Short- and Long-Term MRI Assessed Hemodynamic Changes in Pediatric Moyamoya Patients After Revascularization.

BACKGROUND: Cerebrovascular reserve (CVR) reflects the capacity of cerebral blood flow (CBF) to change following a vasodilation challenge. Decreased CVR is associated with a higher stroke risk in patients with cerebrovascular diseases. While revascularization can improve CVR and reduce this risk in adult patients with vasculopathy such as those with Moyamoya disease, its impact on hemodynamics in pediatric patients remains to be elucidated. Arterial spin labeling (ASL) is a quantitative MRI technique that can measure CBF, CVR, and arterial transit time (ATT) non-invasively. PURPOSE: To investigate the short- and long-term changes in hemodynamics after bypass surgeries in patients with Moyamoya disease. STUDY TYPE: Longitudinal. POPULATION: Forty-six patients (11 months-18 years, 28 females) with Moyamoya disease. FIELD STRENGTH/SEQUENCE: 3-T, single- and multi-delay ASL, T1-weighted, T2-FLAIR, 3D MRA. ASSESSMENT: Imaging was performed 2 weeks before and 1 week and 6 months after surgical intervention. Acetazolamide was employed to induce vasodilation during the imaging procedure. CBF and ATT were measured by fitting the ASL data to the general kinetic model. CVR was computed as the percentage change in CBF. The mean CBF, ATT, and CVR values were measured in the regions affected by vasculopathy. STATISTICAL TESTS: Pre- and post-revascularization CVR, CBF, and ATT were compared for different regions of the brain. P-values <0.05 were considered statistically significant. RESULTS: ASL-derived CBF in flow territories affected by vasculopathy significantly increased after bypass by 41 ± 31% within a week. At 6 months, CBF significantly increased by 51 ± 34%, CVR increased by 68 ± 33%, and ATT was significantly reduced by 6.6 ± 2.9%. DATA CONCLUSION: There may be short- and long-term improvement in the hemodynamic parameters of pediatric Moyamoya patients after bypass surgery. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.

Single-step growth of graphene and graphene-based nanostructures by plasma-enhanced chemical vapor deposition.

The realization of many promising technological applications of graphene and graphene-based nanostructures depends on the availability of reliable, scalable, high-yield and low-cost synthesis methods. Plasma enhanced chemical vapor deposition (PECVD) has been a versatile technique for synthesizing many carbon-based materials, because PECVD provides a rich chemical environment, including a mixture of radicals, molecules and ions from hydrocarbon precursors, which enables graphene growth on a variety of material surfaces at lower temperatures and faster growth than typical thermal chemical vapor deposition. Here we review recent advances in the PECVD techniques for synthesis of various graphene and graphene-based nanostructures, including horizontal growth of monolayer and multilayer graphene sheets, vertical growth of graphene nanostructures such as graphene nanostripes with large aspect ratios, direct and selective deposition of monolayer and multi-layer graphene on nanostructured substrates, and growth of multi-wall carbon nanotubes. By properly controlling the gas environment of the plasma, it is found that no active heating is necessary for the PECVD growth processes, and that high-yield growth can take place in a single step on a variety of surfaces, including metallic, semiconducting and insulating materials. Phenomenological understanding of the growth mechanisms are described. Finally, challenges and promising outlook for further development in the PECVD techniques for graphene-based applications are discussed.

Surgical treatment of brain arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia: a single-center experience.

