles and improving the safety of endonasal surgical procedures. METHODS Antechamber prototyping was performed with 3D printing and silicone-elastomer molding. The lowest vacuum settings needed to meet specifications for class I biosafety cabinets (flow rate ≥ 0.38 m/sec) were determined using an anemometer. A cross-validation approach with two different techniques, optical particle sizing and high-speed videography/shadowgraphy, was used to identify the minimum pressures required to sequester aerosolized materials. At the minimum vacuum settings identified, physical parameters were quantified, including flow rate, antechamber pressure, and time to clearance. RESULTS The minimum tube pressures needed to meet specifications for class I biosafety cabinets were −1.0 and −14.5 mm Hg for the surgical chambers with (“closed face”) and without (“open face”) the silicone diaphragm covering the operative port, respectively. Optical particle sizing did not detect aerosol generation from surgical drilling at these vacuum settings; however, videography estimated higher thresholds required to contain aerosols, at −6 and −35 mm Hg. Simulation of surgical movement disrupted aerosol containment visualized by shadowgraphy in the open-faced but not the closed-faced version of the mask; however, the closed-face version of the mask required increased negative pressure (−15 mm Hg) to contain aerosols during surgical simulation. CONCLUSIONS Portable, negative-pressure surgical compartments can contain aerosols from surgical drilling with pressures attainable by standard hospital and clinic vacuums. Future studies are needed to carefully consider the reliability of different techniques for detecting aerosols.

OBJECTIVE Publications on adjuvant stereotactic radiosurgery (SRS) are largely limited to patients completing SRS within a specified time frame. The authors assessed real-world local recurrence (LR) for all brain metastasis (BM) patients referred for SRS and identified predictors of SRS timing. METHODS The authors retrospectively identified BM patients undergoing resection and referred for SRS between 2012 and 2018. Patients were categorized by time to SRS, as follows: 1) ≤ 4 weeks, 2) > 4–8 weeks, 3) > 8 weeks, and 4) never completed. The relationships between timing of SRS and LR, LR-free survival (LRFS), and survival were investigated, as well as predictors of and reasons for specific SRS timing. RESULTS In a cohort of 159 patients, the median age at resection was 64.0 years, 56.5% of patients were female, and 57.2% were in recursive partitioning analysis (RPA) class II. The median preoperative tumor diameter was 2.9 cm, and gross-total resection was achieved in 83.0% of patients. All patients were referred for SRS, but 20 (12.6%) did not receive it. The LR rate was 22.6%, and the time to SRS was correlated with the LR rate: 2.3% for patients receiving SRS at ≤ 4 weeks postoperatively, 14.5% for SRS at > 4–8 weeks (p = 0.03), and 48.5% for SRS at > 8 weeks (p < 0.001). No LR difference was seen between patients whose SRS was delayed by > 8 weeks and those who never completed SRS (48.5% vs 50.0%; p = 0.91). A similar relationship emerged between time to SRS and LRFS (p < 0.01). Non–small cell lung cancer pathology (p = 0.04), earlier year of treatment (p < 0.01), and interval from brain MRI to SRS (p < 0.01) were associated with longer intervals to SRS. The rates of receipt of systemic therapy also differed significantly between patients by category of time to SRS (p = 0.02). The most common reasons for intervals of > 4–8 weeks were logistic, whereas longer delays or no SRS were caused by management of systemic disease or comorbidities. CONCLUSIONS Available data on LR rates after adjuvant SRS are often obtained from carefully preselected patients receiving timely treatment, whereas significantly less information is available on the efficacy of adjuvant SRS in patients treated under “real-world” conditions. Management of these patients may merit reconsideration, particularly when SRS is not delivered within ≤ 4 weeks of resection. The results of this study indicate that a substantial number of patients referred for SRS either never receive it or are treated > 8 weeks postoperatively, at which time the SRS-treated patients have an LR risk equivalent to that of patients who never received SRS. Increased attention to the reasons for prolonged intervals from surgery to SRS and strategies for reducing them is needed to optimize treatment. For patients likely to experience delays, other radiotherapy techniques may be considered.

