Innovative growth and development of a neurological surgery residency cadaveric spine-simulation training program: a single-institution experience.

OBJECTIVE: Cadaveric and dry 3D model-based simulation training is a valuable educational tool for neurosurgical residents. Such simulation training is an opportunity for residents to hone technical skills and decision-making and enhance their neuroanatomy knowledge. The authors describe the growth and development of the Oregon Health & Science University Department of Neurological Surgery resident-focused, hands-on, spine-simulation surgery courses and provide details of course evaluations, layout, and setup. METHODS: A four-part spine surgical simulation series, including two human cadaveric and two dry 3D model-based courses, was created to provide resident spine procedure training. Residents participated in the spine simulation series (2017-2021) and completed annual course curriculum and anonymous post-course evaluations. Evaluations included both Likert scale items and free-text responses. Responses to Likert scale items were analyzed in Python. Free-text responses were quantified using the Valence Aware Dictionary for Sentiment Reasoner. Descriptive statistics were calculated and plotted using Python's seaborn and matplotlib library modules. RESULTS: The analysis included 129 spine (occipitocervical, thoracolumbar, and spine model fusion I and II) simulation course evaluations. Likert responses demonstrated high average responses for evaluation questions (4.67 ± 0.90 and above). The average compound sentiment value was 0.58 ± 0.28. CONCLUSIONS: This is the first time Likert responses and sentiment analysis have been used to demonstrate how neurosurgical residents positively value a hands-on spine simulation training. Simulation is an essential component of neurosurgical resident education training. The authors encourage other neurosurgical education programs to develop and leverage spine simulation as a teaching tool.

Obesity and meningioma: a US population-based study paired with analysis of a multi-institutional cohort.

OBJECTIVE: Whether obesity is associated with meningioma and the impact of obesity by gender has been debated. The primary objective of this study was to investigate differences in BMI between male and female patients undergoing craniotomy for meningioma and compare those with patients undergoing craniotomy for other intracranial tumors. The secondary objective was to compare meningioma location and progression-free survival (PFS) between obese and nonobese patients in a multi-institutional cohort. METHODS: National data were obtained from the National Surgical Quality Improvement Program (NSQIP) database. Male and female patients were analyzed separately. Patients undergoing craniotomies for meningioma were compared with patients of the same sex undergoing craniotomies for other intracranial tumors. Institutional data from two academic centers were collected for all male and an equivalent number of female meningioma patients undergoing meningioma resection. Multivariate regression controlling for age was used to determine differences in meningioma location. Kaplan-Meier curves and log-rank tests were computed to investigate differences in PFS. RESULTS: From NSQIP, 4163 male meningioma patients were compared with 24,266 controls, and 9372 female meningioma patients were compared with 21,538 controls. Male and female patients undergoing meningioma resection were more likely to be overweight or obese compared with patients undergoing craniotomy for other tumors, with the odds ratio increasing with increasing weight class (all p < 0.0001). In the multi-institutional cohort, meningiomas were more common along the skull base in male patients (p = 0.0123), but not in female patients (p = 0.1246). There was no difference in PFS between obese and nonobese male (p = 0.4104) or female (p = 0.5504) patients. Obesity was associated with increased risk of pulmonary embolism in both male and female patients undergoing meningioma resection (p = 0.0043). CONCLUSIONS: Male and female patients undergoing meningioma resection are more likely to be obese than patients undergoing craniotomy for other intracranial tumors. Obese males are more likely to have meningiomas in the skull base compared with other locations, but this association was not found in females. There was no significant difference in PFS among obese patients. The mechanism by which obesity increases meningioma incidence remains to be determined.

Deciphering spatially distinct immune microenvironments in glioblastoma using ferumoxytol and gadolinium-enhanced and FLAIR hyperintense MRI phenotypes.

