Learning Curves during Implementation of Robotic Stereotactic Surgery.

INTRODUCTION: Adoption of robotic techniques is increasing for neurosurgical applications. Common cranial applications include stereoelectroencephalography (sEEG) and deep brain stimulation (DBS). For surgeons to implement robotic techniques in these procedures, realistic learning curves must be anticipated for surgeons to overcome the challenges of integrating new techniques into surgical workflow. One such way of quantifying learning curves in surgery is cumulative sum (CUSUM) analysis. METHODS: Here, the authors present retrospective review of stereotactic cases to perform a CUSUM analysis of operative time for robotic cases at a single institution performed by 2 surgeons. The authors demonstrate learning phase durations of 20 and 16 cases in DBS and sEEG, respectively. RESULTS: After plateauing of operative time, mastery phases started at cases 132 and 72 in DBS and sEEG. A total of 273 cases (188 DBS and 85 sEEG) were included in the study. The authors observed a learning plateau concordant with change of location of surgery after exiting the learning phase. CONCLUSION: This study demonstrates the learning curve of 2 stereotactic workflows when integrating robotics as well as being the first study to examine the robotic learning curve in DBS via CUSUM analysis. This work provides data on what surgeons may expect when integrating this technology into their practice for cranial applications.

Comparison of the transarterial, transvenous, and superior ophthalmic vein approaches in the treatment of indirect carotid-cavernous fistulas.

OBJECTIVE: Indirect carotid-cavernous fistulas (CCFs) are abnormal arteriovenous shunting lesions with a highly variable clinical presentation that depends on the drainage pattern. Based on venous drainage, treatment can be either transarterial (TA) or transvenous (TV). The aim of this study was to compare the outcomes of indirect CCF embolization via the TA, TV, and direct superior ophthalmic vein (SOV) approaches. METHODS: The authors conducted a retrospective analysis of 74 patients admitted to their institution from 2010 to 2023 with the diagnosis of 77 indirect CCFs as confirmed on digital subtraction angiography. RESULTS: A total of 74 patients with 77 indirect CCFs were included in this study. Embolization was performed via the TA approach in 4 cases, the TV approach in 50 cases, and the SOV in 23 cases. At the end of the procedure, complete occlusion was achieved in 76 (98.7%) cases. The rate of complete occlusion at the end of the procedure and at last radiological follow-up was significantly higher in the SOV and TV cohorts than in the TA cohort. The rate of recurrence was highest in the TA cohort (25% for TA vs 5.3% for TV vs 0% for SOV, p = 0.68). CONCLUSIONS: The rate of immediate complete occlusion was higher in the TV and SOV cohorts than in the TA cohort while the rate of complete occlusion at final follow-up was highest in the SOV cohort. The SOV approach was significantly associated with higher rates of postoperative complications. Indirect CCFs require careful examination of the fistulous point and the venous drainage to provide the most effective patient-tailored approach.

Causes and Predictors of 30-Day Readmission in Patients With Stroke Undergoing Mechanical Thrombectomy: A Large Single-Center Experience.

BACKGROUND AND OBJECTIVES: The 30-day readmission rate has emerged as a metric of quality care and is associated with increased health care expenditure. We aim to identify the rate and causes of 30-day readmission after mechanical thrombectomy and provide the risk factors of readmission to highlight high-risk patients who may require closer care. METHODS: This is a retrospective study from a prospectively maintained database of 703 patients presenting for mechanical thrombectomy between 2017 and 2023. All patients who presented with a stroke and underwent a mechanical thrombectomy were included in this study. Patients who were deceased on discharge were excluded from this study. RESULTS: Our study comprised 703 patients, mostly female (n = 402, 57.2%) with a mean age of 70.2 years ±15.4. The most common causes of readmission were cerebrovascular events (stroke [n = 21, 36.2%], intracranial hemorrhage [n = 9, 15.5%], and transient ischemic attack [n = 1, 1.7%]).Other causes of readmission included cardiovascular events (cardiac arrest [n = 4, 6.9%] and bradycardia [n = 1, 1.7%]), infection (wound infection postcraniectomy [n = 3, 5.2%], and pneumonia [n = 1, 1.7%]). On multivariate analysis, independent predictors of 30-day readmission were history of smoking (odds ratio [OR]: 2.2, 95% CI: 1.1-4.2) P = .01), distal embolization (OR: 3.2, 95% CI: 1.1-8.7, P = .03), decompressive hemicraniectomy (OR: 9.3, 95% CI: 3.2-27.6, P < .01), and intracranial stent placement (OR: 4.6, 95% CI: 2.4-8.7) P < .01). CONCLUSION: In our study, the rate of 30-day readmission was 8.3%, and the most common cause of readmission was recurrent strokes. We identified a history of smoking, distal embolization, decompressive hemicraniectomy, and intracranial stenting as independent predictors of 30-day readmission in patients with stroke undergoing mechanical thrombectomy.