OBJECTIVE: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal-dominant disorder characterized by multiple vascular malformations. Brain arteriovenous malformations (bAVMs) are a significant manifestation of HHT. The surgical management of these lesions in patients with HHT remains debated, with limited literature on postoperative outcomes. The goal of this study was to evaluate the safety and efficacy of surgical treatment for bAVMs in patients with HHT and propose a treatment rationale based on a single-center experience. METHODS: This retrospective review included 20 patients diagnosed with HHT who underwent resection of 23 bAVMs at the Stanford University Medical Center between January 2007 and September 2023. Data were also collected on bAVMs treated conservatively, with embolization, or with radiosurgery at the authors' institution, for comparison. RESULTS: There were 16 Spetzler-Martin (SM) grade I, 6 SM grade II, and 1 SM grade IV bAVM. Six of the bAVMs presented with neurological symptoms (3 with hemorrhage and 3 with focal neurological deficits), while the rest were detected on routine screening. Complete excision was angiographically confirmed in all patients, with a mean overall hospital stay of 2.1 days and a mean follow-up of 36 months. Postoperative complications were limited to transient mild weakness in 2 patients, 1 of whom also had transient speech deficits, and visual field deficits in 3 patients, 2 of whom improved on long-term follow-up. CONCLUSIONS: In this most extensive surgical series published to date, resection of bAVMs in patients with HHT showed favorable outcomes with a low complication rate, suggesting that the benefits of surgery outweigh the risks, especially considering the potential cumulative lifetime risk of hemorrhage. MR arterial spin labeling was found to be the most sensitive noninvasive measure of detecting bAVMs in patients with HHT.

Improved survival in the largest national cohort of adults with cerebellar versus supratentorial low-grade astrocytomas.

OBJECT: Low-grade gliomas (LGGs) are indolent tumors that have the potential to dedifferentiate into malignant high-grade tumors. Recent studies have demonstrated that cerebellar low-grade tumors have a better prognosis than supratentorial tumors, although no study has focused on the risk factors for poor prognosis in cerebellar LGGs in adults. The authors of the current study aimed to address both of these concerns by using a large cohort derived from a national cancer registry and a smaller cohort derived from their institution's experience. METHODS: Adults with diagnosed Grade I and Grade II gliomas of the cerebellum were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate Cox proportional hazard models were used to predict rates of survival, and the log-rank test was applied to evaluate differences in Kaplan-Meier survival curves. An institutional cohort was created by isolating all patients whose surgical pathology revealed an LGG of the cerebellum. Excluded from analysis were patients in whom a glioma was first diagnosed under the age of 18 years and those whose tumors could not be definitively determined to arise from the cerebellum. Results Data from the local cohort (11 patients) demonstrated that the most common presenting symptom was headache, which occurred in more than 70% of the cohort. Approximately half of the patients in this cohort had symptomatic improvement after treatment. RESULTS: from the SEER cohort (166 patients) revealed that adults with Grade I gliomas were slightly younger than those with Grade II tumors (p < 0.01), but no other demographic differences were observed. Patients with Grade I tumors were twice as likely to undergo gross-total resection (54% vs 21%), and those with Grade II gliomas were much more likely to receive postoperative radiation (3% vs 48%). Five-year survival was greater in the patients with Grade I gliomas than in those with Grade II lesions (91% vs 70%). Multivariate analysis revealed that an age ≥ 40 years (HR 7.30, 95% CI 3.55-15.0, p < 0.0001) and Grade II tumors (HR 2.76, 95% CI 1.12-6.84, p = 0.028) were risk factors for death, whereas female sex was protective (HR 0.28, 95% CI 0.14-0.59, p < 0.001). Log-rank tests revealed that a cerebellar location was protective (p < 0.0001), but this relationship was only true for Grade II tumors (p < 0.0001). Survival in patients with Grade I gliomas was not different based on the various lesion locations (p = 0.21). CONCLUSIONS: Taken together, adults with cerebellar WHO Grade I and II astrocytomas have a much more favorable survival curve than those with similar supratentorial tumors. Research demonstrates that the primary driver of this phenomenon is the improved survival in patients with cerebellar Grade II gliomas.

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.

Thrombin and hemin as central factors in the mechanisms of intracerebral hemorrhage-induced secondary brain injury and as potential targets for intervention.

