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OBJECTIVE There is a reported elevated risk of cerebral aneurysms in patients with intracranial dural arteriovenous fistulas (dAVFs). However, the natural history, rate of spontaneous regression, and ideal treatment regimen are not well characterized. In this study, the authors aimed to describe the characteristics of patients with dAVFs and intracranial aneurysms and propose a classification system. METHODS The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database from 12 centers was retrospectively reviewed. Analysis was performed to compare dAVF patients with (dAVF+ cohort) and without (dAVF-only cohort) concomitant aneurysm. Aneurysms were categorized based on location as a dAVF flow-related aneurysm (FRA) or a dAVF non–flow-related aneurysm (NFRA), with further classification as extra- or intradural. Patients with traumatic pseudoaneurysms or aneurysms with associated arteriovenous malformations were excluded from the analysis. Patient demographics, dAVF anatomical information, aneurysm information, and follow-up data were collected. RESULTS Of the 1077 patients, 1043 were eligible for inclusion, comprising 978 (93.8%) and 65 (6.2%) in the dAVF-only and dAVF+ cohorts, respectively. There were 96 aneurysms in the dAVF+ cohort; 10 patients (1%) harbored 12 FRAs, and 55 patients (5.3%) harbored 84 NFRAs. Dural AVF+ patients had higher rates of smoking (59.3% vs 35.2%, p < 0.001) and illicit drug use (5.8% vs 1.5%, p = 0.02). Sixteen dAVF+ patients (24.6%) presented with aneurysm rupture, which represented 16.7% of the total aneurysms. One patient (1.5%) had aneurysm rupture during follow-up. Patients with dAVF+ were more likely to have a dAVF located in nonconventional locations, less likely to have arterial supply to the dAVF from external carotid artery branches, and more likely to have supply from pial branches. Rates of cortical venous drainage and Borden type distributions were comparable between cohorts. A minority (12.5%) of aneurysms were FRAs. The majority of the aneurysms underwent treatment via either endovascular (36.5%) or microsurgical (15.6%) technique. A small proportion of aneurysms managed conservatively either with or without dAVF treatment spontaneously regressed (6.2%). CONCLUSIONS Patients with dAVF have a similar risk of harboring a concomitant intracranial aneurysm unrelated to the dAVF (5.3%) compared with the general population (approximately 2%–5%) and a rare risk (0.9%) of harboring an FRA. Only 50% of FRAs are intradural. Dural AVF+ patients have differences in dAVF angioarchitecture. A subset of dAVF+ patients harbor FRAs that may regress after dAVF treatment.

INTRODUCTION: National and international trends continue to show greater emphasis on endovascular techniques for the treatment of cerebrovascular disease. The cerebrovascular neurosurgeon however must be adequately equipped to treat these patients via both open and endovascular techniques. METHODS: The decline in open cerebrovascular cases for aneurysm clipping has forced many trainees to pursue open cerebrovascular fellowships to increase case volume. An alternative strategy has been employed at our institution, which is early identification of subspecialty focus with resident driven self-selection of open cerebrovascular cases. RESULTS: This has allowed recent graduates to obtain enfolded endovascular training and a significant number of open cerebrovascular cases in order to obtain competence and exposure. DISCUSSION: We advocate for further self-selection paradigms supplemented with simulation training in order to obviate the need for extended post-residency fellowships.

Management of degenerative disease of the spine has evolved to favor minimally invasive techniques, including nonrobotic-assisted and robotic-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Value-based spending is being increasingly implemented to control rising costs in the US healthcare system. With an aging population, it is fundamental to understand which procedure(s) may be most cost-effective.To compare robotic and nonrobotic MIS-TLIF through a cost-utility analysis.We considered direct medical costs related to surgical intervention and to the hospital stay, as well as 1-yr utilities. We estimated costs by assessing all cases involving adults undergoing robotic surgery at a single institution and an equal number of patients undergoing nonrobotic surgery, matched by demographic and clinical characteristics. We adopted a willingness to pay of $50 000/quality-adjusted life year (QALY). Uncertainty was addressed by deterministic and probabilistic sensitivity analyses.Costs were estimated based on a total of 76 patients, including 38 undergoing robot-assisted and 38 matched patients undergoing nonrobot MIS-TLIF. Using point estimates, robotic surgery was projected to cost $21 546.80 and to be associated with 0.68 QALY, and nonrobotic surgery was projected to cost $22 398.98 and to be associated with 0.67 QALY. Robotic surgery was found to be more cost-effective strategy, with cost-effectiveness being sensitive operating room/materials and room costs. Probabilistic sensitivity analysis identified robotic surgery as cost-effective in 63% of simulations.Our results suggest that at a willingness to pay of $50 000/QALY, robotic-assisted MIS-TLIF was cost-effective in 63% of simulations. Cost-effectiveness depends on operating room and room (admission) costs, with potentially different results under distinct neurosurgical practices.