Background: MRI with gadolinium (Gd)-contrast agents is used to assess glioblastoma treatment response but does not specifically reveal heterogeneous biology or immune microenvironmental composition. Ferumoxytol (Fe) contrast is an iron nanoparticle that localizes glioblastoma macrophages and microglia. Therefore, we hypothesized that the use of Fe contrast improves upon standard Gd-based T1-weighted and T2/FLAIR analysis by specifically delineating immune processes. Methods: In this, HIPAA-compliant institutional review board-approved prospective study, stereotactic biopsy samples were acquired from patients with treatment-naïve and recurrent glioblastoma based on MR imaging phenotypes; Gd and Fe T1 enhancement (Gd+, Fe+) or not (Gd-, Fe-), as well as T2-Flair hyperintensity (FLAIR+, FLAIR-). Analysis of genetic expression was performed with RNA microarrays. Imaging and genomic expression patterns were compared using false discovery rate statistics. Results: MR imaging phenotypes defined a variety of immune pathways and Hallmark gene sets. Gene set enrichment analysis demonstrated that Gd+, Fe+, and FLAIR+ features were individually correlated with the same 7 immune process gene sets. Fe+ tissue showed the greatest degree of immune Hallmark gene sets compared to Gd+ or Flair+ tissues and had statistically elevated M2 polarized macrophages, among others. Importantly, the FLAIR+ Gd+ and Fe- imaging phenotypes did not demonstrate expression of immune Hallmark gene sets. Conclusions: Our study demonstrates the potential of Fe and Gd-enhanced MRI phenotypes to reveal spatially distinct immune processes within glioblastoma. Fe improves upon the standard of care Gd enhancement by specifically localizing glioblastoma-associated inflammatory processes, providing valuable insights into tumor biology.

Low body mass index patients have worse outcomes after mechanical thrombectomy.

BACKGROUND: There is evidence that frailty is an independent predictor of worse outcomes after stroke. Similarly, although obesity is associated with a higher risk for stroke, there are multiple reports describing improved mortality and functional outcomes in higher body mass index (BMI) patients in a phenomenon known as the obesity paradox. We investigated the effect of low BMI on outcomes after mechanical thrombectomy (MT). METHODS: We conducted a retrospective analysis of 231 stroke patients who underwent MT at an academic medical center between 2020-2022. The patients' BMI data were collected from admission records and coded based on the Centers for Disease Control and Prevention (CDC) obesity guidelines. Recursive partitioning analysis (RPA) in R software was employed to automatically detect a BMI threshold associated with a significant survival benefit. Frailty was quantified using the Modified Frailty Index 5 and 11. RESULTS: In our dataset, by CDC classification, 2.6% of patients were underweight, 27.3% were normal BMI, 30.7% were overweight, 19.9% were class I obese, 9.5% were class II obese, and 10% were class III obese. There were no significant differences between these groups. RPA identified a clinically significant BMI threshold of 23.62 kg/m2. Independent of frailty, patients with a BMI ≤23.62 kg/m2 had significantly worse overall survival (P<0.001) and 90-day modified Rankin Scale (P=0.027) than patients above the threshold. CONCLUSIONS: Underweight patients had worse survival and functional outcomes after MT. Further research should focus on the pathophysiology underlying poor prognosis in underweight MT patients, and whether optimizing nutritional status confers any neuroprotective benefit.

Response to Preoperative Dexamethasone Predicts Postoperative Neurological Improvement of Focal Neurological Deficits in Patients With Brain Metastases.

BACKGROUND: Steroids are used ubiquitously in the preoperative management of patients with brain tumor. The rate of improvement in focal deficits with steroids and the prognostic value of such a response are not known. OBJECTIVE: To determine the rate at which focal neurological deficits respond to preoperative corticosteroids in patients with brain metastases and whether such an improvement could predict long-term recovery of neurological function after surgery. METHODS: Patients with brain metastases and related deficits in language, visual field, or motor domains who received corticosteroids before surgery were identified. Characteristics between steroid responders and nonresponders were compared. RESULTS: Ninety six patients demonstrated a visual field (13 patients), language (19), or motor (64) deficit and received dexamethasone in the week before surgery (average cumulative dose 43 mg; average duration 2.7 days). 38.5% of patients' deficits improved with steroids before surgery, while 82.3% of patients improved by follow-up. Motor deficits were more likely to improve both preoperatively ( P = .014) and postoperatively ( P = .010). All 37 responders remained improved at follow-up whereas 42 of 59 (71%) of nonresponders ultimately improved ( P < .001). All other clinical characteristics, including dose and duration, were similar between groups. CONCLUSION: A response to steroids before surgery is highly predictive of long-term improvement postoperatively in brain metastasis patients with focal neurological deficits. Lack of a response portends a somewhat less favorable prognosis. Duration and intensity of therapy do not seem to affect the likelihood of response.

