Transarterial Embolization of Intracranial Dural Arteriovenous Fistulas Cognard Type V With Direct Drainage Into the Perimedullary Veins: Case Report and Literature Review.

BACKGROUND AND IMPORTANCE: Cognard type V fistula (CVF) is a rare type of dural arteriovenous fistula characterized by spinal perimedullary venous drainage. Owing to the lack of pathognomonic findings, misdiagnosis is common. Patients often undergo multiple spinal angiograms negative for spinal vascular malformations. Digital subtraction angiography is the gold standard diagnostic tool. The preferred treatment option is endovascular management with embolization through a transarterial, transvenous, or combined approach. Other options include open surgery, stereotactic radiosurgery, or a combination of both. CLINICAL PRESENTATION: The patient from case # 1 presented with progressive weakness and hypoesthesia in the bilateral lower extremities, with urinary and bowel incontinence. The DSA identified a CVF fed by the meningohypophyseal trunk and a draining perimedullary vein. Embolization with 0.1 ccs of Onyx-18 was performed with complete fistula occlusion. The patient from case # 2 developed bilateral lower extremity weakness, diffuse numbness, and urinary incontinence. The DSA showed a CVF fed by tributaries from the ascending pharyngeal artery and posterior meningeal artery branches of the V3 segment, draining into a perimedullary vein. Embolization with 0.3 cc of Onyx-18 was performed with 100% occlusion of the fistula. A 1-year follow-up angiogram confirmed complete fistula occlusion. Both patients consented to the procedure. CONCLUSION: Even if a patient only presents symptoms of myelopathy, CVF should be considered. Herein, we present 2 cases of CVF with direct drainage into the perimedullary veins which presented exclusively with myelopathy syndrome and describe treatment with trasarterial embolization with Onyx.

Comparison between endovascular and surgical treatment of spinal dural arteriovenous fistulas: a single-center cohort and systematic review.

OBJECTIVE: With recent advancements in minimally invasive techniques, endovascular embolization has gained popularity as a first-line treatment option for spinal dural arteriovenous fistulas (sDAVFs). The authors present their institution's case series of sDAVFs treated endovascularly and surgically, and they performed a systemic review to assess the outcomes of both modalities of treatment. METHODS: The authors conducted a retrospective observational study of 24 consecutive patients with sDAVFs treated between 2013 and 2023. The primary outcome was the rate of occlusion, which was compared between the surgically and endovascularly treated sDAVFs. They also conducted a systemic review of all the literature comparing outcomes of endovascular and surgical treatment of sDAVFs. RESULTS: A total of 24 patients with 24 sDAVFs were studied. The mean patient age was 63.8 ± 15.5 years, and the majority of patients were male (n = 19, 79.2%). Of the 24 patients, 8 (33.3%) received endovascular treatment, 15 (62.5%) received surgical treatment, and 1 (4.2%) patient received both. Complete occlusion at first follow-up was higher in the surgical cohort but did not achieve statistical significance (66.7% vs 25%, p = 0.52). Recurrence was higher in the endovascular cohort (37.5% vs 13.3%, p = 0.3), while the rate of postprocedural complications was higher in the surgical cohort (13.3% vs 0%, p = 0.52); however, neither of these differences was statistically significant. CONCLUSIONS: Endovascular embolization in the management of sDAVFs is an alternative treatment to surgery, whose long-term efficacy is still under investigation. These findings suggest overall comparable outcomes between endovascular and open surgical treatment of sDAVFs. Future studies are needed to determine the role of endovascular embolization in the overall management of sDAVFs.

Middle Meningeal Artery Embolization for Subdural Hematoma: An Institutional Cohort and Propensity Score-Matched Comparison with Conventional Management.