Incidental durotomy is a known complication of spinal surgery. Persistent cerebrospinal fluid (CSF) leak after unrecognized durotomy may lead to prolonged hospitalization and significant morbidity. If initial bed rest fails, the surgeon must choose between nontargeted methods such as oversewing the wound and lumbar drain placement or return to the operating room.To report the novel use of color flow doppler (CFD) in conjunction with ultrasound (US) to localize the point of CSF leak, assist with aspiration of the pseudomeningocele, and direct the application of fibrin sealant or epidural blood patch.This article includes a description of the technique as a technical note.A 72-year-old man underwent L2-5 laminectomies for spinal stenosis. During the index operation, a durotomy occurred and was repaired primarily. The patient subsequently developed leg weakness, back pain, and bulging of the incision. Using CFD, the site of durotomy was determined. Under direct visualization, 34 mL of CSF was aspirated from the pseudomeningocele and 20 mL of fibrin sealant was placed opposing the durotomy. At 2-month follow-up, CFD confirmed absent flow and MRI demonstrated pseudomeningocele resolution.This article represents the first report highlighting the utility of CFD US to guide epidural patch placement for postsurgical CSF leaks. CFD allows localization of the durotomy and direct application of blood or fibrin sealant, potentially increasing the success rate of epidural blood patch in postoperative patients. This approach is less invasive than revision surgery and does not require the prolonged hospitalization of lumbar drainage or other nontargeted interventions.

Background and purpose Acute ischemic stroke has increasingly become a procedural disease following the demonstrated benefit of mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO) on clinical outcomes and tissue salvage in randomized trials. Given these data and anecdotal experience of decreased numbers of decompressive hemicraniectomies (DHCs) performed for malignant cerebral edema, we sought to correlate the numbers of strokes, thrombectomies, and DHCs performed over the timeline of the 2013 failed thrombolysis/thrombectomy trials, to the 2015 modern randomized MT trials, to post-DAWN and DEFUSE 3. Materials and methods This is a multicenter retrospective compilation of patients who presented with ELVO in 11 US high-volume comprehensive stroke centers. Rates of tissue plasminogen activator (tPA), thrombectomy, and DHC were determined by current procedural terminology code, and specificity to acute ischemic stroke confirmed by each institution. Endpoints included the incidence of stroke, thrombectomy, and DHC and rates of change over time. Results Between 2013 and 2018, there were 55,247 stroke admissions across 11 participating centers. Of these, 6145 received tPA, 4122 underwent thrombectomy, and 662 patients underwent hemicraniectomy. The trajectories of procedure rates over time were modeled and there was a significant change in MT rate ( p = 0.002) without a concomitant change in the total number of stroke admissions, tPA administration rate, or rate of DHC. Conclusions This real-world study confirms an increase in thrombectomy performed for ELVO while demonstrating stable rates of stroke admission, tPA administration and DHC. Unlike prior studies, increasing thrombectomy rates were not associated with decreased utilization of hemicraniectomy.

Background: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. Methods: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. Results: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2–14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3–5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7–12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4–37.7; P , 0.026). Conclusions: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

OBJECTIVEInhibition of platelet aggregation is universally used to prevent thromboembolic complications related to stent placement in endovascular neurosurgery, but excessive inhibition potentiates hemorrhagic complications. Previously, the authors demonstrated that two different commercially available measures of adenosine diphosphate (ADP)–dependent platelet inhibition—the VerifyNow P2Y12 clopidogrel assay (measured in platelet reactivity units [PRU]) and maximal amplitude (MA) attributable to ADP activity (MA-ADP) derived from thromboelastography (TEG) with platelet mapping (PM)—yielded wildly different results. This study sought to analyze observed complications to quantify the ideal therapeutic windows for both tests.METHODSNinety-one patients with simultaneous or near-simultaneous PRU and TEG-PM results who underwent craniocervical endovascular stenting at the authors’ institution between September 2015 and November 2017 were identified and retrospectively enrolled. From November 2017 until June 2019, 109 additional patients were prospectively enrolled. For this study, in-hospital thrombotic and hemorrhagic complications (both CNS and non-CNS) were tabulated, and receiver operating characteristic (ROC) curve analysis was used to identify threshold values of the PRU and MA-ADP for predicting each type of complication.RESULTSOf the 200 patients enrolled, 7 were excluded because of anemia or thrombocytopenia outside of the test manufacturer’s specified ranges and 1 was excluded because they did not have a TEG-PM result. Including complications of all severities, there were a total of 15 CNS thrombotic complications, 1 access-site thrombotic complication, 3 CNS hemorrhages, 8 access-site hemorrhagic complications, and 3 hemorrhagic complications not affecting either the CNS or the access site. ROC curve analysis yielded therapeutic threshold values of 118–144 PRU. The results demonstrated PRU has a significant dose-dependent effect on the rates of thrombosis and hemorrhage. Logistic regression models did not demonstrate statistically significant relationships between the MA-ADP and either thrombosis or hemorrhage. ROC analysis based on these models is of little value and did not identify significant threshold values for MA-ADP.CONCLUSIONSThere continues to be poor correlation between the results of TEG-PM and PRU. PRU accurately predicted complications, with a relatively narrow ideal value range of 118–144. The MA-ADP alone does not appear able to accurately predict either hemorrhagic or thrombotic complications in this group.

Background Burnout is a negative workplace syndrome of emotional exhaustion, cynicism, and perceived professional inefficacy that risks the patient-provider relationship, patient care, and physician well-being. Objective To assimilate the neurosurgical burnout literature in order to classify burnout among domestic and international neurosurgeons and trainees, identify contributory factors, and appraise the impact of wellness programs. Methods A scoping review identified the available literature, which was reviewed for key factors related to burnout among neurosurgeons. Two researchers queried PubMed, Embase, Google Scholar, Cochrane, and Web of Science for articles on burnout in neurosurgery and reduced 1610 results to 32 articles. Results A total of 32 studies examined burnout in neurosurgery. A total of 26 studies examined prevalence and 8 studies detailed impact of wellness programs. All were published after 2011. Burnout prevalence was measured mostly through the Maslach Burnout Inventory (n = 21). In 4 studies, participants defined their own understanding of "burnout." Domestically, burnout prevalence was 11.2% to 67% among residents and 15% to 57% among attendings. Among trainees, poor operative experience, poor faculty relationships, and social stressors were burnout risks but not age, sex, or marital status. Among attendings, the literature identified financial or legal concerns, lack of intellectual stimulation, and poor work-life balance as risks. The impact of wellness programs on trainees is unclear but group exercises may offer the most benefit. Conclusion Noticeable methodological differences in studies on trainee and attending burnout contribute to a wide range of neurosurgery burnout estimates and yield significant knowledge gaps. Environment may have greater impact on trainee burnout than demographics. Wellness programs should emphasize solidarity.