Innovative growth and development of a neurological surgery residency cadaveric skull base simulation training program: A single institution experience.

OBJECTIVE: Neurosurgical cadaveric and simulation training is a valuable opportunity for residents and fellows to develop as neurosurgeons, further neuroanatomy knowledge, and develop decision-making and technical expertise. The authors describe the growth and development of Oregon Health & Science University (OHSU) Department of Neurological Surgery (NSG) resident hands-on simulation skull base course and provide details of course layout and setup. METHODS: A three-part surgical simulation series was created to provide training in cadaveric skull base procedures. Course objectives were outlined for participants. Residents participated in NSG hands-on simulation courses (years 2015-2020) and completed annual course curriculum and anonymous course evaluations, which included free text reviews. Courses were evaluated by Likert scale analysis within Python, and free text was quantified using Valence Aware Dictionary for sEntiment Reasoning (VADER). Descriptive statistics were calculated and plotted using Python's Seaborn and Matplotlib library modules. RESULTS: Analysis included 162 skull base (anterior fossa, middle fossa and lateral, and endoscopic endonasal-based) simulation course evaluations. Resident responses were overwhelmingly positive. Likert responses demonstrated high average responses for each question (4.62 ± 0.56 and above). A positive attitude about simulation courses is supported by an average compound sentiment value of 0.558 ± 0.285. CONCLUSION: This is the first time Likert responses and sentiment analysis have been used to demonstrate how neurosurgical residents view a comprehensive, multi-year hands-on simulation training program. We hope the information presented serves as a guide for other institutions to develop their own residency educational curriculum in cadaveric skull base procedures.

Defining the Clival Recess Surgical Corridor and Clival Classification System for Approach to Sellar Pathology.

BACKGROUND: Sellar masses within the pars intermedius, bordered anteriorly by normal pituitary gland/stalk, and/or with ectatic cavernous carotid anatomy are challenging and high risk when approached through the endonasal standard direct/anterior sellar approach. This approach portends itself to a higher risk of pituitary gland/stalk injury and subtotal resection with the aforementioned anatomic variants. OBJECTIVE: To describe the indirect clival recess corridor approach to sellar lesions. This corridor is a "silent" point of access to lesions in this region endoscopically. While skull base teams may have used this approach to some degree, it has not yet been described in the literature to our knowledge. METHODS: We defined the clival recess surgical corridor with skull base craniometric measurements and use a case example with aberrant anatomy to illustrate the approach. We cross-sectionally reviewed 42 patients with sellar and suprasellar masses. To describe the approach's anatomy, we devised and defined the terms dorsum sella plumb line, anatomic corridor, angle of osseous, and operative corridor. RESULTS: Created novel clival aeration grade informing surgical planning. Classified clival aeration as Grade 1 (100%-75% aeration), Grade 2 (75%-50% aeration), Grade 3 (50%-25% aeration), and Grade 4 (25%-0% aeration). This classification system determines extent of drilling of the clivus required to optimize the clival recess corridor approach and its limitations. CONCLUSION: The clival recess surgical corridor is effective for accessing pituitary lesions within the sella. Consider the indirect approach when a standard direct/anterior sellar approach has high risk for vascular injury and/or endocrinological dysfunction.

Venous Sinus Stenting: Safety and Health Care Resource Evaluation for Optimal Recovery in an Evolving Health Care Environment.