BACKGROUND: The treatment of non-acute subdural hematoma (NASDH) is challenging due to its high recurrence rates and comorbidities of mostly elderly patients. Middle meningeal artery embolization (MMAE) recently emerged as an alternative to surgery in the treatment of NASDH. OBJECTIVE: To describe a single center's experience of MMAE with Onyx for NASDH and compare it to a surgically treated historical cohort. METHODS: We performed a retrospective analysis of patients undergoing MMAE for NASDH from 2019 to 2021. MMAE was performed with ethylene vinyl alcohol copolymer (Onyx). Comparisons were made with a historical cohort from 2010 to 2018 who underwent surgical evacuation only, before and after propensity score matching. Outcomes were assessed clinically and radiographically. RESULTS: We included 44 consecutive patients (55 MMAEs) who underwent MMAE, with a median follow-up of 63.5 days. Twenty-four NASDHs underwent upfront embolization, 17 adjunctive, and 14 for recurrence after prior surgical evacuation, with no significant differences in hematoma and mRS reduction between them. Two patients died during hospitalization and 2 during follow-up, unrelated to the procedure. Mean SDH thickness decreased by 48.3% ± 38.1% (P < 0.001) on last follow-up, which did not correlate with the amount of Onyx injected. Six (13.6%) patients required surgical rescue after embolization. There were no procedure-related complications. The mean modified Rankin Scale (mRS) on admission was 2.8 ± 1.5, which decreased significantly to 1 [1,4] at the last follow-up (P = 0.033). The MMAE (41 hematomas; upfront and adjunctive embolization) and Surgical Evacuation-only (461 hematomas) cohorts were balanced with propensity score mathing. Matching was successful for 41 MMAE and 41 surgical-only hematoma pairs, and only hypertension remained significantly different between the two groups, but there was no significant difference in any outcome. CONCLUSION: MMAE for NASDH seems safe and effective in appropriately selected patients, non-inferior to surgery, and may become a minimally-invasive alternative. Given our encouraging results, large-scale clinical randomized trials are warranted.

Ventriculostomy Associated with Reduced Mortality in Severe Traumatic Brain Injury Compared to Parenchymal ICP Monitoring: A Propensity Score-Adjusted Analysis.

BACKGROUND: There is a lack of data on whether intracranial pressure (ICP)-guided therapy with an intraparenchymal fiberoptic monitor (IPM) or an external ventricular drain (EVD) leads to superior outcomes. Our goal is to determine the relationship between ICP-guided therapy with an EVD or IPM and mortality. METHODS: Retrospective analysis of severe traumatic brain injury cases that required IPM or EVD placement for ICP-guided therapy from January 1, 2010 to December 31, 2020. The data were obtained from the Pennsylvania Trauma Systems Foundation registry. RESULTS: A total of 2305 patients met the inclusion criteria, with 1048 (45.5%) IPM and 1257 (54.5%) EVD placed. Inpatient mortality occurred in 337 (32.2%) and 334 (26.6%) patients in the IPM and EVD cohorts, respectively (P = 0.003). Even among those treated medically only, inpatient mortality occurred in 171 (30.8%) of those with an IPM and in 100 (23.4%) of those with an EVD (P = 0.010). Multivariable logistic regression analysis showed that older age (odds ratio [OR] 1.03, P < 0.001), lower Glasgow Coma Scale (GCS) score (OR 1.16, P < 0.001), requiring surgery (OR 1.22, P = 0.049), and an IPM (OR 1.40, P = 0.001) were significant predictors of mortality. Propensity score-adjusted analysis using inverse probability of treatment weighted method revealed a 28% decrease in mortality and a 14% decrease in length of hospital stay with EVD use when adjusting for age, sex, GCS, Injury Severity Score, surgery, and Hispanic ethnicity. CONCLUSIONS: A significant mortality benefit was associated with the use of EVD compared to IPM. This mortality benefit was observed regardless of whether patients required surgery or not.

Clinical Outcomes After Ultra-Early Cranioplasty Using Craniectomy Contour Classification as a Patient Selection Criterion.