OBJECTIVEIncomplete resection of skull base pathology may result in local tumor recurrence. This study investigates the utility of 5-aminolevulinic acid (5-ALA) fluorescence during endoscopic endonasal approaches (EEAs) to increase visibility of pathologic tissue.METHODSThis retrospective multicenter series comprises patients with planned resection of an anterior skull base lesion who received preoperative 5-ALA at two tertiary care centers. Diagnostic use of a blue light endoscope was performed during EEA for all cases. Demographic and tumor characteristics as well as fluorescence status, quality, and homogeneity were assessed for each skull base pathology.RESULTSTwenty-eight skull base pathologies underwent blue-light EEA with preoperative 5-ALA, including 15 pituitary adenomas (54%), 4 meningiomas (14%), 3 craniopharyngiomas (11%), 2 Rathke’s cleft cysts (7%), as well as plasmacytoma, esthesioneuroblastoma, and sinonasal squamous cell carcinoma. Of these, 6 (21%) of 28 showed invasive growth into surrounding structures such as dura, bone, or compartments of the cavernous sinus. Tumor fluorescence was detected in 2 cases (7%), with strong fluorescence in 1 tuberculum sellae meningioma and vague fluorescence in 1 pituicytoma. In all other cases fluorescence was absent. Faint fluorescence of the normal pituitary gland was seen in 1 (7%) of 15 cases. A comparison between the particular tumor entities as well as a correlation between invasiveness, WHO grade, Ki-67, and positive fluorescence did not show any significant association.CONCLUSIONSWith the possible exception of meningiomas, 5-ALA fluorescence has limited utility in the majority of endonasal skull base surgeries, although other pathology may be worth investigating.

Craniopharyngioma (CP) is a rare embryonic tumor of the sellar and parasellar region with benign histology (World Health Organization grade I) thought to arise from embryonic remnants of Rathke’s pouch. Despite its high survival rates, this tumor can lead to severe morbidity secondary to destruction of adjacent structures. Hypothalamus (HT) is a brain region that has a central role in regulating body weight through a complex mechanism involving central and peripheral signaling pathways. Destruction of its distinctive nuclei induces hyperphagia, hyperinsulinemia and weight gain. Seventy-five patients with CP who underwent first surgical resection in a single center by the same neurosurgeon between February 2005 and March 2019 were screened; those who have had prior radiation, were aged below 18 years, or did not have follow up body mass index (BMI) after surgery were excluded. Ultimately, this study included 45 patients with a mean age 50.5 years, 73.3% women. Pre and post-operative MRI were independently reviewed by three neuroradiologists to determine involvement of the hypothalamic regions: anterior, anterior and posterior, or no hypothalamic involvement. Body mass index were recorded pre operatively and subsequently after TSS up to 24 months post operation. Association between hypothalamic region involvement and BMI as well as endocrine function were examined. Posterior hypothalamic involvement seen in pre operative MRI (N=28) was significantly associated with higher BMI at 3-6 month, 7-12 month, and 13-24 month follow up (p < 0.05) in comparison to involvement of anterior hypothalamic alone or no hypothalamic involvement. Similarly, posterior hypothalamic involvement in the pre and post-operative MRI was significantly associated with development of diabetes insipidus (DI) (p < 0.05) compared to anterior or no hypothalamic involvement. There was no association between pre-operative BMI and hypothalamic involvement. Although the weight gain was accelerated after surgery, there was no association between post operative MRI and ensuing BMI, suggesting that the damage of the hypothalamic nuclei was done by the CP rather than surgical procedure. Conclusion: Assessment of hypothalamic involvement by anterior and posterior regions on pre operative MRI can be helpful in predicting development of obesity in patients with CP.