Intracerebral hemorrhage (ICH) is a subtype of stoke that may cause significant morbidity and mortality. Brain injury due to ICH initially occurs within the first few hours as a result of mass effect due to hematoma formation. However, there is increasing interest in the mechanisms of secondary brain injury as many patients continue to deteriorate clinically despite no signs of rehemorrhage or hematoma expansion. This continued insult after primary hemorrhage is believed to be mediated by the cytotoxic, excitotoxic, oxidative, and inflammatory effects of intraparenchymal blood. The main factors responsible for this injury are thrombin and erythrocyte contents such as hemoglobin. Therapies including thrombin inhibitors, N-methyl-D-aspartate antagonists, chelators to bind free iron, and antiinflammatory drugs are currently under investigation for reducing this secondary brain injury. This review will discuss the molecular mechanisms of brain injury as a result of intraparenchymal blood, potential targets for therapeutic intervention, and treatment strategies currently in development.

Significant Capacitance Enhancement via In Situ Exfoliation of Quasi-One-Dimensional Graphene Nanostripes in Supercapacitor Electrodes.

Graphene has received much attention as a supercapacitor electrode material due to its chemical inertness in preventing reaction with electrolytes and the large surface area due to its two-dimensional nature. However, when graphene sheets are processed into electrodes, they tend to stack together and form a turbostratic graphite material with a much reduced surface area relative to the total surface area of individual graphene sheets. Separately, electrochemical exfoliation of graphite is one method of producing single-layer graphene, which is often used to produce graphene for supercapacitor electrodes, although such exfoliated graphene still leads to reduced surface areas due to stacking during electrode fabrication. To utilize the large surface area of graphene, graphene must be exfoliated in situ within a supercapacitor device after the device fabrication. However, graphitic electrodes are typically destroyed upon exfoliation, which is largely due to the loss of electrical connectivity among small exfoliated graphene flakes. Here, we report successful in situ exfoliation of graphene nanostripes, a type of quasi-one-dimensional graphene nanomaterial with large length-to-width aspect ratios, as the anode material in supercapacitors. We find that the in situ exfoliation leads to over 400% enhancement in capacitance as the result of retaining the electrical connectivity among exfoliated quasi-one-dimensional graphene nanostripes in addition to increasing the total surface area, paving ways to fully realizing the benefit of graphene electrodes in supercapacitor applications.

Regression of Multiple Meningiomas after Discontinuation of Chronic Hormone Therapy: A Case Report.

Introduction Meningiomas are more common in females and frequently express progesterone and estrogen receptors. Recent studies have revealed a high incidence of meningiomas in situations in which estrogen/progesterone levels are increased such as pregnancy, gender reassignment therapy, and fertility treatment. While the relationship remains unclear and controversial, these findings suggest exposure to high levels of endogenous or exogenous hormones may increase the risk of developing a meningioma. Patients and Methods A 40-year-old female with a history of endometriosis treated with chronic progesterone therapy presented with a visual deficit and was found to have multiple meningiomas, which regressed after cessation of exogenous progesterone. Conclusion A history of chronic hormone therapy should be included when evaluating patients diagnosed with meningiomas, particularly at a younger age and with multiple meningiomas. Cessation of exogenous progesterone resulting in regression of meningiomas suggests a direct action of progesterone on growth. Future studies are warranted to better elucidate this relationship.

Carotid Revascularization: Current Practice and Future Directions.

Carotid stenosis is responsible for approximately 15% of ischemic strokes. Carotid revascularization significantly decreases patients' stroke risk. Carotid endarterectomy has first-line therapy for moderate-to-severe carotid stenosis after a series of pivotal randomized controlled trials were published almost 30 years ago. Revascularization with carotid stenting has become a popular and effective alternative in a select subpopulation of patients. We review the current state of the literature regarding revascularization indications, patient selection, advantages of each revascularization approach, timing of intervention, and emerging interventional techniques, such as transcarotid artery revascularization.