BACKGROUND: Although not a technically difficult operation, cranioplasty is associated with high rates of complications. The optimal timing of cranioplasty to mitigate complications remains the subject of debate. OBJECTIVE: To report outcomes between patients undergoing cranioplasty at ultra-early (0-6 weeks), intermediate (6 weeks to 6 months), and late (>6 months) time frames. We report a novel craniectomy contour classification (CCC) as a radiographic parameter to assess readiness for cranioplasty. METHODS: A single-institution retrospective analysis of patients undergoing cranioplasty was performed. Patients were stratified into ultra-early (within 6 weeks of index craniectomy), intermediate (6 weeks to 6 months), and late (>6 months) cranioplasty cohorts. We have devised CCC scores, A, B, and C, based on radiographic criteria, where A represents those with a sunken brain/flap, B with a normal parenchymal contour, and C with "full" parenchyma. RESULTS: A total of 119 patients were included. There was no significant difference in postcranioplasty complications, including return to operating room ( P = .212), seizures ( P = .556), infection ( P = .140), need for shunting ( P = .204), and deep venous thrombosis ( P = .066), between the cohorts. Univariate logistic regression revealed that ultra-early cranioplasty was significantly associated with higher rate of functional independence at >6 months (odds ratio 4.32, 95% CI 1.39-15.13, P = .015) although this did not persist when adjusting for patient selection features (odds ratio 2.90, 95% CI 0.53-19.03, P = .234). CONCLUSION: In appropriately selected patients, ultra-early cranioplasty is not associated with increased rate of postoperative complications and is a viable option. The CCC may help guide decision-making on timing of cranioplasty.

Initial Heart Rate Predicts Functional Independence in Patients With Spinal Cord Injury Requiring Surgery: A Registry-Based Study in a Mature Trauma System Over the Past 10 Years.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To determine the ability of early vital sign abnormalities to predict functional independence in patients with SCI that required surgery. METHODS: A retrospective analysis of data extracted from the Pennsylvania Trauma Outcome Study database. Inclusion criteria were patients >18 years with a diagnosis of SCI who required urgent spine surgery in Pennsylvania from 1/1/2010-12/31/2020 and had complete records available. RESULTS: A total of 644 patients met the inclusion criteria. The mean age was 47.1 ± 14.9 years old and the mean injury severity score (ISS) was 22.3 ± 12.7 with the SCI occurring in the cervical, thoracic, and lumbar spine in 61.8%, 19.6% and 18.0%, respectively. Multivariable logistic regression analyses for predictors of functional independence at discharge showed that higher HR at the scene (OR 1.016, 95% CI 1.006-1.027, P = .002) and lower ISS score (OR .894, 95% CI .870-.920, P < .001) were significant predictors of functional independence. Similarly, higher admission HR (OR 1.015, 95% CI 1.004-1.027, P = .008) and lower ISS score (OR .880, 95% CI 0.864-.914, P < .001) were significant predictors of functional independence. Peak Youden indices showed that patients with HR at scene >70 and admission HR ≥83 were more likely to achieve functional independence. CONCLUSIONS: Early heart rate is a strong predictor of functional independence in patients with SCI. HR at scene >70 and admission HR ≥83 is associated with improved outcomes, suggesting lack of neurogenic shock.

Incidence of Pseudarthrosis and Subsequent Surgery After Cervical Fusion Surgery: A Retrospective Review of a National Health Care Claims Database.