Transradial versus transfemoral access routes for diagnostic cerebral angiography: a large single-center comparative cost-analysis study.

OBJECTIVE: Recently, the transradial (TR) approach has become a common alternative because of its safety profile and increased patient satisfaction compared with the transfemoral (TF) route. Both routes are associated with their respective associated costs, and differences typically emerge on the basis of patient anatomy, operator expertise, and occurrence of complications. The authors' objective was to compare the overall costs of diagnostic cerebral angiography via both routes and to shed light on the individual equipment costs of each route. METHODS: This retrospective single-center study of 926 elective diagnostic angiograms was performed between December 2019 and March 2022. RESULTS: The study comprised of 314 and 612 angiograms performed through the TF and TR routes, respectively. A significantly greater proportion of female patients were included in the TF cohort (79.3% vs 67.8%, p < 0.001), and most other demographic characteristics and baseline modified Rankin Scale scores were comparable between cohorts. The overall cost of patients utilizing the TR route was comparable to that of the TF route (mean ± SD $12,591.80 ± $19,128.00 vs $12,789.50 ± 18,424.00, p = 0.88). However, the median cost of catheters was significantly higher in TR group ($55.20 vs $12.40, p = 0.03), while the median costs of closure devices ($87.00 vs $20.20 p < 0.001) and sheaths ($44.60 ± 11.3 vs $41.10 ± 3.10, p < 0.001) were significantly higher in the TF group. CONCLUSIONS: Overall, the authors' study showed that the TR approach can be a less expensive option for patients undergoing diagnostic cerebral angiography, especially if complications occur. Future studies may corroborate these findings and potentially lead to the adoption of TR as a low-cost, efficient, gold-standard technique for cerebral angiography.

Predictors of recurrence after surgical resection of parafalcine and parasagittal meningiomas.

PURPOSE: Owing to their vicinity near the superior sagittal sinus, parasagittal and parafalcine meningiomas are challenging tumors to surgically resect. In this study, we investigate key factors that portend increased risk of recurrence after surgery. METHODS: This is a retrospective study of patients who underwent resection of parasagittal and parafalcine meningiomas at our institution between 2012 and 2018. Relevant clinical, radiographic, and histopathological variables were selected for analysis as predictors of tumor recurrence. RESULTS: A total of 110 consecutive subjects (mean age: 59.4 ± 15.2 years, 67.3% female) with 74 parasagittal and 36 parafalcine meningiomas (92 WHO grade 1, 18 WHO grade 2/3), are included in the study. A total of 37 patients (33.6%) exhibited recurrence with median follow-up of 42 months (IQR: 10-71). In the overall cohort, parasagittal meningiomas exhibited shorter progression-free survival compared to parafalcine meningiomas (Kaplan-Meier log-rank p = 0.045). On univariate analysis, predictors of recurrence include WHO grade 2/3 vs. grade 1 tumors (p < 0.001), higher Ki-67 indices (p < 0.001), partial (p = 0.04) or complete sinus invasion (p < 0.001), and subtotal resection (p < 0.001). Multivariable Cox regression analysis revealed high-grade meningiomas (HR: 3.62, 95% CI: 1.60-8.22; p = 0.002), complete sinus invasion (HR: 3.00, 95% CI: 1.16-7.79; p = 0.024), and subtotal resection (HR: 3.10, 95% CI: 1.38-6.96; p = 0.006) as independent factors that portend shorter time to recurrence. CONCLUSION: This study identifies several pertinent factors that confer increased risk of recurrence after resection of parasagittal and parafalcine meningiomas, which can be used to devise appropriate surgical strategy to achieve improved patient outcomes.