BACKGROUND: Increasing evidence supports the effectiveness of venous sinus stenting (VSS) with favorable outcomes, safety, and expenses compared with shunting for idiopathic intracranial hypertension. Yet, no evidence is available regarding optimal postoperative recovery, which has increasing importance with the burdens on health care imposed by the coronavirus disease 2019 pandemic. We examined adverse events and costs after VSS and propose an optimal recovery pathway to maximize patient safety and reduce stress on health care resources. METHODS: A retrospective review was undertaken of elective VSS operations performed from May 2008 to August 2021 at a single institution. Primary data included hospital length of stay, intensive care unit (ICU) length of stay, adverse events, need for ICU interventions, and hospital costs. RESULTS: Fifty-three patients (98.1% female) met the inclusion criteria. Of these patients, 51 (96.2%) were discharged on postoperative day (POD) 1 and 2 patients were discharged on POD 2. Both patients discharged on POD 2 remained because of groin hematomas from femoral artery access. There were no major complications or care that required an ICU. Eight patients (15.1%) were lateralized to other ICUs or remained in a postanesthesia care unit because the neurosciences ICU was above capacity. Total estimated cost for initial recovery day in a neurosciences ICU room was $2361 versus $882 for a neurosurgery/neurology ward room. In our cohort, ward convalescence would save an estimated $79,866 for bed placement alone and increase ICU bed availability. CONCLUSIONS: Our findings reaffirm the safety of VSS. These patients should recover on a neurosurgery/neurology ward, which would save health care costs and increase ICU bed availability.

Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms - SCENT: 3-year outcomes.

BACKGROUND: To report the 3-year safety and effectiveness of the Surpass Streamline flow diverter in the SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms). METHODS: The Surpass Streamline flow diverter device was evaluated in a multicenter, prospective, single-arm, non-randomized interventional trial including patients with uncoilable or previously treated but failed aneurysms of the intracranial internal carotid artery. 3-year outcomes were tabulated with descriptive statistics and compared with 1-year outcomes. RESULTS: Of 180 patients in the modified intent-to-treat (mITT) cohort, 36-month clinical and angiographic follow-up was available in 134 and 117 cases, respectively. Effectiveness endpoint of complete aneurysm occlusion without clinically significant stenosis or retreatment was met in 71.8% (79/110, 95% CI 62.4% to 80.0%) of cases. Safety composite endpoint was 12.2% (22/180) over the 3-year period, with two major safety events (ipsilateral ischemic strokes) occurring between 12-36 months. Complete aneurysm occlusion was noted in 77.8% (91/117), and 99.1% (116/117) of the patients demonstrated adequate aneurysm occlusion (complete occlusion or neck residual). There were four cases (2.2%) of aneurysm rupture, all occurring within the first month of the index procedure. Target aneurysm retreatment rate was 2.8% (5/180). CONCLUSION: The present findings support the long-term safety and effectiveness of the Surpass Streamline flow diverter device. TRIAL REGISTRATION: NCT01716117.

A technical note on anterolateral mobilization in vertebrobasilar dolichoectasia for relief of brainstem compression.

Vascular compression of neural tissue causing neurological symptoms is a wellknown phenomenon. This is commonly seen in trigeminal neuralgia and, less commonly, in hemifacial spasm by small arteries, which can be treated by microvascular decompression. Rarely, larger arteries, such as the vertebral arteries, may compress the brainstem. This can lead to symptoms of pontine or medullary distress like hemiparesis, dysphagia, or respiratory distress. This is treated by macrovascular decompression. Due to the rare and heterogenous nature of this disease, there is no standardized approach. We describe a novel technique whereby the vertebrobasilar system is mobilized anterolaterally towards the occipital condyle with a sling to decompress the brainstem.
We report two cases of vertebrobasilar dolichoectasia causing brainstem compression. A carotid patch graft sling with anterolateral mobilization to the occipital condyle is described as a surgical nuance to macrovascular decompressive surgery. Briefly, the vertebral artery was identified and dissected away from the brainstem and the bulbar cranial nerves. Bovine pericardium graft was used to create a sling around the artery by suturing the two ends together. The sling was then fixed either to the occipital condyle using cranial plating screws or suturing to the dura of the occipital condyle.
A novel surgical technique for management of vertebrobasilar dolichoectasia causing brainstem compression with progressive neurological deterioration is reported. Anatomical location and the offending vessel should guide neurosurgeons to select the best surgical option to achieve complete decompression of the involved neural structures.