BACKGROUND: Cervical pseudarthrosis is a postoperative adverse event that occurs when a surgically induced fusion fails to establish bone growth connecting the 2 regions. It has both clinical and financial implications and may result in significant patient morbidity; it continues to be one of the leading causes of pain after surgery. METHODS: A retrospective longitudinal cohort study was performed. Patients in the IBM MarketScan Commercial Claims and Encounters (CCAE) database, 18-64 years old, who underwent elective cervical fusions during 2015-2019 were included. Patients with trauma, infection, or neoplasm were excluded. Patients were followed for 2 years from surgical fusion for occurrence of pseudarthrosis. After pseudarthrosis, subsequent surgery was documented, and cumulative incidence curves, adjusted for patient/procedure characteristics, with 95% confidence intervals (CIs) were generated. Risk factors were evaluated with multivariable Cox regression analysis. RESULTS: The cohort included 45,584 patients. The 1-year and 2-year incidence of pseudarthrosis was 2.0% (95% CI, 1.9%-2.2%) and 3.3% (95% CI, 3.1%-3.5%), respectively. Factors significantly associated with increased risk of pseudarthrosis were female gender, current/previous substance abuse, previous spinal pain in the cervical/thoracic/lumbar spine, and Elixhauser score ≥5. Factors significantly associated with decreased risk of pseudarthrosis were anterior cervical approach, use of an interbody cage, and 2-level or 3-level anterior instrumentation. The 1-year and 2-year incidence of subsequent surgery in patients with pseudarthrosis was 11.7% (95% CI, 9.6%-13.7%) and 13.8% (95% CI, 11.5%-16.2%), respectively. CONCLUSIONS: Cervical pseudarthrosis and subsequent surgery still occur at a low rate. Surgical factors such as anterior approach, interbody cage use, and anterior instrumentation may reduce pseudarthrosis risk.

The use of telemedicine in pre-surgical evaluation: a retrospective cohort study of a neurosurgical oncology practice.

PURPOSE: To determine if there was a discrepancy between telemedicine versus in-person New Patient Visits (NPVs) regarding the conversion rate to operative and radiosurgery cases at a tertiary surgical neuro-oncology practice. METHODS: A retrospective analysis was performed of patients who had an outpatient encounter with a neurosurgeon from the Tumor Division at our institution's Department of Neurosurgery between February 1, 2021 and April 30, 2021. NPVs during this period were registered as either telemedicine or in-person appointments. The primary endpoint of the study was to compare the rate at which telemedicine NPVs and in-person NPVs underwent surgery or radiosurgery, reported as the surgical conversion rate. RESULTS: A total of 206 patients were included in this study. Of them, 119 (57.8%) were seen using telemedicine and 87 (42.2%) were seen in clinic via an in-person visit. A total of 70 (34%) of all patients underwent surgery or radiosurgery. Of the 119 patients seen via telemedicine, 40 (33.6%) underwent surgery or radiosurgery; during the same period, 87 NPVs were conducted in person and 30 (34.5%, p = 1.0) received an intervention. Further stratification revealed no differences between the two groups across measured criteria including diagnosis, number of pre-operative visits, elapsed time from appointment to surgery, follow-up visits, and distance from home address to neurosurgical clinic. CONCLUSION: Telemedicine NPVs did not differ significantly from in-person NPVs when evaluating the likelihood of a new patient committing to surgical treatment. This study provides quantifiable evidence that telemedicine is an effective means of meeting new patients and planning complex neurosurgical interventions.

Radiation of meningioma dural tail may not improve tumor control rates.

Introduction: Dural tails are thickened contrast-enhancing portions of dura associated with some meningiomas. Prior studies have demonstrated the presence of tumor cells within the dural tail, however their inclusion in radiation treatment fields remains controversial. We evaluated the role of including the dural tail when treating a meningioma with stereotactic radiation and the impact on tumor recurrence. Methods: This is a retrospective, single-institution, cohort study of patients with intracranial World Health Organization (WHO) grade 1 meningioma and identified dural tail who were treated with stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) from January 2012 to December 2018. SRS and FSRT subgroups were categorized based on coverage or non-coverage of the dural tail by the radiation fields, as determined independently by a radiation oncologist and a neurosurgeon. Demographics, tumor characteristics, radiation plans, and outcomes were evaluated. High grade tumors were analyzed separately. Results: A total of 187 WHO grade 1 tumors from 177 patients were included in the study (median age: 62 years, median follow-up: 40 months, 78.1% female) with 104 receiving SRS and 83 receiving FSRT. The dural tail was covered in 141 (75.4%) of treatment plans. There was no difference in recurrence rates (RR) or time to recurrence (TTR) between non-coverage or coverage of dural tails (RR: 2.2% vs 3.5%, P = 1.0; TTR: 34 vs 36 months, P = 1.00). There was no difference in the rate of radiation side effects between dural tail coverage or non-coverage groups. These associations remained stable when SRS and FSRT subgroups were considered separately, as well as in a high grade cohort of 16 tumors. Conclusion: Inclusion of the dural tail in the SRS or FSRT volumes for meningioma treatment does not seem to reduce recurrence rate. Improved understanding of dural tail pathophysiology, tumor grade, tumor spread, and radiation response is needed to better predict the response of meningiomas to radiotherapy.