Background Minimally invasive lateral lumbar interbody fusion (LLIF) offers advantages over traditional approaches, providing indirect decompression of neural elements and deformity correction while avoiding many challenges and risks of anterior and posterior approaches. Mastering this technique requires a specialized team, advanced equipment, and sufficient case exposure. Current training is limited to the classic educational model, and alternative training methods such as cadaver labs can be inconvenient, inaccessible, expensive, and incompatible with intraoperative neuromonitoring (IONM) systems. Objective The aim of this study was to create a proof-of-concept, low-cost, fully synthetic lateral lumbar surgical simulator and to increase awareness of the lack of current training alternatives. Methods Standard engineering design and expert interviews of attending neurosurgeons, nurses, engineers, and medical device representatives (n=20) were utilized to determine key elements for the simulator, physical characteristics of the components, and translational strategy. Physical and radiographic testing was performed on multiple thermoplastics to determine appropriateness for inclusion in the simulator. For evaluation of the concept, a descriptive slide deck and questionnaire were sent to 15 U.S. and 15 international surgeons who perform LLIF. Results The lateral access training model (LATM) features the following three components: torso casing, spine module, and IONM feature. This model utilizes operable ABS (acrylonitrile butadiene styrene) 3D-printed lumbar vertebrae, verified for anatomical accuracy and compatibility with fluoroscopy. Additionally, a novel neuromonitoring simulation algorithm was developed to train junior residents on neurological complications. To further highlight the need for lateral training models, 30/30 polled surgeons felt that this simulator has value for the field, 29/30 noted that they would have used the LATM if they had access during training, and 30/30 responded that they would encourage trainees to practice on the LATM. Conclusion The LATM is a first step to provide reliable and inexpensive basic lateral lumbar spine training. While this model is lacking some anatomical features, our simulator offers novel training elements for lateral lumbar transpsoas approaches, which lay the foundation for future models to be built. The need for this training exists, and current gaps in the approach to learning these complex techniques need to be filled due to the inconvenience, cost, and impracticability of standard cadaveric models.

OBJECTIVE Cranial dural arteriovenous fistulas (dAVFs) are often treated with endovascular therapy, but occasionally a multimodality approach including surgery and/or radiosurgery is utilized. Recurrence after an initial angiographic cure has been reported, with estimated rates ranging from 2% to 14.3%, but few risk factors have been identified. The objective of this study was to identify risk factors associated with recurrence of dAVF after putative cure. METHODS The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) data were retrospectively reviewed. All patients with angiographic cure after treatment and subsequent angiographic follow-up were included. The primary outcome was recurrence, with risk factor analysis. Secondary outcomes included clinical outcomes, morbidity, and mortality associated with recurrence. Risk factor analysis was performed comparing the group of patients who experienced recurrence with those with durable cure (regardless of multiple recurrences). Time-to-event analysis was performed using all collective recurrence events (multiple per patients in some cases). RESULTS Of the 1077 patients included in the primary CONDOR data set, 457 met inclusion criteria. A total of 32 patients (7%) experienced 34 events of recurrence at a mean of 368.7 days (median 192 days). The recurrence rate was 4.5% overall. Kaplan-Meier analysis predicted long-term recurrence rates approaching 11% at 3 years. Grade III dAVFs treated with endovascular therapy were statistically significantly more likely to experience recurrence than those treated surgically (13.3% vs 0%, p = 0.0001). Tentorial location, cortical venous drainage, and deep cerebral venous drainage were all risk factors for recurrence. Endovascular intervention and radiosurgery were associated with recurrence. Six recurrences were symptomatic, including 2 with hemorrhage, 3 with nonhemorrhagic neurological deficit, and 1 with progressive flow-related symptoms (decreased vision). CONCLUSIONS Recurrence of dAVFs after putative cure can occur after endovascular treatment. Risk factors include tentorial location, cortical venous drainage, and deep cerebral drainage. Multimodality therapy can be used to achieve cure after recurrence. A delayed long-term angiographic evaluation (at least 1 year from cure) may be warranted, especially in cases with risk factors for recurrence.