The Rate and Predictors of 30-Day Readmission in Patients Treated for Unruptured Cerebral Aneurysms: A Large Single-Center Study.

BACKGROUND AND OBJECTIVES: Numerous studies of various populations and diseases have shown that unplanned 30-day readmission rates are positively correlated with increased morbidity and all-cause mortality. In this study, we aim to provide the rate and predictors of 30-day readmission in patients undergoing treatment for unruptured intracranial aneurysms. METHODS: This is a retrospective study of 525 patients presenting for aneurysm treatment between 2017 and 2022. All patients who were admitted and underwent a successful treatment of their unruptured intracerebral aneurysms were included in the study. The primary outcome was the rate and predictors of 30-day readmission. RESULTS: The rate of 30-day readmission was 6.3%, and the mean duration to readmission was 7.8 days ± 6.9. On univariate analysis, factors associated with 30-day readmission were antiplatelet use on admission (odds ratio [OR]: 0.4, P = .009), peri-procedural rupture (OR: 15.8, P = .007), surgical treatment of aneurysms (OR: 2.2, P = .035), disposition to rehabilitation (OR: 9.5, P < .001), and increasing length of stay (OR: 1.1, P = .0008). On multivariate analysis, antiplatelet use on admission was inversely correlated with readmission (OR: 0.4, P = .045), whereas peri-procedural rupture (OR: 9.5, P = .04) and discharge to rehabilitation (OR: 4.5, P = .029) were independent predictors of 30-day readmission. CONCLUSION: In our study, risk factors for 30-day readmission were aneurysm rupture during the hospital stay and disposition to rehabilitation, whereas the use of antiplatelet on admission was inversely correlated with 30-day readmission. Although aneurysm rupture is a nonmodifiable risk factor, more studies are encouraged to focus on the correlation of antiplatelet use and rehabilitation disposition with 30-day readmission rates.

Predictors of Transfemoral Access Site Complications in Neuroendovascular Procedures: A large Single-Center Cohort Study.

OBJECTIVE: The transfemoral (TF) route has historically been the preferred access site for endovascular procedures. However, despite its widespread use, TF procedures may confer morbidity as a result of access site complications. The aim of this study is to provide the rate and predictors of TF access site complications for neuroendovascular procedures. METHODS: This is a single center retrospective study of TF neuroendovascular procedures performed between 2017 and 2022. The incidence of complications and associated risk factors were analyzed across a large cohort of patients. RESULTS: The study comprised of 2043 patients undergoing transfemoral neuroendovascular procedures. The composite rate of access site complications was 8.6 % (n = 176). These complications were divided into groin hematoma formation (n = 118, 5.78 %), retroperitoneal hematoma (n = 14, 0.69 %), pseudoaneurysm formation (n = 40, 1.96 %), and femoral artery occlusion (n = 4, 0.19 %). The cross-over to trans radial access rate was 1.1 % (n = 22). On univariate analysis, increasing age (OR=1.0, p = 0.06) coronary artery disease (OR=1.7, p = 0.05) peripheral vascular disease (OR=1.9, p = 0.07), emergent mechanical thrombectomy procedures (OR=2.1, p < 0.001) and increasing sheath size (OR=1.3, p < 0.001) were associated with higher TF access site complications. On multivariate analysis, larger sheath size was an independent risk factor for TF access site complications (OR=1.8, p = 0.02). CONCLUSION: Several pertinent factors contribute towards the incidence of TF access site complications. Factors associated with TF access site complications include patient demographics (older age) and clinical risk factors (vascular disease), as well as periprocedural factors (sheath size).

Radiomic signatures of meningiomas using the Ki-67 proliferation index as a prognostic marker of clinical outcomes.