Frameless Angiography-Based Gamma Knife Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations: A Proof-of-Concept Study.

BACKGROUND: Traditional Gamma Knife radiosurgery (GKRS) of brain arteriovenous malformations (AVMs) using digital subtraction angiography (DSA) requires head immobilization using a stereotactic frame. OBJECTIVE: We describe our protocol of frameless GKRS using DSA while maintaining high spatial resolution for precision. METHODS: This study is a retrospective review of patients with unruptured AVMs who underwent frameless GKRS. Magnetic resonance imaging and 3-dimensional DSA were obtained without a stereotactic frame for all patients. The imaging studies were merged for contouring of the AVM nidus. During GKRS treatment, patients were immobilized using an individually molded thermoplastic mask. RESULTS: Thirty-one patients were included in the analysis. The median age is 45.0 years (interquartile range [IQR]: 28.0-55.0). The median nidus size is 3.0 cm (IQR: 2.0-3.4). One patient had a Spetzler-Martin grade I, 11 had a grade II, 11 had a grade III, 6 had a grade IV, and 2 had a grade V AVM. Eleven patients underwent preradiosurgical embolization, 3 patients had previous microsurgical resection and/or embolization, and 1 patient had prior radiosurgery. The median administered dose was 20 Gy (IQR: 18.0-21.0). All patients completed their treatment with the planned radiation dose without complications. CONCLUSION: This is the first study that integrates DSA in the treatment planning of brain AVMs using GKRS without utilizing a stereotactic head frame. Frameless GKRS provides numerous advantages over frame-based techniques including improved patient experience and the capability of fractionation and thus expanding the eligibility of more AVMs for radiosurgery, while maintaining high spatial resolution of the AVM using angiography data.

A review of multiomics platforms in pituitary adenoma pathogenesis.

Pituitary adenomas (PA), or pituitary neuroendocrine tumors (PitNETs), represent 15% of all central nervous system tumors. Classic description of PitNETs solely by hormonal classification has given way to key transcription factors that play a role in the pathology of PitNETs including steroidogenic factor-1 (SF-1), t-box pituitary transcription factor (TPIT), and pituitary transcription factor 1 (PIT-1). Germline mutations in various familial PitNETs are discussed including those in familial isolated pituitary adenoma (FIPA), multiple endocrine neoplasia (MEN), neurofibromatosis 1 (NF1), and Carney complex. Recent advances in next generation sequencing have improved insight into the pathogenesis of PitNETs. A review of key studies in evaluating the genomic analysis of PitNETs was performed. Chromosomal mutations, whole exome sequencing, microRNA genomics, methylomics and transcriptomics were analyzed. Moreover, the multiomic analysis of various genomic panels has helped to better understand PA classification.

Telemedicine in Neurosurgery During the COVID-19 Outbreak: Where We Are 1 Year Later.