Selective formation of pyridinic-type nitrogen-doped graphene and its application in lithium-ion battery anodes.

We report a high-yield single-step method for synthesizing nitrogen-doped graphene nanostripes (N-GNSPs) with an unprecedentedly high percentage of pyridinic-type doping (>86% of the nitrogen sites), and investigate the performance of the resulting N-GNSPs as a lithium-ion battery (LIB) anode material. The as-grown N-GNSPs are compared with undoped GNSPs using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), helium ion-beam microscopy (HIM), and electrochemical methods. As an anode material we find that pyridinic-type N-GNSPs perform similarly to undoped GNSPs, suggesting that pyridinic sites alone are not responsible for the enhanced performance of nitrogen-doped graphene observed in previous studies, which contradicts common conjectures. In addition, post-mortem XPS measurements of nitrogen-doped graphene cycled as a lithium-ion battery anode are conducted for the first time, which reveal direct evidence for irreversible chemical changes at the nitrogen sites during cycling. These findings therefore provide new insights into the mechanistic models of doped graphene as LIB anodes, which are important in improving the anode designs for better LIB performance.

Arachnoiditis ossificans of the thoracic spine.

Arachnoiditis ossificans is a rare disorder characterized by the development of calcifications of the arachnoid membrane of the thoracic and lumbar spines. It is an extremely rare cause of spinal canal stenosis and consequent neurological compromise, and its origins and optimal management remain unclear. We review of the literature that illustrates the challenges of diagnosis and treatment of arachnoiditis ossificans. A patient with arachnoiditis ossificans is discussed to illustrate the presentation, treatment, and prognosis of the disease.

Giant, completely calcified lumbar juxtafacet cyst: report of an unusual case.

Study Design Case report. Objective To report the case of one patient who developed a giant, completely calcified, juxtafacet cyst. Methods A 57-year-old woman presented with a 2-year history of progressively worsening lower back pain, left leg pain, weakness, and paresthesias. Imaging showed a giant, completely calcified mass arising from the left L5-S1 facet joint, with coexisting grade I L5 on S1 anterolisthesis. The patient was treated with laminectomy, excision of the mass, and L5-S1 fixation and fusion. Results The patient had an uncomplicated postoperative course and had complete resolution of her symptoms as of 1-year follow-up. Conclusions When presented with a solid-appearing, calcified mass arising from the facet joint, a completely calcified juxtafacet cyst should be considered as part of the differential diagnosis.

Utilization of spinal cord stimulation in patients with failed back surgery syndrome.

STUDY DESIGN: Retrospective analysis of a population-based insurance claims data set. OBJECTIVE: To evaluate the use of spinal cord stimulation (SCS) and lumbar reoperation for the treatment of failed back surgery syndrome (FBSS), and examine their associated complications and health care costs. SUMMARY OF BACKGROUND DATA: FBSS is a major source of chronic neuropathic pain and affects up to 40% of patients who undergo lumbosacral spine surgery for back pain. Thus far, few economic analyses have been performed comparing the various treatments for FBSS, with these studies involving small sample sizes. In addition, the nationwide practices in the use of SCS for FBSS are unknown. METHODS: The MarketScan data set was used to analyze patients with FBSS who underwent SCS or spinal reoperation between 2000 and 2009. Propensity score methods were used to match patients who underwent SCS with those who underwent lumbar reoperation to examine health care resource utilization. Postoperative complications were analyzed with multivariate logistic regression. Health care use was analyzed using negative binomial and general linear models. RESULTS: The study cohort included 16,455 patients with FBSS, with 395 undergoing SCS implantation (2.4%). Complication rates at 90 days were significantly lower for SCS than spinal reoperation (P < 0.0001). Also in the matched cohort, hospital stay (P < 0.0001) and associated charges (P = 0.016) were lower for patients with SCS. However outpatient, emergency room, and medication charges were similar between the 2 groups. Overall cost totaling $82,586 at 2 years was slightly higher in the lumbar reoperation group than in the SCS group with total cost of $80,669 (P = 0.88). CONCLUSION: Although previous studies have demonstrated superior efficacy for the treatment of FBSS, SCS remains underused. Despite no significant decreases in overall health care cost with SCS implantation, because it is associated with decreased complications and improved outcomes, this technology warrants closer consideration for the management of chronic pain in patients with FBSS.