OBJECTIVE Cranial dural arteriovenous fistulas (dAVFs) are rare lesions, hampering efforts to understand them and improve their care. To address this challenge, investigators with an established record of dAVF investigation formed an international, multicenter consortium aimed at better elucidating dAVF pathophysiology, imaging characteristics, natural history, and patient outcomes. This report describes the design of the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) and includes characterization of the 1077-patient cohort. METHODS Potential collaborators with established interest in the field were identified via systematic review of the literature. To ensure uniformity of data collection, a quality control process was instituted. Data were retrospectively obtained. RESULTS CONDOR comprises 14 centers in the United States, the United Kingdom, the Netherlands, and Japan that have pooled their data from 1077 dAVF patients seen between 1990 and 2017. The cohort includes 359 patients (33%) with Borden type I dAVFs, 175 (16%) with Borden type II fistulas, and 529 (49%) with Borden type III fistulas. Overall, 852 patients (79%) presented with fistula-related symptoms: 427 (40%) presented with nonaggressive symptoms such as tinnitus or orbital phenomena, 258 (24%) presented with intracranial hemorrhage, and 167 (16%) presented with nonhemorrhagic neurological deficits. A smaller proportion (224 patients, 21%), whose dAVFs were discovered incidentally, were asymptomatic. Many patients (85%, 911/1077) underwent treatment via endovascular embolization (55%, 587/1077), surgery (10%, 103/1077), radiosurgery (3%, 36/1077), or multimodal therapy (17%, 184/1077). The overall angiographic cure rate was 83% (758/911 treated), and treatment-related permanent neurological morbidity was 2% (27/1467 total procedures). The median time from diagnosis to follow-up was 380 days (IQR 120–1038.5 days). CONCLUSIONS With more than 1000 patients, the CONDOR registry represents the largest registry of cranial dAVF patient data in the world. These unique, well-annotated data will enable multiple future analyses to be performed to better understand dAVFs and their management.

OBJECTIVE Current evidence suggests that intracranial dural arteriovenous fistulas (dAVFs) without cortical venous drainage (CVD) have a benign clinical course. However, no large study has evaluated the safety and efficacy of current treatments and their impact over the natural history of dAVFs without CVD. METHODS The authors conducted an analysis of the retrospectively collected multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database. Patient demographics and presenting symptoms, angiographic features of the dAVFs, and treatment outcomes of patients with Borden type I dAVFs were reviewed. Clinical and radiological follow-up information was assessed to determine rates of new intracranial hemorrhage (ICH) or nonhemorrhagic neurological deficit (NHND), worsening of venous hyperdynamic symptoms (VHSs), angiographic recurrence, and progression or spontaneous regression of dAVFs over time. RESULTS A total of 342 patients/Borden type I dAVFs were identified. The mean patient age was 58.1 ± 15.6 years, and 62% were women. The mean follow-up time was 37.7 ± 54.3 months. Of 230 (67.3%) treated dAVFs, 178 (77%) underwent mainly endovascular embolization, 11 (4.7%) radiosurgery alone, and 4 (1.7%) open surgery as the primary modality. After the first embolization, most dAVFs (47.2%) achieved only partial reduction in early venous filling. Multiple complementary interventions increased complete obliteration rates from 37.9% after first embolization to 46.7% after two or more embolizations, and 55.2% after combined radiosurgery and open surgery. Immediate postprocedural complications occurred in 35 dAVFs (15.2%) and 6 (2.6%) with permanent sequelae. Of 127 completely obliterated dAVFs by any therapeutic modality, 2 (1.6%) showed angiographic recurrence/recanalization at a mean of 34.2 months after treatment. Progression to Borden-Shucart type II or III was documented in 2.2% of patients and subsequent development of a new dAVF in 1.6%. Partial spontaneous regression was found in 22 (21.4%) of 103 nontreated dAVFs. Multivariate Cox regression analysis demonstrated that older age, NHND, or severe venous-hyperdynamic symptoms at presentation and infratentorial location were associated with worse prognosis. Kaplan-Meier curves showed no significant difference for stable/improved symptoms survival probability in treated versus nontreated dAVFs. However, estimated survival times showed better trends for treated dAVFs compared with nontreated dAVFs (288.1 months vs 151.1 months, log-rank p = 0.28). This difference was statistically significant for treated dAVFs with 100% occlusion (394 months, log-rank p < 0.001). CONCLUSIONS Current therapeutic modalities for management of dAVFs without CVD may provide better symptom control when complete angiographic occlusion is achieved.

“Moral distress” describes the psychological strain a provider faces when unable to uphold professional values because of external constraints. Recurrent or intense moral distress risks moral injury, burnout, and physician attrition but has not been systematically studied among neurosurgeons. OBJECTIVE: To develop a unique instrument to test moral distress among neurosurgeons, evaluate the frequency and intensity of scenarios that may elicit moral distress and injury, and determine their impact on neurosurgical burnout and turnover. METHODS: An online survey investigating moral distress, burnout, and practice patterns was emailed to attending neurosurgeon members of the Congress of Neurological Surgeons. Moral distress was evaluated through a novel survey designed for neurosurgical practice. RESULTS: A total of 173 neurosurgeons completed the survey. Half of neurosurgeons (47.7%) reported significant moral distress within the past year. The most common cause was managing critical patients lacking a clear treatment plan; the most intense distress was pressure from patient families to perform futile surgery. Multivariable analysis identified burnout and performing ≥2 futile surgeries per year as predictors of distress (P < .001). Moral distress led 9.8% of neurosurgeons to leave a position and 26.6% to contemplate leaving. The novel moral distress survey demonstrated excellent internal consistency (Cronbach alpha = 0.89). CONCLUSION: We developed a reliable survey assessing neurosurgical moral distress. Nearly, half of neurosurgeons suffered moral distress within the past year, most intensely from external pressure to perform futile surgery. Moral distress correlated with burnout risk caused 10% of neurosurgeons to leave a position and a quarter to consider leaving.