OBJECTIVE: The clinical behavior of meningiomas is not entirely captured by its designated WHO grade, therefore other factors must be elucidated that portend increased tumor aggressiveness and associated risk of recurrence. In this study, the authors identify multiparametric MRI radiomic signatures of meningiomas using Ki-67 as a prognostic marker of clinical outcomes independent of WHO grade. METHODS: A retrospective analysis was conducted of all resected meningiomas between 2012 and 2018. Preoperative MR images were used for high-throughput radiomic feature extraction and subsequently used to develop a machine learning algorithm to stratify meningiomas based on Ki-67 indices < 5% and ≥ 5%, independent of WHO grade. Progression-free survival (PFS) was assessed based on machine learning prediction of Ki-67 strata and compared with outcomes based on histopathological Ki-67. RESULTS: Three hundred forty-three meningiomas were included: 291 with WHO grade I, 43 with grade II, and 9 with grade III. The overall rate of recurrence was 19.8% (15.1% in grade I, 44.2% in grade II, and 77.8% in grade III) over a median follow-up of 28.5 months. Grade II and III tumors had higher Ki-67 indices than grade I tumors, albeit tumor and peritumoral edema volumes had considerable variation independent of meningioma WHO grade. Forty-six high-performing radiomic features (1 morphological, 7 intensity-based, and 38 textural) were identified and used to build a support vector machine model to stratify tumors based on a Ki-67 cutoff of 5%, with resultant areas under the curve of 0.83 (95% CI 0.78-0.89) and 0.84 (95% CI 0.75-0.94) achieved for the discovery (n = 257) and validation (n = 86) data sets, respectively. Comparison of histopathological Ki-67 versus machine learning-predicted Ki-67 showed excellent performance (overall accuracy > 80%), with classification of grade I meningiomas exhibiting the greatest accuracy. Prediction of Ki-67 by machine learning classifier revealed shorter PFS for meningiomas with Ki-67 indices ≥ 5% compared with tumors with Ki-67 < 5% (p < 0.0001, log-rank test), which corroborates divergent patient outcomes observed using histopathological Ki-67. CONCLUSIONS: The Ki-67 proliferation index may serve as a surrogate marker of increased meningioma aggressiveness independent of WHO grade. Machine learning using radiomic feature analysis may be used for the preoperative prediction of meningioma Ki-67, which provides enhanced analytical insights to help improve diagnostic classification and guide patient-specific treatment strategies.

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.

A Comparison of Outcomes Between Transfemoral Versus Transradial Access for Carotid Stenting.

BACKGROUND: The transradial (TR) approach has emerged as an alternative to the transfemoral (TF) approach in carotid artery stenting (CAS) because of its perceived benefits in access site complications and overall patient experience. OBJECTIVE: To assess outcomes of TF vs TR approach for CAS. METHODS: This is a retrospective single-center review of patients receiving CAS through the TR or TF route between 2017 and 2022. All patients with symptomatic and asymptomatic carotid disease who underwent attempted CAS were included in our study. RESULTS: A total of 342 patients were included in this study: 232 underwent CAS through TF approach vs 110 through the TR route. On univariate analysis, the rate of overall complications was more than double for the TF vs TR cohort; however, this did not achieve statistical significance (6.5% vs 2.7%, odds ratio [OR] = 0.59 P = .36). The rate of cross-over from TR to TF was significantly higher on univariate analysis (14.6 % vs 2.6%, OR = 4.77, P = .005) and on inverse probability treatment weighting analysis (OR = 6.11, P < .001). The rate of in-stent stenosis (TR: 3.6% vs TF: 2.2%, OR = 1.71, P = .43) and strokes at follow-up (TF: 2.2% vs TR: 1.8%, OR = 0.84, P = .84) was not significantly different. Finally, median length of stay was comparable between both cohorts. CONCLUSION: The TR approach is safe, feasible, and provides similar rates of complications and high rates of successful stent deployment compared with the TF route. Neurointerventionalists adopting the radial first approach should carefully assess the preprocedural computed tomography angiography to identify patients amenable to TR approach for carotid stenting.

Triphasic response after endoscopic craniopharyngioma resection and its dependency on infundibular preservation or sacrifice.