Operative Technique: Angiomatoid Fibrous Histiocytoma-Unique Case and Management.

Objective We describe the first jugular foramen angiomatoid fibrous histiocytoma (AFH) case and the first treatment with preoperative endovascular embolization. AFH is a rare intracranial neoplasm, primarily found in pediatric patient extremities. With an increase in AFH awareness and a well-described genetic profile, intracranial prevalence has also subsequently increased. Study Design We compare this case to previously reported cases using PubMed/Medline literature search, which was performed using the algorithm ["intracranial" AND "angiomatoid fibrous histiocytoma"] through December 2020 (23 manuscripts with 46 unique cases). Patient An 8-year-old female presented with failure to thrive and right-sided hearing loss. Work-up revealed an absence of right-sided serviceable hearing and a large jugular foramen mass. Angiogram revealed primary arterial supply from the posterior branch of the ascending pharyngeal artery, which was preoperatively embolized. Intervention Gross total resection was performed via a translabyrinthine approach. Conclusion The case presented is unique; the first reported AFH at the jugular foramen and the first reported case utilizing preoperative embolization. Preoperative embolization is a relatively safe technique that can improve the surgeon's ability to perform a maximally safe resection, which may decrease the need for adjuvant radiation in rare skull base tumors in young patients.

Endoscopic Endonasal Eustachian Tube Obliteration as a Treatment for Tension Pneumocephalus After Translabyrinthine Resection of Vestibular Schwannoma.

OBJECTIVE: Cerebrospinal fluid leak and pneumocephalus are rare but potentially devastating complications associated with translabyrinthine resection of cerebellopontine angle masses. Persistent pneumocephalus despite proximal eustachian tube (ET) obliteration is rare. We describe, to our knowledge, the first report of successful management of tension pneumocephalus by endoscopic endonasal ET obliteration using a novel V-loc (Covidien; Medtronic, Minneapolis, MN) suture technique. PATIENTS: A 63-year-old man presented with altered mental status 10 months after translabyrinthine excision of a left cerebellopontine angle vestibular schwannoma measuring 2.8 × 2.9 × 3.3 cm. Computed tomography demonstrated diffuse ventriculomegaly and new pneumocephalus along the right frontal lobe, lateral ventricles, and third ventricle, and air within the left translabyrinthine resection cavity. INTERVENTION: The patient underwent left-sided endoscopic endonasal ET obliteration using 2-0, 9-inch V-loc suture. MAIN OUTCOME MEASURE: Postoperatively, the patient's mental status improved with a decrease in size of the lateral and third ventricles on computed tomography. CONCLUSION: Endoscopic endonasal ET obliteration, a technique previously applied to recalcitrant cerebrospinal fluid leaks, is a safe and reasonable alternative to reentering the original surgical site for patients with pneumocephalus after lateral skull base surgery. Utilizing a V-loc suture for this technique instead of a traditional suture may improve procedural ease and speed.

Safety of intra-arterial chemotherapy with or without osmotic blood-brain barrier disruption for the treatment of patients with brain tumors.