Background: Spinal synovial cysts are cystic dilatations of synovial sheaths that extrude into the spinal canal. Despite their generally benign behavior, they can cause severe symptoms due to compression of neural structures. They are most commonly found in the lumbar spine and are rare in the cervical region, especially at the atlanto-occipital junction. Case Description: A 65-year-old presented with neck pain and headaches. The magnetic resonance imaging (MRI) revealed a degenerative cyst within the anterior foramen magnum causing anterior spinal cord and brainstem compression. Multiple surgical treatment options were discussed, and he was prescribed methylprednisolone and immobilization of his cervical spine with a rigid collar. One month later, the patient reported dramatic improvement of his symptoms, and no surgery was performed. One year later, his pain had remained much improved with the continued use of the collar and pain management (i.e., using anti-inflammatories and muscle relaxants). The 1-year follow-up MRI showed the atlanto-occipital cyst compressing the cervicomedullary junction had completely resolved along with the brainstem compression. Conclusion: A 65-year-old presented with myelopathy attributed to a large anterior foramen magnum atlanto-occipital cyst compressing the cord. Conservative management for 1 month with a rigid cervical collar and steroids resulted in marked neurological improvement; at 1 year follow-up, the patient was markedly improved with an MR that demonstrated spontaneous cyst regression.

Background and Purpose: Dural arteriovenous fistulae can present with hemorrhage, but there remains a paucity of data regarding subsequent outcomes. We sought to use the CONDOR (Consortium for Dural Arteriovenous Fistula Outcomes Research), a multi-institutional registry, to characterize the morbidity and mortality of dural arteriovenous fistula–related hemorrhage. Methods: A retrospective review of patients in CONDOR who presented with dural arteriovenous fistula–related hemorrhage was performed. Patient characteristics, clinical follow-up, and radiographic details were analyzed for associations with poor outcome (defined as modified Rankin Scale score ≥3). Results: The CONDOR dataset yielded 262 patients with incident hemorrhage, with median follow-up of 1.4 years. Poor outcome was observed in 17.0% (95% CI, 12.3%–21.7%) at follow-up, including a 3.6% (95% CI, 1.3%–6.0%) mortality. Age and anticoagulant use were associated with poor outcome on multivariable analysis (odds ratio, 1.04, odds ratio, 5.1 respectively). Subtype of hemorrhage and venous shunting pattern of the lesion did not affect outcome significantly. Conclusions: Within the CONDOR registry, dural arteriovenous fistula–related hemorrhage was associated with a relatively lower morbidity and mortality than published outcomes from other arterialized cerebrovascular lesions but still at clinically consequential rates.

Background: Spontaneous intracerebral hemorrhage (ICH) is a significant cause of morbidity and mortality worldwide. The development of venous thromboembolism (VTE), including deep venous thrombosis or pulmonary embolism, is correlated with negative outcomes following ICH. Due to the risk of hematoma expansion associated with the use of VTE chemoprophylaxis, there remains significant debate about the optimal timing for its initiation following ICH. We analyzed the risk of early chemoprophylaxis on hematoma expansion following ICH. Methods: We performed a retrospective analysis of patients presenting with spontaneous ICH at single institution between 2011 and 2018. The rate of hematoma expansion was compared between patients that received early chemoprophylaxis (on admission) and those that received conventional chemoprophylaxis (>24 h). Results: Data for 235 patients were available for analysis. Eleven patients (7.5%) in the early prophylaxis cohort and seven patients (8.0%) in the conventional prophylaxis cohort developed VTE (P = 0.9). Hematoma expansion also did not differ significantly (early 19%, conventional 23%, P = 0.5). Conclusion: The use of early chemoprophylaxis against venous thromboembolic events following ICH appears safe in our patient population without increasing the risk of hematoma expansion. Given the increased risk of poor outcome in the setting of VTE, early VTE chemoprophylaxis should be considered in patients who present with ICH. Larger, prospective, and randomized studies are necessary to better elucidate the risk of early chemoprophylaxis and potential reduction in venous thromboembolic events.

BACKGROUND: Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial.OBJECTIVE: To compare the outcomes of observation versus intervention for low-grade dAVFs.METHODS: We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up.RESULTS: The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort (P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively.CONCLUSION: Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.

Starting in the 1960s, ossification of the posterior longitudinal ligament (OPLL) became more commonly diagnosed in Japan. The disease is characterized by a gradual increase in calcification of the posterior longitudinal ligament with the eventual sequelae of cervical canal stenosis and myelopathy. Surgical interventions to relieve stenosis and neurologic symptoms are performed to decompress the cervical canal. Studies demonstrate continued ossification of the OPLL in both nonsurgical and surgically treated patients. In this review, the authors evaluate the epidemiology, pathophysiology, and literature regarding disease progression in OPLL after cervical fusion.

In this surgical video, the authors present a successful minimally invasive (MIS) lateral retroperitoneal transpsoas approach for resection of an L4 nerve root schwannoma. They describe the surgical approach in detail, with special emphasis on patient positioning for an orthogonal view, as well as technical nuances throughout the procedure. Using a sequential tubular retractor, they performed a microscopic dissection of the lesion. The tumor was debulked and the tumor capsule was disconnected from the surrounding tissue. During dissection, direct stimulation identified a functional nerve root that was carefully dissected from the tumor capsule. The tumor was then removed en bloc. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2220