BACKGROUND: Telemedicine use skyrocketed in March 2020 on implementation of shelter-in-place measures owing to the coronavirus disease 2019 (COVID-19) pandemic. Within the past year, shelter-in-place measures were lifted and the COVID-19 vaccine was released, resulting in many neurosurgeons returning to in-person outpatient clinics. This study aimed to determine the extent of usage of telemedicine in neurosurgery 1 year into the COVID-19 pandemic. METHODS: A retrospective cohort study of patients who received neurosurgical care at a single institution from February 1 to April 18 of the years 2020 and 2021 was performed. The inclusion criteria were met by 11,592 patients. During the 2 study periods, 1465 patients underwent surgery, 7083 were seen in clinic via an in-person meeting, and 3044 were assessed via telemedicine. RESULTS: At 1 year after the COVID-19 outbreak, telemedicine usage was at 81.3% of the initial volume on implementation of shelter-in-place measures. In-person outpatient visits increased 40.2% from the early pandemic volume. Among the 4 neurosurgery divisions, telemedicine usage remained high in tumor and functional neurosurgery, significantly increased in vascular neurosurgery, and decreased in spine neurosurgery. CONCLUSIONS: Telemedicine use in neurosurgery clinics continues 1 year after the COVID-19 outbreak. Even after the lifting of shelter-in-place measures, many neurosurgeons still use telemedicine, while the operative volume remains stable. Owing to the limited physical examination that can be performed via current telemedicine platforms, telemedicine use in spine neurosurgery is lower than peak use during the early pandemic, while use has remained high among tumor, vascular, and functional neurosurgery.

A Review of Endoscopic Spine Surgery: Decompression for Radiculopathy.

PURPOSE OF REVIEW: With this manuscript the authors sought to write a succinct review of the origins, as well as the latest advancements in endoscopic spine surgery to serve as a reference frame for physicians looking to learn this approach. RECENT FINDINGS: At its infancy, the indications for posterolateral and transforaminal endoscopic decompression remained narrow, which prevented the procedure from gaining rapid traction during those days. However, more recently the tides have turned and an increasing number of surgeons are starting to adopt this technique given all its advantages. With the advent of higher quality camera systems and instruments, indications to use a minimally invasive option have gotten significantly broader. The most basic indication for the use of this technology is a soft disc herniation causing compromise of a neural structure that has failed to be managed successfully with non-surgical therapies. The use of endoscopic techniques provides significant advantages to patient outcomes and patient recovery. Endoscopic procedures should not be used as a blanket approach to nerve root decompression, as they certainly have limitations. Most contraindications to this procedure are relative and serve mostly as points to consider when selecting the methods to address neural compression. As these techniques become more widely accepted, we expect its reach and indications to continue to broaden and diversify. The full integration of navigation technologies will likely leapfrog this procedure into the mainstream use.

Predictors of aneurysm occlusion following treatment with the WEB device: systematic review and case series.

The Woven EndoBridge (WEB) device is becoming increasingly popular for treatment of wide-neck aneurysms. As experience with this device grows, it is important to identify factors associated with occlusion following WEB treatment to guide decision making and screen patients at high risk for recurrence. The aim of this study was to identify factors associated with adequate aneurysm occlusion following WEB device treatment in the neurosurgical literature and in our case series. A systematic review of the present literature was conducted to identify studies related to the prediction of WEB device occlusion. In addition, a retrospective review of our institutional data for patients treated with the WEB device was performed. Demographics, aneurysm characteristics, procedural variables, and 6-month follow-up angiographic outcomes were recorded. Seven articles totaling 450 patients with 456 aneurysms fit our criteria. Factors in the literature associated with inadequate occlusion included larger size, increased neck width, partial intrasaccular thrombosis, irregular shape, and tobacco use. Our retrospective review identified 43 patients with 45 aneurysms. A total of 91.1% of our patients achieved adequate occlusion at a mean follow-up time of 7.32 months. Increasing degree of contrast stasis after WEB placement on the post-deployment angiogram was significantly associated with adequate occlusion on follow-up angiogram (p = 0.005) and with Raymond-Roy classification (p = 0.048), but not with retreatment (p = 0.617). In our systematic review and case series totaling 450 patients with 456 aneurysms, contrast stasis on post-deployment angiogram was identified as a predictor of adequate aneurysm occlusion, while morphological characteristics such as larger size and wide neck negatively impact occlusion.