OBJECTIVE: Surgery is the primary treatment for craniopharyngioma with the preservation of hypothalamic function of paramount importance. Infundibular preservation is debated, as maximal resection decreases recurrence rates but causes hypopituitarism. A triphasic response of diabetes insipidus (DI), syndrome of inappropriate antidiuretic hormone secretion (SIADH), and recurrent DI has been described after pituitary surgery, but the impact of infundibular preservation on the triphasic response following craniopharyngioma resection has not been well established. The authors' objective was to assess postoperative fluid and sodium balance and differences in ADH imbalance management following endonasal craniopharyngioma resection based on infundibular transection status. METHODS: This is a retrospective cohort study of 19 patients with craniopharyngioma treated with endoscopic endonasal resection between 2014 and 2021. Resection was dichotomized into infundibular transection or preservation. Postoperative triphasic response, time to DI, and time to ADH replacement were compared using Fisher's exact test and Kaplan-Meier analysis. RESULTS: Based on surgeon impression, 10 patients had infundibular transection and 9 had infundibular preservation. Overall, 16 patients experienced DI, 12 experienced persistent DI, and 6 experienced SIADH. A postoperative triphasic response occurred in 40% (n = 4) of transection patients without preoperative DI and 11% (n = 1) of preservation patients without preoperative DI. The median time to postoperative DI (0.5 vs 18.0 hours, p = 0.022) and median time to ADH replacement therapy (4.5 vs 24 hours, p = 0.0004) were significantly shorter in the transection group than in the preservation group. CONCLUSIONS: Following endonasal craniopharyngioma resection, the triphasic response occurs in nearly half of infundibular transection cases. DI begins earlier with infundibular transection. On the basis of the study findings in which no patients met the criteria for SIADH or were endocrinologically unstable after postoperative day 6, it is reasonable to suggest that otherwise stable patients can be discharged at or before postoperative day 6 when ADH fluctuations have normalized and endocrinopathy is appropriately managed with oral desmopressin. Infundibular transection status may impact postoperative hormonal replacement strategies, but additional studies should evaluate their efficacies.

Radiographic Differentiation of Secretory Meningiomas and WHO Grade 2 Meningiomas: When Atypical Features Are Not Always Predictive of Atypical Tumors.

OBJECTIVE: Secretory meningioma (SM) is a rare subtype of World Health Organization (WHO) grade 1 meningioma, associated with significant peritumoral brain edema (PTBE). Because of this, SM may be mistaken preoperatively to be a WHO grade 2 meningioma (G2M). In this study, we identified radiographic features to differentiate these 2 tumor types preoperatively to help inform surgical decision-making. METHODS: We performed a retrospective review of all patients with histologically confirmed intracranial SM and G2M at a single institution from 2000 to 2019. Relevant clinic, demographic and radiographic data were collected. We performed a stepwise multivariable logistic regression to identify independent predictors of SM. RESULTS: A total of 43 SM and 140 G2M patients were included in this study. In multivariable analysis, severe PTBE, meaning edema size greater than tumor size (odds ratio [OR] 4.44, P = 0.01), tumor hyperintensity on fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging sequences (OR 7.80, P = 0.002), and higher normalized apparent diffusion coefficient (nADC) values (OR 1.54, P < 0.001) were strong predictors of SM. Conversely, larger tumor volume (OR 1.79 per 10 mL volume increase, P < 0.001) and cystic component (OR 12.50, P = 0.007) correlated with G2M. CONCLUSIONS: In this study, we found that preoperative FLAIR hyperintensity, severe PTBE, and higher nADC values correlated with SM pathology, and larger size and cystic component were associated with G2M. Accurate identification of SM on preoperative imaging may provide surgeons useful information in decision-making.

Epidemiology of primary malignant non-osseous spinal tumors in the United States.