Background Brain mapping is the most reliable intraoperative tool for identifying surrounding functional cortical and subcortical brain parenchyma. Brain mapping procedures are nuanced and require a multidisciplinary team and a well-trained neurosurgeon. Current training methodology involves real-time observation and operation, without widely available surgical simulation. Objective To develop a patient-specific, anatomically accurate, and electrically responsive biomimetic 3D-printed model for simulating brain mapping. Methods Imaging data were converted into a 2-piece inverse 3D-rendered polyvinyl acetate shell forming an anatomically accurate brain mold. Functional and diffusion tensor imaging data were used to guide wire placement to approximate the projection fibers from the arm and leg areas in the motor homunculus. Electrical parameters were generated, and data were collected and processed to differentiate between the 2 tracts. For validation, the relationship between the electrical signal and the distance between the probe and the tract was quantified. Neurosurgeons and trainees were interviewed to assess the validity of the model. Results Material testing of the brain component showed an elasticity modulus of 55 kPa (compared to 140 kPa of cadaveric brain), closely resembling the tactile feedback a live brain. The simulator's electrical properties approximated that of a live brain with a voltage-to-distance correlation coefficient of r2 = 0.86. Following 32 neurosurgeon interviews, ∼96% considered the model to be useful for training. Conclusion The realistic neural properties of the simulator greatly improve representation of a live surgical environment. This proof-of-concept model can be further developed to contain more complicated tractography, blood and cerebrospinal fluid circulation, and more in-depth feedback mechanisms.

BackgroundAlthough the liquid embolic agent, Onyx, is often the preferred embolic treatment for cerebral dural arteriovenous fistulas (DAVFs), there have only been a limited number of single-center studies to evaluate its performance.ObjectiveTo carry out a multicenter study to determine the predictors of complications, obliteration, and functional outcomes associated with primary Onyx embolization of DAVFs.MethodsFrom the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database, we identified patients who were treated for DAVF with Onyx-only embolization as the primary treatment between 2000 and 2013. Obliteration rate after initial embolization was determined based on the final angiographic run. Factors predictive of complete obliteration, complications, and functional independence were evaluated with multivariate logistic regression models.ResultsA total 146 patients with DAVFs were primarily embolized with Onyx. Mean follow-up was 29 months (range 0–129 months). Complete obliteration was achieved in 80 (55%) patients after initial embolization. Major cerebral complications occurred in six patients (4.1%). At last follow-up, 84% patients were functionally independent. Presence of flow symptoms, age over 65, presence of an occipital artery feeder, and preprocedural home anticoagulation use were predictive of non-obliteration. The transverse-sigmoid sinus junction location was associated with fewer complications, whereas the tentorial location was predictive of poor functional outcomes.ConclusionsIn this multicenter study, we report satisfactory performance of Onyx as a primary DAVF embolic agent. The tentorium remains a more challenging location for DAVF embolization, whereas DAVFs located at the transverse-sigmoid sinus junction are associated with fewer complications.

International audience; Abstract BACKGROUND Randomized controlled trials evaluating mechanical thrombectomy (MT) for acute ischemic stroke predominantly studied anterior circulation patients. Both procedural and clinical predictors of outcome in posterior circulation patients have not been evaluated in large cohort studies. OBJECTIVE To investigate technical and clinical predictors of functional independence after posterior circulation MT while comparing different frontline thrombectomy techniques. METHODS In a retrospective multicenter international study of 3045 patients undergoing MT for stroke between 06/2014 and 12/2018, 345 patients had posterior circulation strokes. MT was performed using aspiration, stent retriever, or combined approach. Functional outcomes were assessed using the 90-d modified Rankin score dichotomized into good (0-2) and poor outcomes (3-6). RESULTS We included 2700 patients with anterior circulation and 345 patients with posterior circulation strokes. Posterior patients (age: 60 ± 14, 46% females) presented with mainly basilar occlusion (80%) and were treated using contact aspiration or ADAPT (39%), stent retriever (31%) or combined approach (19%). Compared to anterior strokes, posterior strokes had delayed treatment (500 vs 340 min, P

OBJECTIVE The risk-to-benefit profile of treating an unruptured high-grade dural arteriovenous fistula (dAVF) is not clearly defined. The aim of this multicenter retrospective cohort study was to compare the outcomes of different interventions with observation for unruptured high-grade dAVFs. METHODS The authors retrospectively reviewed dAVF patients from 12 institutions participating in the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR). Patients with unruptured high-grade (Borden type II or III) dAVFs were included and categorized into four groups (observation, embolization, surgery, and stereotactic radiosurgery [SRS]) based on the initial management. The primary outcome was defined as the modified Rankin Scale (mRS) score at final follow-up. Secondary outcomes were good outcome (mRS scores 0–2) at final follow-up, symptomatic improvement, all-cause mortality, and dAVF obliteration. The outcomes of each intervention group were compared against those of the observation group as a reference, with adjustment for differences in baseline characteristics. RESULTS The study included 415 dAVF patients, accounting for 29, 324, 43, and 19 in the observation, embolization, surgery, and SRS groups, respectively. The mean radiological and clinical follow-up durations were 21 and 25 months, respectively. Functional outcomes were similar for embolization, surgery, and SRS compared with observation. With observation as a reference, obliteration rates were higher after embolization (adjusted OR [aOR] 7.147, p = 0.010) and surgery (aOR 33.803, p < 0.001) and all-cause mortality was lower after embolization (imputed, aOR 0.171, p = 0.040). Hemorrhage rates per 1000 patient-years were 101 for observation versus 9, 22, and 0 for embolization (p = 0.022), surgery (p = 0.245), and SRS (p = 0.077), respectively. Nonhemorrhagic neurological deficit rates were similar between each intervention group versus observation. CONCLUSIONS Embolization and surgery for unruptured high-grade dAVFs afforded a greater likelihood of obliteration than did observation. Embolization also reduced the risk of death and dAVF-associated hemorrhage compared with conservative management over a modest follow-up period. These findings support embolization as the first-line treatment of choice for appropriately selected unruptured Borden type II and III dAVFs.