Decompressive Hemicraniectomy in the Modern Era of Mechanical Thrombectomy.

OBJECTIVES: We aim to determine the incidence of decompressive hemicraniectomy (DHC) in the modern era of mechanical thrombectomy techniques and improved revascularization outcomes. METHODS: We performed a retrospective analysis of 512 patients admitted with acute ischemic strokes with anterior circulation large-vessel occlusion that were treated by mechanical thrombectomy from 2010-2019. The primary endpoint was the need for surgical decompression. Secondary endpoints were infarct size, hemorrhagic conversion, and functional outcome at hospital discharge. RESULTS: Of the 512 patients, 18 (3.5%) underwent DHC at a median 2.0 days from stroke onset. The DHC group was significantly younger than the non-DHC group (P < 0.001), had worse reperfusion rates (P = 0.024) and larger infarct size (P < 0.001). Hemorrhagic conversion was more frequent in the DHC group but did not reach statistical significance (P = 0.08). From 2010-2015, 196 patients underwent a mechanical thrombectomy, 13 of whom (6.6%) required a DHC, while 316 patients underwent mechanical thrombectomy from 2016-2019 and only 5 patients required a DHC (1.6%; P = 0.002). Younger age (P < 0.001), urinary tract infection (P < 0.001) and increasing infarct size were significantly associated with needing a DHC. When controlling for other risk factors, higher thrombolysis in cerebral infarction score significantly reduced the need for decompressive hemicraniectomy (P = 0.004). CONCLUSIONS: This is one of the largest single-center experiences demonstrating that improved recanalization decreased the need for DHC without increasing the risk of hemorrhagic conversion.

The Impact of Incorporating Evidence-Based Guidelines for Lumbar Fusion Surgery in Neurosurgical Resident Education.

BACKGROUND: Instrumented fusion procedures are essential in the treatment of degenerative lumbar spine disease to alleviate pain and improve neurological function, but they are being performed with increasing incidence and variability. We implemented a training module for neurosurgery residents that is based on evidence-based criteria for lumbar fusion surgery and measured its effectiveness in residents' decision making regarding whether patients should or should not undergo instrumented fusion. METHODS: The study design was a pretest versus posttest experiment conducted from September 2019 until July 2020 to measure improvement after formalized instruction on evidence-based guidelines. Neurosurgery residents of all training levels at our institution participated. A test was administered at the beginning of each academic year. The highest possible score was 18 points in each pretest and posttest. RESULTS: There was a general trend of test score improvement across all levels of training with a greater degree of change for participants with lower compared with higher pretest scores, indicating a possible ceiling effect. Paired t test demonstrated an overall mean score increase of 2 points (P < 0.0001), equivalent to an 11.11% increase (P < 0.0001). Stratified by training group, mean absolute change in test score was 2 (P = 0.0217), 1.67 (P = 0.0108), and 2.25 (P = 0.0173) points for junior, midlevel, and senior training groups, respectively. CONCLUSIONS: Incorporating a targeted evidence-based learning module for lumbar spine fusion surgery can improve neurosurgery residents' clinical decision making toward a more uniform practice supported by published data.

Bundled Payment Models in Spine Surgery.