BACKGROUND CONTEXT: Primary malignant non-osseous spinal tumors are relatively rare and this has led to a paucity of studies specifically examining the epidemiology of malignant spinal tumors. PURPOSE: To provide an updated and more comprehensive study examining the epidemiology and relative survival of these rare tumors. STUDY DESIGN/SETTING: Data was retrospectively acquired from the Central Brain Tumor Registry of the United States (CBTRUS). PATIENT SAMPLE: Primary malignant non-osseous spinal tumor cases diagnosed between 2000 and 2017 in the United States. OUTCOME MEASURES: Incidence rates (IRs), relative survival rates, and hazard ratios (HR) were measured. METHODS: IRs were calculated only for histologically-confirmed cases between 2000 and 2017. Relative survival estimates were calculated from survival information on malignant spinal tumors between 2001 and 2016 for death from any cause. Multivariable Cox proportional hazards regression models were constructed to control for age, sex, race, and ethnicity. RESULTS: From 2000 to 2017, approximately 587 new cases of malignant non-osseous spinal tumors were diagnosed every year in the United States. The overall IR was 0.178 per 100,000 persons. Ependymomas were the most commonly diagnosed tumor in all age groups. The 10-year relative survival rates were 94.1%, 62.1%, 62.0%, and 13.3% for ependymomas, lymphomas, diffuse astrocytomas, and high-grade astrocytomas, respectively. Females have a significantly lower risk of death as compared with males for ependymomas (HR: 0.74, p<.001) and diffuse astrocytomas (HR: 0.70, p=.005). African-Americans have a significantly higher risk of death compared with Caucasians when diagnosed with ependymomas (HR: 1.52, p=.009) or lymphomas (HR: 1.55, p=.009). CONCLUSION: Primary malignant non-osseous spinal tumors are primarily diagnosed in adulthood or late adulthood. Ependymal tumors are the most commonly diagnosed primary malignant non-osseous spinal tumors and have the highest 10-year relative survival rates. High-grade astrocytomas are rare and portend the worst prognosis.

Adjuvant radiation versus observation with salvage radiation after gross-total resection of WHO grade II meningiomas: a propensity score-adjusted analysis.

OBJECTIVE: After gross-total resection (GTR) of a newly diagnosed WHO grade II meningioma, the decision to treat with radiation upfront or at initial recurrence remains controversial. A comparison of progression-free survival (PFS) between observation and adjuvant radiation fails to account for the potential success of salvage radiation, and a direct comparison of PFS between adjuvant and salvage radiation is hampered by strong selection bias against salvage radiation cohorts in which only more aggressive, recurrent tumors are included. To account for the limitations of traditional PFS measures, the authors evaluated radiation failure-free survival (RFFS) between two treatment strategies after GTR: adjuvant radiation versus observation with salvage radiation, if necessary. METHODS: The authors performed a retrospective review of patients who underwent GTR of newly diagnosed WHO grade II meningiomas at their institution between 1996 and 2019. They assessed traditional PFS in patients who underwent adjuvant radiation, postoperative observation, and salvage radiation. For RFFS, treatment failure was defined as time from initial surgery to failure of first radiation. To assess the association between treatment strategy and RFFS while accounting for potential confounders, a multivariable Cox regression analysis adjusted for the propensity score (PS) and inverse probability of treatment weighted (IPTW) Cox regression analysis were performed. RESULTS: A total of 160 patients underwent GTR and were included in this study. Of the 121 patients who underwent observation, 32 (26.4%) developed recurrence and required salvage radiation. PFS at 3, 5, and 10 years after observation was 75.1%, 65.6%, and 45.5%, respectively. PFS at 3 and 5 years after salvage radiation was 81.7% and 61.3%, respectively. Of 160 patients, 39 received adjuvant radiation, and 3- and 5-year PFS/RFFS rates were 86.1% and 59.2%, respectively. In patients who underwent observation with salvage radiation, if necessary, the 3-, 5-, and 10-year RFFS rates were 97.7%, 90.3%, and 87.9%, respectively. Both PS and IPTW Cox regression models demonstrated that patients who underwent observation with salvage radiation treatment, if necessary, had significantly longer RFFS (PS model: hazard ratio [HR] 0.21, p < 0.01; IPTW model: HR 0.21, p < 0.01). CONCLUSIONS: In this retrospective, nonrandomized study, adjuvant radiation after GTR of a WHO II meningioma did not add significant benefit over a strategy of observation and salvage radiation at initial recurrence, if necessary, but results must be considered in the context of the limitations of the study design.

Surgical Site Infection Prophylaxis and Wound Management in Spine Surgery.