Low-grade astrocytomas: the prognostic value of fibrillary, gemistocytic, and protoplasmic tumor histology.

OBJECT: Low-grade astrocytomas are slow-growing, infiltrative gliomas that over time may progress into more malignant tumors. Various factors have been shown to affect the time to progression and overall survival including age, performance status, tumor size, and the extent of resection. However, more recently it has been suggested that histological subtypes (fibrillary, protoplasmic, and gemistocytic) may impact patient outcome. In this study the authors have performed a large comparative population-based analysis to examine the characteristics and survival of patients with the various subtypes of WHO Grade II astrocytomas. METHODS: Patients diagnosed with fibrillary, protoplasmic, and gemistocytic astrocytomas were identified through the Surveillance, Epidemiology, and End Results (SEER) database. The chi-square test and Student t-test were used to evaluate differences in patient and treatment characteristics between astrocytoma subtypes. Kaplan-Meier analysis was used to assess overall survival, and the log-rank test was used to evaluate the differences between survival curves. Univariate and multivariate analyses were also performed to determine the effect of various patient, tumor, and treatment variables on overall survival. RESULTS: A total of 500 cases were included in the analysis, consisting of 326 fibrillary (65.2%), 29 protoplasmic (5.8%), and 145 gemistocytic (29%) variants. Gemistocytic astrocytomas presented at a significantly older age than the fibrillary variant (46.8 vs 37.7 years, p < 0.0001), with protoplasmic and fibrillary subtypes having a similar age. Although protoplasmic and fibrillary variants underwent radiotherapy at similar rates, gemistocytic tumors more frequently received radiotherapy (p = 0.0001). Univariate analysis revealed older age, larger tumor size, and the use of radiotherapy to be poor prognostic factors, with resection being associated with improved survival. The gemistocytic subtype (hazard ratio [HR] 1.62 [95% CI 1.27-2.07], p = 0.0001) also resulted in significantly worse survival than fibrillary tumors. Bivariate analyses demonstrated that older age, the use of radiotherapy, and resection significantly influenced median survival. Tumor subtype also affected median survival; patients who harbored gemistocytic tumors experienced less than half the median survival of fibrillary and protoplasmic tumors (38 vs 82 months, p = 0.0003). Multivariate analysis revealed increasing age (HR 1.05 [95% CI 1.04-1.05], p < 0.0001), larger tumor size (HR 1.02 [95% CI 1.01-1.03], p = 0.0002), and the use of resection (HR 0.70 [95% CI 0.52-0.94], p = 0.018) to be independent predictors of survival. Examination of tumor subtype revealed that the gemistocytic variant (HR 1.30 [95% CI 0.98-1.74], p = 0.074) was associated with worse patient survival than fibrillary tumors, although this only approached significance. The protoplasmic subtype did not affect overall survival (p = 0.33). CONCLUSIONS: Gemistocytic tumor histology was associated with worse survival than fibrillary and protoplasmic astrocytomas. As protoplasmic astrocytomas have a survival similar to fibrillary tumors, there may be limited utility to the identification of this rare variant. However, increased attention should be paid to the presence of gemistocytes in low-grade gliomas as this is associated with shorter time to progression, increased malignant transformation, and reduced overall survival.

Vestibular schwannomas in the modern era: epidemiology, treatment trends, and disparities in management.