STUDY DESIGN: The following is a narrative discussion of bundled payments in spine surgery. OBJECTIVE: The cost of healthcare in the United States has continued to increase. To lower the cost of healthcare, reimbursement models are being investigated as potential cost saving interventions by driving incentives and quality improvement in fields such a spine surgery. METHODS: Narrative overview of literature pertaining to bundled payments in spine surgery synthesizing findings from computerized databases and authoritative texts. RESULTS: Spine surgery is challenging to define payment modes because of high cost variability and surgical decision-making nuances. While implementing bundled care payments in spine surgery, it is important to understand concepts such as value-based purchasing, episodes of care, prospective versus retrospective payment models, one versus two-sided risk, risk adjustment, and outlier protection. Strategies for implementation underscore the importance of risk stratification and modeling, adoption of evidence based clinical pathways, and data collection and dissemination. While bundled care models have been successfully implemented, challenges facing institutions adopting bundled care payment models include financial stressors during adoption of the model, distribution of risks, incentivization of treating only low risk patients, and nuanced variation in procedures leading to variation in costs. CONCLUSION: An alternative for fee for service payments, bundled care payments may lead to higher cost savings and surgeon accountability in a patient's care.

Prediction of hematoma expansion in spontaneous intracerebral hemorrhage: Our institutional experience.

BACKGROUND: Spontaneous intracerebral hemorrhage (sICH) is a disease process with high morbidity and mortality. In particular, hematoma expansion (HE) is a feared complication of sICH. With 15-40% of patients experiencing HE, it has become increasingly important to predict which sICH will remain stable and which will expand. OBJECTIVE: With new treatment options being developed, it is becoming increasingly important to be able to predict which hemorrhages are at high versus low risk for expansion. The authors of this study hope to reexamine variables associated with hematoma expansion in hopes of generating newer data on risk factors for expansion. METHODS: A retrospective analysis identified 334 patients who presented with sICH. The primary outcome was HE on follow up head CT. HE was defined as a greater than 33% increase or an absolute increase in 6 mL or more in overall volume between the two sets of CT images. Analysis was performed using unpaired t-test, Chi-square, and Fisher's exact tests, as appropriate. RESULTS: Of the 334 patients, 247 (74.0%) did not experience an expansion of their ICH while 87 (26.0%) did. Multivariable logistic regression was performed demonstrating ICH score of 3 or greater (4.76 (95% CI 2.60-8.72, p < 0.001) , cortical location of the sICH (1.77 (95% CI 1.03-3.04, p = 0.038), and presence of a fluid level (6.46 (95% CI 2.28-18.3, p < 0.001) as significant predictors of HE. CONCLUSIONS: Our study found that fluid-fluid levels on non-contrast CT, an ICH score 3 or greater, and lobar sICH were all more likely to expand.

Comparison of Transradial vs Transfemoral Access in Neurovascular Fellowship Training: Overcoming the Learning Curve.

BACKGROUND: The transradial access (TRA) is rapidly gaining popularity for neuroendovascular procedures as there is strong evidence for its benefits compared to the traditional transfemoral access (TFA). However, the transition to TRA bears some challenges including optimization of the interventional suite set-up and workflow as well as its impact on fellowship training. OBJECTIVE: To compare the learning curves of TFA and TRA for diagnostic cerebral angiograms in neuroendovascular fellowship training. METHODS: We prospectively collected diagnostic angiogram procedural data on the performance of 2 neuroendovascular fellows with no prior endovascular experience who trained at our institution from July 2018 until June 2019. Metrics for operator proficiency were minutes of fluoroscopy time, procedure time, and volume of contrast used. RESULTS: A total of 293 diagnostic angiograms were included in the analysis. Of those, 57.7% were TRA and 42.3% were TFA. The median contrast dose was 60 cc, and the median radiation dose was 14 000 µGy. The overall complication rate was 1.4% consisting of 2 groin hematomas, 1 wrist hematoma, and 1 access-site infection using TFA. The crossover rate to TFA was 2.1%. Proficiency was achieved after 60 femoral and 95 radial cases based on fluoroscopy time, 52 femoral and 77 radial cases based on procedure time, and 53 femoral and 64 radial cases based on contrast volume. CONCLUSION: Our study demonstrates that the use of TRA can be safely incorporated into neuroendovascular training without causing an increase in complications or significantly prolonging procedure time or contrast use.