Background: Intra-arterial administration of chemotherapy with or without osmotic blood-brain barrier disruption enhances delivery of therapeutic agents to brain tumors. The aim of this study is to evaluate the safety of these procedures. Methods: Retrospectively collected data from a prospective database of consecutive patients with primary and metastatic brain tumors who received intra-arterial chemotherapy without osmotic blood-brain barrier disruption (IA) or intra-arterial chemotherapy with osmotic blood-brain barrier disruption (IA/OBBBD) at Oregon Health and Science University (OHSU) between December 1997 and November 2018 is reported. Chemotherapy-related complications are detailed per Common Terminology Criteria for Adverse Events (CTCAE) guidelines. Procedure-related complications are grouped as major and minor. Results: 4939 procedures (1102 IA; 3837 IA/OBBBD) were performed on 436 patients with various pathologies (primary central nervous system lymphoma [26.4%], glioblastoma [18.1%], and oligodendroglioma [14.7%]). Major procedure-related complications (IA: 12, 1%; IA/OBBBD: 27, 0.7%; P = .292) occurred in 39 procedures including 3 arterial dissections requiring intervention, 21 symptomatic strokes, 3 myocardial infarctions, 6 cervical cord injuries, and 6 deaths within 3 days. Minor procedure-related complications occurred in 330 procedures (IA: 41, 3.7%; IA/OBBBD: 289, 7.5%; P = .001). Chemotherapy-related complications with a CTCAE attribution and grade higher than 3 was seen in 359 (82.3%) patients. Conclusions: We provide safety and tolerability data from the largest cohort of consecutive patients who received IA or IA/OBBBD. Our data demonstrate that IA or IA/OBBBD safely enhance drug delivery to brain tumors and brain around the tumor.

Endoscopic Endonasal Eustachian Tube Obliteration for Cerebrospinal Fluid Rhinorrhea: A Case Series and Scoping Review.

BACKGROUND: Endoscopic endonasal eustachian tube obliteration (EEETO) is a valuable option for treating cerebrospinal fluid rhinorrhea (CSFR) after lateral skull base surgery. Several small case series describe different techniques because of the rarity of this indication. OBJECTIVE: To review available literature on EEETO focusing on technique and factors affecting success. We also contribute a new case series using a knotless barbed suture technique. METHODS: This was a retrospective chart review of EEETO using barbed suture for CSFR at our institution from 2018 to 2021. Scoping review was performed by searching PubMed for articles on EEETO for CSFR. Patients were pooled for data syntheses. RESULTS: Our retrospective series contained 7 patients. Two patients (28.6%) required revision, but all were ultimately successful. Six studies were identified in scoping review for a combined total of 23 patients. Most of the patients initially underwent translabyrinthine (52.2%) resection of vestibular schwannoma (82.6%). Average time to initial CSFR was 362.6 days (standard deviation ± 1034.2, range 0-4320 days). Twenty-two patients underwent lumbar drain, and 11 underwent prior surgical attempts before EEETO. The initial success rate of EEETO was 65.2%. In 8 patients needing revision, EEETO was ultimately successful in 6. There were no differences in demographics or presentation between successful and revision cases. Seven different techniques were described. CONCLUSION: EEETO can treat CSFR after lateral skull base surgery. Revision surgery is common and difficult to predict. Several techniques have been described, and utilization of barbed suture is a viable method with comparable success, but without the need for endoscopic knot tying.

Prospective biomarker study in newly diagnosed glioblastoma: Cyto-C clinical trial.

BACKGROUND: Glioblastoma (GBM) has a 5-year survival rate of 3%-5%. GBM treatment includes maximal resection followed by radiotherapy with concomitant and adjuvant temozolomide (TMZ). Cytochrome C oxidase (CcO) is a mitochondrial enzyme involved in the mechanism of resistance to TMZ. In a prior retrospective trial, CcO activity in GBMs inversely correlated with clinical outcome. The current Cyto-C study was designed to prospectively evaluate and validate the prognostic value of tumor CcO activity in patients with newly diagnosed primary GBM, and compared to the known prognostic value of MGMT promoter methylation status. METHODS: This multi-institutional, blinded, prospective biomarker study enrolled 152 patients with newly diagnosed GBM who were to undergo surgical resection and would be candidates for standard of care. The primary end point was overall survival (OS) time, and the secondary end point was progression-free survival (PFS) time. Tumor CcO activity and MGMT promoter methylation status were assayed in a centralized laboratory. RESULTS: OS and PFS did not differ by high or low tumor CcO activity, and the prognostic validity of MGMT promoter methylation was confirmed. Notably, a planned exploratory analysis suggested that the combination of low CcO activity and MGMT promoter methylation in tumors may be predictive of long-term survival. CONCLUSIONS: Tumor CcO activity alone was not confirmed as a prognostic marker in GBM patients. However, the combination of low CcO activity and methylated MGMT promoter may reveal a subgroup of GBM patients with improved long-term survival that warrants further evaluation. Our work also demonstrates the importance of performing large, multi-institutional, prospective studies to validate biomarkers. We also discuss lessons learned in assembling such studies.