BackgroundThe COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US.MethodsThe interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020.ResultsThere were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, PConclusionWe present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center.

Background and Purpose: Given the benign natural history of intracranial low-grade dural arteriovenous fistulas (dAVFs), their routine treatment remains controversial. The aim of this study is to compare the outcomes of low-grade dAVF treatment to conservative management. Methods: We performed a retrospective review of dAVF patients derived from 12 institutions participating in the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR). Patients with low-grade (Borden I) dAVFs were included and categorized into treatment and observation cohorts. Primary outcome was defined as modified Rankin Scale (mRS) score at final follow-up. Secondary outcomes were rates of excellent (mRS 0-1) and good (mRS 0-2) functional outcomes, symptomatic improvement, mortality, and obliteration at final follow-up. Results: The treatment and observation cohorts comprised 230 and 112 patients, respectively. At last follow up, no difference in primary or secondary outcomes was observed between the two cohorts, with the exception of obliteration, which was higher in the treatment cohort (79.3% vs. 28.2%, p Conclusions: Low-grade dAVF treatment was not associated with increased functional disability compared to conservative management. Although higher obliteration rates were achieved in the treatment cohort, rates of symptomatic improvement were similar between the two cohorts. This study did not provide evidence to support the routine treatment of low-grade dAVFs.

Once the accepted norm during Harvey Cushing's time, the mantra of work to the exclusion of family and lifestyle is now recognized as deleterious to overall well-being. A number of neurosurgical residency training programs have implemented wellness programs to enhance the physical, mental, and emotional well-being of trainees and faculty. This manuscript highlights existing organized wellness education within neurosurgery residency programs in order to describe the motivations behind development, structure, and potential implementation strategies, cost of implementation, and identify successes and barriers in the integration process. This manuscript is designed to serve as a "how-to" guide for other programs who may identify a need in their own trainees and begins the discussion of how to develop wellness, leadership, grit, and resiliency within our future generation of neurosurgeons.

Background: Inflammatory myofibroblastic tumor is a rare, poorly understood tumor that has been found to occur in almost every organ tissue. Its location within the central nervous system is uncommon, and patients tend to present with nonspecific symptoms. Case Description: A female in her eighth decade presented to neurosurgery clinic with complaints of headache and dizziness. Initial imaging was consistent with a low-grade, benign brain lesion in the region of the left choroidal fissure. She was recommended for observation but returned 1 month later with progressive symptoms and doubling of the lesion size. She underwent surgical resection and was found to have an IMT arising from the wall of the left anterior choroidal artery. Conclusion: Intracranial IMT remains a rare and poorly understood entity. The present case demonstrates a novel presentation of IMT in an adult patient and exemplifies the heterogeneity of the disease presentation.

STUDY DESIGN A retrospective national administrative database study. OBJECTIVE Advances in treatment of traumatic cervical spinal cord injury with fracture (TCSCIF) have led to significant improvements in clinical outcomes; however, progress in healthcare is seldom ubiquitous across demographic groups. Therefore, we explored if disparities in treatment and outcome after TCSCIF exist across race and socioeconomic status. SETTING USA. METHODS We queried the Nationwide Inpatient Sample database from 1998 to 2009 for TCSCIF hospitalizations. Multivariate analysis was used to identify the correlation between socioeconomic status and race to injury, treatment type, and outcome. RESULTS There were 21,985 admissions for TCSCIF, 66.9% of whom had a favorable discharge disposition. In-hospital mortality rate was 12.5%. A total of 43.7% underwent surgery. Overall, surgery was associated with lower in-hospital mortality (OR 0.30, 95% CI 0.27-0.34, p

OBJECTIVEInhibition of platelet aggregation is vital to preventing thromboembolic complications related to stent placement in endovascular neurosurgery, but excessive inhibition potentiates hemorrhagic complications. Recent evidence suggests an ideal inhibition range of 70–150 P2Y12 response units (PRU) as measured on the VerifyNow assay, which relies on photometric measurements of platelet aggregation. Thromboelastography (TEG) with platelet mapping (PM) is an alternative assay that directly measures clot formation and mechanical strength. This study compares the results of PRU to TEG-PM.METHODSPatients with simultaneous or near-simultaneous PRU and TEG-PM results who underwent cervical carotid artery stenting, intracranial stent-assisted aneurysm coiling, or flow diversion at the authors’ institution between August 2015 and November 2016 were identified. PRU results were compared with the TEG maximal amplitude (MA) attributable to adenosine diphosphate (ADP) activity (MA-ADP) as measured by TEG-PM. Platelet inhibition was considered therapeutic for MA-ADP values < 50 mm or PRU < 194. The Pearson correlation coefficient was calculated, and the sensitivity and specificity of PRU were calculated assuming that the results of TEG-PM reflected the true degree of platelet inhibition.RESULTSTwenty-three patients were identified with a total of 37 matched sets of TEG-PM and PRU. Three of these pairs were excluded due to anemia outside of the PRU manufacturer’s recommended range. The Pearson correlation coefficient for these values was 0.50 (p = 0.0026). The prevalence of clopidogrel nonresponders determined by TEG-PM (9%) matched reported rates (5%–12%); PRU demonstrated much higher prevalence (39%). For detecting a therapeutic level of platelet inhibition, PRU demonstrated a sensitivity of 0.59, specificity of 0.50, positive predictive value of 0.95, and negative predictive value of 0.07. Ideal inhibition was concordant in only 25% of observations in which at least one of the results was ideal.CONCLUSIONSAgreement between TEG-PM and PRU regarding the degree of platelet inhibition is poor. PRU likely overestimates clopidogrel resistance, as 93% of patients with PRU > 194 demonstrate a therapeutic level of platelet inhibition on TEG.