Surgical site infection (SSI) is a potentially devastating complication of spinal surgery that increases patient morbidity and healthcare costs. SSIs have complex and multifactorial etiologies; therefore, there are numerous opportunities for prevention and risk mitigation. The aim of this narrative review was to describe the incidence, risk factors, and outcomes of SSIs in spine surgery with an emphasis on postoperative wound care. We list and describe the preoperative, intraoperative, and postoperative evidence-based interventions that can be applied to potentially prevent SSI after spinal surgery.

Outcomes of salvage radiation for recurrent world health organization grade II meningiomas: a retrospective cohort study.

PURPOSE: The optimal modality of radiation-intensity-modulated radiation therapy (IMRT) or stereotactic radiosurgery (SRS)-in patients with recurrent WHO grade II meningiomas is not well-established. The purpose of this study was to compare progression-free survival (PFS) in patients undergoing salvage IMRT vs SRS. We compared PFS in those with and without history of prior radiation. METHODS: Forty-two patients with 71 tumor recurrences treated with IMRT or SRS were retrospectively reviewed. Thirty-two salvage treatments were performed on recurrent tumors never treated with prior radiation ('radiation-naïve' cohort), whereas 39 salvage treatments were performed on recurrent tumors previously treated with radiation ('re-treatment cohort'). RESULTS: In the 'radiation-naïve' cohort, 3-year PFS for IMRT and SRS was 68.8% and 60.7%, respectively (p = 0.61). The median tumor volume for patients treated with IMRT was significantly larger than for patients treated with SRS (5.7 vs 2.2 cm3; p = 0.04). The 3-year PFS for salvage IMRT or SRS in the 're-treatment' cohort was 45.4% vs 65.8% in the 'radiation-naïve' cohort (p = 0.008). When analyzing the outcome of multiple re-treatments, median PFS was 47 months for 1st or 2nd salvage radiation (IMRT or SRS) compared to 16 months for the 3rd or greater salvage radiation treatment (p = 0.003). CONCLUSION: For salvage radiation of recurrent grade II tumors that are 'radiation-naïve', comparable 3-year PFS rates were found between IMRT and SRS, despite the IMRT group having significantly larger tumors. Salvage radiation overall was less successful in the 're-treatment' cohort compared with the 'radiation-naïve' cohort. Additionally, the effectiveness of radiation significantly declines with successive salvage radiation treatments.

Descriptive epidemiology of craniopharyngiomas in the United States.

PURPOSE: Craniopharyngiomas are rare benign brain tumors originating from errors in differentiation during embryogenesis. Given current interest in treatments that target genetic and molecular signatures of specific craniopharyngioma subtypes, updated and comprehensive epidemiologic data of these subtypes are necessary to inform and direct resources. METHODS: We utilized data from the Central Brain Tumor Registry of the United States (CBTRUS), which represents 100% of the US population. Incidence by demographics was calculated only for histologically-confirmed cases. Age-adjusted annual incidence was calculated and is reported per 100,000 persons. Annual percent change (APC) in incidence rates from 2004 to 2016 was calculated to assess trends. RESULTS: From 2004 to 2016, 7441 craniopharyngiomas were diagnosed in the United States, representing approximately 620 new cases each year. The incidence for histologically-confirmed cases was 0.16 per 100,000 persons. The age distribution was bimodal, with one peak in 5- to 9-year-olds and another in 55- to 69-year-olds. Compared with adamantinomatous tumors, papillary craniopharyngiomas only represented 5.5% of the histologically diagnosed craniopharyngiomas in 0- to 29-year-olds, 30.6% in 30- to 59-year-olds, and 30.4% in 60 + year-olds. Incidence was highest amongst Blacks (0.22), followed by Whites (0.15), Asians or Pacific Islanders (0.14), and American Indians/Alaska Natives (0.10). No significant difference was discovered in incidence rates between males and females or Hispanic and non-Hispanic ethnicities. CONCLUSIONS: Craniopharyngiomas are rare tumors with a bimodal age distribution and an equal male-to-female incidence. Black patients had the highest incidence, and adamantinomatous craniopharyngiomas were significantly more common than papillary tumors in adolescent, adult, and elderly populations.