Determinants of survival in sinonasal and skull base chondrosarcoma: An analysis of the National Cancer Database.

BACKGROUND: Chondrosarcomas are rare, malignant chondroid tumors that can occur in the sinonasal and skull base regions. Surgery is a mainstay of treatment, but complete resection can be challenging because of the close proximity of critical neurovascular structures. Because of their rarity and relatively indolent nature, optimal treatment regimens are not established. Our objective was to assess determinants of survival for sinonasal and skull base chondrosarcomas utilizing the National Cancer Database (NCDB). METHODS: The NCDB (2004-2017) was queried for cases of sinonasal and skull base chondrosarcoma. Multivariate hazard regression modeling was used to identify significant predictors of 60-month and 120-month overall survival (OS). RESULTS: Seven hundred thirty-six cases met inclusion criteria. OS for all treatment types was 84.7% [SE±0.02] at 60 months and 75.6% [SE±0.02] at 120 months. Surgery with or without adjuvant treatment was found to associate with highest OS at 60 and 120 months. For patients receiving adjuvant radiation during treatment, proton therapy had significantly better OS at 60 months (95.4% [SE±0.03] vs 82.3% [SE±0.03], -2  = 5.27; p = 0.02) and 120 months (85.1% [SE±0.08] vs 72.8% [SE±0.05], -2  = 4.11; p = 0.04) compared with conventional external beam. After adjustment for primary site, multivariate Cox regression modeling (n = 561) identified cofactors significantly associated with variation in mortality risk at 60 and 120 months, including age, Charlson-Deyo total score ≥ 3, insurance provision status, and tumor grade. CONCLUSIONS: Sinonasal and skull base chondrosarcoma are primarily treated with surgery with favorable OS. Adjuvant treatment may be required and proton radiation was associated with improved 60-month and 120-month survival compared with conventional radiation.

Opioid use after endoscopic skull base surgery: A descriptive, prospective, longitudinal cohort study.

BACKGROUND: Opioid abuse is a public health crisis and the perioperative period can be a time of first opioid exposure. Little is known about postoperative pain management after endoscopic skull base surgery (ESBS). METHODS: This investigation was a single-institution, longitudinal, prospective cohort study of adult patients undergoing ESBS between November 2019 and March 2020. Participants completed preoperative questionnaires and were contacted every 48 hours postoperatively to quantify pain and opioid consumption. RESULTS: A total of 33 patients were enrolled and 28 of 33 patients (85%) underwent ESBS for sellar pathology. Mean total morphine milligram equivalents (MME) consumed was 381.9 ± 476.0. History of a headache disorder (p = 0.025) and previous opioid use within 60 days preoperatively (p < 0.001) were significantly associated with greater opioid use. Mean duration of opioid use was 6.7 ± 5.1 (range, 0-20) days. Headache disorder (p = 0.01), depression (p = 0.03), anxiety (p = 0.03), age ≤46 years (p = 0.029), and previous opioid use (p = 0.008) were all associated with longer mean opioid use. Patients with headache disorder also reported higher mean postoperative pain scores. Fewer than half of the participants required opioids by postoperative day 8. Prescription of nonsteroidal anti-inflammatory drugs at discharge was significantly associated with less outpatient opioid use (p = 0.032). At 2-month follow-up, 37% of patients reported keeping excess opioids. CONCLUSION: After ESBS, greater total opioid use was significantly associated with history of headaches and previous opioid use within 60 days. Overall, opioid use declined among all patients in the postoperative period, but several factors may contribute to longer duration of use.