OBJECT: There are a variety of treatment options for the management of vestibular schwannomas (VSs), including microsurgical resection, radiotherapy, and observation. Although the choice of treatment is dependent on various patient factors, physician bias has been shown to significantly affect treatment choice for VS. In this study the authors describe the current epidemiology of VS and treatment trends in the US in the modern era. They also illustrate patient and tumor characteristics and elucidate their effect on tumor management. METHODS: Patients diagnosed with VS were identified through the Surveillance, Epidemiology, and End Results database, spanning the years 2004-2009. Age-adjusted incidence rates were calculated and adjusted using the 2000 US standard population. The chi-square and Student t-tests were used to evaluate differences between patient and tumor characteristics. Multivariate logistic regression was performed to determine the effects of various patient and tumor characteristics on the choice of tumor treatment. RESULTS: A total of 6225 patients with VSs treated between 2004 and 2009 were identified. The overall incidence rate was 1.2 per 100,000 population per year. The median age of patients with VS was 55 years, with the majority of patients being Caucasian (83.16%). Of all patients, 3053 (49.04%) received surgery only, with 1466 (23.55%) receiving radiotherapy alone. Both surgery and radiation were only used in 123 patients (1.98%), with 1504 patients not undergoing any treatment (24.16%). Increasing age correlated with decreased use of surgery (OR 0.95, 95% CI 0.95-0.96; p<0.0001), whereas increasing tumor size was associated with the increased use of surgery (OR 1.04, 95% CI 1.04-1.05; p<0.0001). Older age was associated with an increased likelihood of conservative management (OR 1.04, 95% CI 1.04-1.05; p<0.0001). Racial disparities were also seen, with African American patients being significantly less likely to receive surgical treatment compared with Caucasians (OR 0.50, 95% CI 0.35-0.70; p<0.0001), despite having larger tumors at diagnosis. CONCLUSIONS: The incidence of vestibular schwannomas in the US is 1.2 per 100,000 population per year. Although many studies have demonstrated improved outcomes with the use of radiotherapy for small- to medium-sized VSs, surgery is still the most commonly used treatment modality for these tumors. Racial disparities also exist in the treatment of VSs, with African American patients being half as likely to receive surgery and nearly twice as likely to have their VSs managed conservatively despite presenting with larger tumors. Further studies are needed to elucidate the reasons for treatment disparities and investigate the nationwide trend of resection for the treatment of small VSs.

Disparities in the outcomes of lumbar spinal stenosis surgery based on insurance status.

STUDY DESIGN: Retrospective cohort study using Thomson Reuter's MarketScan database. OBJECTIVE: To evaluate the extent to which Medicaid versus commercial insurance status affects outcomes after lumbar stenosis surgery. SUMMARY OF BACKGROUND DATA: The Affordable Care Act aims to expand health insurance and to help narrow existing health care disparities. Medicaid patients have previously been noted to be at an increased risk for impaired access to health care. Conversely, those with commercial insurance may be subject to overtreatment. We examine the surgical treatment of low back pain as an example that has raised significant public health concerns. METHODS: A total of 28,462 patients, ages 18 and older, were identified who had undergone laminectomy or fusion for spinal stenosis between 2000 and 2009. Patients were characterized by baseline demographic information, comorbidity burden, and type of insurance (Medicaid vs. commercial insurance). Multivariate analysis was performed comparing the relative effect of insurance status on reoperation rates, timing and type of reoperations, postoperative complications, and total postoperative health resource use. RESULTS: Medicaid patients had similar reoperation rates to commercially insured patients at 1 year (4.60% vs. 5.42%, P = .38); but had significantly lower reoperation rates at 2 (7.22% vs. 10.30%; adjusted odds ratio [aOR] = 0.661; 95% confidence interval [CI], 0.533-0.820; P = .0002) and more than 2 years (13.92% vs. 16.89%; aOR = 0.722; 95% CI, 0.612-0.851; P <.0001). Medicaid patients were particularly less likely to undergo fusion as a reoperation (aOR = 0.478; 95% CI, 0.377-0.606; P < 0001). Medicaid patients had greater health care resource utilization as measured by hospital days, outpatient services and medications prescribed; however, commercially insured patients had significantly higher overall health utilization costs at 1 and 2 years. CONCLUSION: There are insurance disparities that affect important surgical outcomes after initial surgery for spinal stenosis. Efforts for national health care reform should include explicit efforts to identify such system factors that will reduce current inequities in care. LEVEL OF EVIDENCE: 2.