Glioblastoma Myeloid-Derived Suppressor Cell Subsets Express Differential Macrophage Migration Inhibitory Factor Receptor Profiles That Can Be Targeted to Reduce Immune Suppression.

The application of tumor immunotherapy to glioblastoma (GBM) is limited by an unprecedented degree of immune suppression due to factors that include high numbers of immune suppressive myeloid cells, the blood brain barrier, and T cell sequestration to the bone marrow. We previously identified an increase in immune suppressive myeloid-derived suppressor cells (MDSCs) in GBM patients, which correlated with poor prognosis and was dependent on macrophage migration inhibitory factor (MIF). Here we examine the MIF signaling axis in detail in murine MDSC models, GBM-educated MDSCs and human GBM. We found that the monocytic subset of MDSCs (M-MDSCs) expressed high levels of the MIF cognate receptor CD74 and was localized in the tumor microenvironment. In contrast, granulocytic MDSCs (G-MDSCs) expressed high levels of the MIF non-cognate receptor CXCR2 and showed minimal accumulation in the tumor microenvironment. Furthermore, targeting M-MDSCs with Ibudilast, a brain penetrant MIF-CD74 interaction inhibitor, reduced MDSC function and enhanced CD8 T cell activity in the tumor microenvironment. These findings demonstrate the MDSC subsets differentially express MIF receptors and may be leveraged for specific MDSC targeting.

Evolution of Minimally Invasive Lumbar Spine Surgery.

Spine surgery has evolved over centuries from first being practiced with Hippocratic boards and ladders to now being able to treat spinal pathologies with minimal tissue invasion. With the advent of new imaging and surgical technologies, spine surgeries can now be performed minimally invasively with smaller incisions, less blood loss, quicker return to daily activities, and increased visualization. Modern minimally invasive procedures include percutaneous pedicle screw fixation techniques and minimally invasive lateral approach for lumbar interbody fusion (i.e., minimally invasive transforaminal lumbar interbody fusion, extreme lateral interbody fusion, oblique lateral interbody fusion) and midline lumbar fusion with cortical bone trajectory screws. Just as evolutions in surgical techniques have helped revolutionize the field of spine surgery, imaging technologies have also contributed significantly. The advent of computer image guidance has allowed spine surgeons to advance their ability to refine surgical techniques, increase the accuracy of spinal hardware placement, and reduce radiation exposure to the operating room staff. As the field of spine surgery looks to the future, many novel technologies are on the horizon, including robotic spine surgery, artificial intelligence, and machine learning to help improve preoperative planning, improve surgical execution, and optimize patient selection to ensure improved postoperative outcomes and patient satisfaction. As more spine surgeons begin incorporating these novel minimally invasive techniques into practice, the field of minimally invasive spine surgery will continue to innovate and evolve over the coming years.

Exploring ventricular dysfunction and poor venous drainage during robotic mitral valve surgery.

BACKGROUND: del Nido (DN) cardioplegia is commonly used during robotic mitral valve surgery. Poor venous drainage during surgery may result in venous backpressure and washout of this one-shot cardioplegia, limiting its cardioprotective effects. METHODS: One hundred eighty-seven patients undergoing isolated robotic mitral valve surgery, from January 2015 to July 2017, were retrospectively reviewed. Intraoperative central venous pressure (CVP) tracings were reviewed and venous drainage was categorized as good or poor and the relationship of the quality of venous drainage to postoperative ventricular dysfunction (operationalized as the need for inotropic support during and after weaning from cardiopulmonary bypass [CPB]) was assessed. RESULTS: Drainage was judged to be good in 107 patients and poor in 79 patients. On univariate analysis, 23 patients (41%) with good drainage required inotropic support whereas 33 patients (59%) with poor drainage required inotropic support (P = .0025). On multivariable analysis, poor venous drainage remained significantly associated with inotropic use even after adjusting for cross-clamp and CPB time. Inotrope use was associated with significantly longer intensive care unit length of stay (P = .027). CONCLUSION: Maintenance of excellent venous drainage, as assessed by CVP monitoring, should be a high priority in isolated robotic mitral valve surgery undertaken with DN cardioplegia.