Trigeminal Neuralgia Secondary to Compression by a Microsurgical Aneurysm Clip.

Microvascular decompression (MVD) is a common surgical technique used for treatment of trigeminal neuralgia (TN) caused by direct vascular compression of the nerve at the brainstem entry zone (BEZ). Here we report a case of a patient (status postcraniotomy for microsurgical clip obliteration of a ruptured mid-basilar artery aneurysm) who developed right-sided TN 6 years after the procedure. During MVD surgery the clip head was found to be compressing the trigeminal nerve at the BEZ, causing Type 1 TN in V3 distribution. This is consistent with the commonly held theory that a pulsatile stimulus is needed to cause TN. To our knowledge there are no previous reports in the literature of an instrument causing TN.

Development of a Cadaveric Multiport Model of Posterior Circulation Aneurysm Clipping for Neurosurgery and Otolaryngology Residents.

Posterior circulation aneurysms are difficult to treat with the current methods of coiling and clipping. To address limitations in training, we developed a cadaveric model to train learners on endoscopic clipping of posterior circulation aneurysms. An endoscopic transclival approach (ETA) and a transorbital precaruncular approach (TOPA) to successfully access and clip aneurysms of the posterior circulation are described. The model has flexibility in that a colored silicone compound can be injected into the cadaveric vessels for the purpose of training learners on vascular anatomy. The other option is that the model could be connected to a vascular perfusion pump allowing real-time appreciation of a pulsatile or ruptured aneurysm. This cadaveric model is the first of its kind for training of endoscopic clipping of posterior circulation aneurysms. Learners will develop proficiency in endoscopic skills, appropriate dissection, and appreciation for relative anatomy while developing an algorithm that can be employed in a real operative arena. Going forward, various clinical scenarios can be developed to enhance the realism, allow learners from different specialties to work together, and emphasize the importance of teamwork and effective communication.

Cerebrospinal Fluid Hypovolemia: A Case Report of a Red Herring.

Mild intracranial hypotension can lead to classically recognizable symptoms such as positional headaches, nausea, vomiting, and occasionally blurred vision. Less commonly, severe cerebrospinal fluid (CSF) hypovolemia can lead to a life-threatening condition that mimics intracranial hypertension, including transtentorial herniation and subsequent rapid neurologic decline. In this report we present a unique case of severe intracranial hypotension from a thoracic tumor resection that led to symptoms initially mistaken for intracranial hypertension, however ultimately correctly diagnosed as severe CSF hypovolemia that improved with dural repair. Additionally, we describe a rare angiography finding associated with CSF hypovolemia, kinking of the basilar artery. Here we report a 47-year-old female with neurofibromatosis Type 2 found to have a T3 intradural extramedullary tumor. She initially presented with urinary incontinence and gait/balance difficulty. She underwent thoracic laminectomies at T3 and T4 for the excision of the lesion. She was discharged on postoperative day 4. On postoperative day 9, she was noted to have nausea, vomiting, and decreased consciousness. Head computed tomography (CT) demonstrated acute downward herniation. She was transferred to our institution from a community facility obtunded and was intubated for airway protection. She was placed in the Trendelenburg position with immediate improvement, and declined every time her head was raised. Angiogram showed significant kinking of her basilar artery. A CT myelogram revealed a CSF leak from her recent thoracic surgery. She underwent exploration of her thoracic wound, and a ventral durotomy was repaired. Following this, she began to tolerate the head of bed elevations and recovered back to her neurologic baseline. A postoperative head CT angiography obtained before discharge showed improvement of her basilar kink. Mild intracranial hypotension is a common finding in patients who undergo procedures that enter the CSF space. Severe intracranial hypotension can easily be missed diagnosed as the signs on the exam are similar to patients with signs of intracranial hypertension. It is of paramount importance that the clinician recognizes brain sag, as the treatment algorithms are vastly different from that of intracranial hypertension leading to transtentorial herniation.