Military neurosurgery has played an integral role in the development and innovation of neurosurgery and neurocritical care in treating battlefield injuries. It is of paramount importance to continue to train and prepare the next generation of military neurosurgeons. For the Army, this is currently primarily achieved through the military neurosurgery residency at the National Capital Consortium and through full-time out-service positions at the Veterans Affairs–Department of Defense partnerships with the University of Florida, the University of Texas–San Antonio, and Baylor University. The authors describe the application process for military neurosurgery residency and highlight the training imparted to residents in a busy academic and level I trauma center at the University of Florida, with a focus on how case variety and volume at this particular civilian-partnered institution produces neurosurgeons who are prepared for the complexities of the battlefield. Further emphasis is also placed on collaboration for research as well as continuing education to maintain the skills of nondeployed neurosurgeons. With ongoing uncertainty regarding future conflict, it is critical to preserve and expand these civilian-military partnerships to maintain a standard level of readiness in order to face the unknown with the confidence befitting a military neurosurgeon.

We postulated that acute hypoxemia increases susceptibility to orthostatic hypotension by increasing the sensitivity of cardiovascular baroreceptors.Hemodynamics were measured noninvasively in 17 healthy, normotensive subjects while being subjected to decreasing venous return by exposure to lower body negative pressure (LBNP) and breathing either a normobaric normoxic (21% O2) or normobaric hypoxic (12% O2) gas mixture.Hypoxia variably decreased hemoglobin saturation (in percent+/-SEM, from 99%+/-1% to 87%+/-2%, P.01). Incremental increases in LBNP to -50 mm Hg significantly lowered systolic blood pressure (BP), pulse pressure (PP), forearm blood flow (FBF), and increased heart rate (HR). Hypoxia significantly increased baseline systolic BP, PP, and HR. The maximum change in HR in response to LBNP-induced reductions in PP increased during acute hypoxemia (maximum DeltaHR/DeltaPP, in +/-SEM) from 1.32+/-0.18 beats/min/mm Hg v 1.91+/-0.25 beats/min/mm Hg, P.05. Those subjects who had the most hemoglobin desaturation during hypoxia, when compared to those subjects who desaturated minimally, had greater systolic BP at rest (128+/-3 mm Hg v 114+/-3 mm Hg, P=.05) and during LBNP (115+/-4 mm Hg v 100+/-1 mm Hg, P=.01).Acute hypoxia increased compensatory HR responses to LBNP-dependent reductions in BP. Those normotensive individuals with higher BP at rest and during LBNP developed greater degrees of hypoxia-induced hemoglobin desaturation. Patients with sleep apnea with periods of hypoxemia are prone to hypertension; more important, patients with higher BPs also demonstrate greater degrees of hypoxia-induced desaturation of oxyhemoglobin.

A 33-year-old male presented for resection of an intracranial mass after 1 year of recurrent headaches and dizziness. Cerebrospinal fluid testing had shown a lymphocytic pleocytosis (163 cells/mm3, 59% lymphocytes, 20% neutrophils) with normal protein (42 mg/dL), glucose (54 mg/dL), cultures, and serologic testing. Multiple brain magnetic resonance imaging (MRI) studies showed enlarged ventricles but no masses. Immediately before surgery, a discrete cystic structure was visible on imaging (Figure 1 ). A large cyst consistent with neurocysticercosis was identified intraoperatively. No additional lesions were observed, and he had complete resolution of symptoms. He received 7 days of albendazole, dexamethasone, and levetiracetam per guidelines for a solitary lesion.1 Follow-up imaging using higher resolution (1 mm versus 6 mm planes) and volumetric sequencing displayed an extra-parenchymal cyst with a visible scolex lateral to the fourth ventricle (Figure 2 ). As a result of surgical excision, there was no evidence of a residual fourth ventricle cyst. His MRI spine was negative, and he received two additional months of therapy until radiographic resolution, per guidelines for extra-parenchymal lesions.1 This thin walled extra-parynchymal cyst was uncovered with higher quality imaging using both finer planes and an ultrafast MRI technique known as volumetric imaging (e.g., fast imaging employing steady-state acquisition [FIESTA] sequencing). Ideally, higher quality imaging would have revealed these cysts preoperatively. However, his films were suggestive of mass lesion and thus volumetric imaging was not performed until the surgical pathology provided a definitive diagnosis. This case displays the role that high quality volumetric imaging plays in the diagnosis of neurocysticercosis. Figure 1. (A) Gadolinium-enhanced magnetic resonance imaging (MRI) of the brain showing evidence of a fourth ventricular cystic structure. (B) Histopathology of a surgically removed cyst with i) cuticular layer with microvilli, ii) cellular layer, and iii) reticular ... Figure 2. Axial T2. Follow-up imaging 2 months post-surgical. (A) 1.2 cm cyst located at the right Foramen of Luschka (lateral recess of the fourth ventricle) consistent with neurocysticercosis cyst with internal scolex. (B) Post-surgical image displaying post-surgical ...