Racial disparities in outcomes of spinal surgery for lumbar stenosis.

STUDY DESIGN: A retrospective, cross-sectional study. OBJECTIVE: To evaluate racial disparities in outcomes of lumbar stenosis surgery. SUMMARY OF BACKGROUND DATA: Racial inequalities have been described in the outcomes of cardiovascular and orthopedic procedures. There have been minimal investigation of racial disparities in complications and costs of lumbar laminectomies and fusions. METHODS: We analyzed the Medicaid data set of Thomson Reuter's MarketScan database. African-American and non-Hispanic white patients who underwent laminectomy or fusion for lumbar stenosis with at least 2 years postoperative data were included. We examined the effect of race on the rate of reoperations, complications, and the cost associated with surgery. RESULTS: African-American patients in the Medicaid database were at no higher risk for reoperation in the 2 years after an operation for lumbar stenosis than white patients (7.14% vs. 7.89%, P = 0.7895). However, we did find that African-American patients were more likely to experience postoperative complications of any kind, even after adjusting for length of hospital stay, comorbidities, sex, and age (adjusted odds ratio = 1.819, P = 0.0123 for immediate complication; adjusted odds ratio = 1.746, P = 0.0141 for 30-d complication; and adjusted odds ratio = 1.611, P = 0.0410 for 90-d complication). White patients had a significantly shorter length of stay (3 vs. 5 d, P < 0.007) and accrued fewer hospital-related costs ($16,148 vs. $24,267, P < 0.0007). African-American patients, despite having more comorbidities in our sample, were prescribed significantly fewer medications in the 2 years after index procedures (91 vs. 138 prescriptions, P < 0.0007) and had fewer medication costs during the 2 years after surgery ($5297 vs. $8450, P < 0.0007). CONCLUSION: At the national level, there are several racial disparities in the rate of complications, length of stay, and costs after surgery for lumbar spinal stenosis. LEVEL OF EVIDENCE: 3.

Cancer after spinal fusion: the role of bone morphogenetic protein.

BACKGROUND: Bone morphogenetic protein (BMP) is used in tens of thousands of spinal fusions each year. A trial evaluating a high-dose BMP formulation demonstrated that its use may be associated with an increased risk of cancer. OBJECTIVE: To evaluate whether BMP, as commonly used today, is associated with an increased risk of cancer or benign tumors. METHODS: We performed a retrospective study using the Thomson Reuter MarketScan database. We retained all patients who had no previous diagnosis of cancer or benign tumor and had at least 2 years of uninterrupted enrollment in the database before and after their operations. A propensity score--matched cohort was created to ensure greater covariate balance between treatment groups. RESULTS: Within the propensity score--matched cohort (n = 4698), BMP-exposed patients had a nonsignificant increase in the rate of cancer diagnosis (9.37% vs 7.92%; P = .08). After adjustment for covariates, BMP exposure was associated with a 31% increased risk of benign tumor diagnosis (odds ratio, 1.31; 95% confidence interval, 1.02-1.68; P < .05). When the benign tumor diagnoses were stratified by organ type, BMP patients had significantly more diagnoses of benign nervous system tumors (0.81% vs 0.34%; P = .03), and within this group, benign tumors of the spinal meninges were much more common in the BMP-treated group (0.13% vs 0.02%; P = .002). CONCLUSION: The results of this large, independent, propensity-matched study suggest that the use of BMP in lumbar fusions is associated with a significantly higher rate of benign neoplasms but not malignancies.