CCR2 and CCR5 co-inhibition modulates immunosuppressive myeloid milieu in glioma and synergizes with anti-PD-1 therapy.

Immunotherapy has revolutionized the treatment of cancers. Reinvigorating lymphocytes with checkpoint blockade has become a cornerstone of immunotherapy for multiple tumor types, but the treatment of glioblastoma has not yet shown clinical efficacy. A major hurdle to treat GBM with checkpoint blockade is the high degree of myeloid-mediated immunosuppression in brain tumors that limits CD8 T-cell activity. A potential strategy to improve anti-tumor efficacy against glioma is to use myeloid-modulating agents to target immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment. We found that the co-inhibition of the chemokine receptors CCR2 and CCR5 in murine model of glioma improves the survival and synergizes robustly with anti-PD-1 therapy. Moreover, the treatment specifically reduced the infiltration of monocytic-MDSCs (M-MDSCs) into brain tumors and increased lymphocyte abundance and cytokine secretion by tumor-infiltrating CD8 T cells. The depletion of T-cell subsets and myeloid cells abrogated the effects of CCR2 and CCR5 blockade, indicating that while broad depletion of myeloid cells does not improve survival, specific reduction in the infiltration of immunosuppressive myeloid cells, such as M-MDSCs, can boost the anti-tumor immune response of lymphocytes. Our study highlights the potential of CCR2/CCR5 co-inhibition in reducing myeloid-mediated immunosuppression in GBM patients.

Exploring the impact of primary care utilization and health information exchange upon treatment patterns and clinical outcomes of glioblastoma patients.

PURPOSE: There is limited literature describing care coordination for patients with glioblastoma (GBM). We aimed to investigate the impact of primary care and electronic health information exchange (HIE) between neurosurgeons, oncologists, and primary care providers (PCP) on GBM treatment patterns, postoperative outcomes, and survival. METHODS: We identified adult GBM patients undergoing primary resection at our institution (2007-2020). HIE was defined as shared electronic medical information between PCPs, oncologists, and neurosurgeons. Multivariate logistic regression analyses were used to determine the effect of PCPs and HIE upon initiation and completion of adjuvant therapy. Kaplan-Meier and multivariate Cox regression models were used to evaluate overall survival (OS). RESULTS: Among 374 patients (mean age ± SD: 57.7 ± 13.5, 39.0% female), 81.0% had a PCP and 62.4% had electronic HIE. In multivariate analyses, having a PCP was associated with initiation (OR: 7.9, P < 0.001) and completion (OR: 4.4, P < 0.001) of 6 weeks of concomitant chemoradiation, as well as initiation (OR: 4.0, P < 0.001) and completion (OR: 3.0, P = 0.007) of 6 cycles of maintenance temozolomide thereafter. Having a PCP (median OS [95%CI]: 14.6[13.1-16.1] vs. 10.8[8.2-13.3] months, P = 0.005) and HIE (15.40[12.82-17.98] vs. 13.80[12.51-15.09] months, P = 0.029) were associated with improved OS relative to counterparts in Kaplan-Meier analysis and in multivariate Cox regression analysis (hazard ratio [HR] = 0.7, [95% CI] 0.5-1.0, P = 0.048). In multivariate analyses, chemoradiation (HR = 0.34, [95% CI] 0.2-0.7, P = 0.002) and maintenance temozolomide (HR = 0.5, 95%CI 0.3-0.8, P = 0.002) were associated with improved OS relative to counterparts. CONCLUSION: Effective care coordination between neurosurgeons, oncologists, and PCPs may offer a modifiable avenue to improve GBM outcomes.

The Hospital Frailty Risk Score Independently Predicts Postoperative Outcomes in Glioblastoma Patients.

OBJECTIVE: The Hospital Frailty Risk Score (HFRS) is a tool for quantifying patient frailty using International Classification of Diseases, Tenth Revision codes. This study aimed to determine the utility of the HFRS in predicting surgical outcomes after resection of glioblastoma (GBM) and compare its prognostic ability with other validated indices such as American Society of Anesthesiologists score and Charlson Comorbidity Index. METHODS: A retrospective analysis was conducted using a GBM patient database (2017-2019) at a single institution. HFRS was calculated using International Classification of Diseases, Tenth Revision codes. Bivariate logistic regression was used to model prognostic ability of each frailty index, and model discrimination was assessed using area under the receiver operating characteristic curve. Multivariate linear and logistic regression models were used to assess for significant associations between HFRS and continuous and binary postoperative outcomes, respectively. RESULTS: The study included 263 patients with GBM. The HFRS had a significantly greater area under the receiver operating characteristic curve compared with American Society of Anesthesiologists score (P = 0.016) and Charlson Comorbidity Index (P = 0.037) for predicting 30-day readmission. On multivariate analysis, the HFRS was significantly and independently associated with hospital length of stay (P = 0.0038), nonroutine discharge (P = 0.018), and 30-day readmission (P = 0.0051). CONCLUSIONS: The HFRS has utility in predicting postoperative outcomes for patients with GBM and more effectively predicts 30-day readmission than other frailty indices. The HFRS may be used as a tool for optimizing clinical decision making to reduce adverse postoperative outcomes in patients with GBM.

GPR68-ATF4 signaling is a novel prosurvival pathway in glioblastoma activated by acidic extracellular microenvironment.

BACKGROUND: Glioblastoma multiforme (GBM) stands as a formidable challenge in oncology because of its aggressive nature and severely limited treatment options. Despite decades of research, the survival rates for GBM remain effectively stagnant. A defining hallmark of GBM is a highly acidic tumor microenvironment, which is thought to activate pro-tumorigenic pathways. This acidification is the result of altered tumor metabolism favoring aerobic glycolysis, a phenomenon known as the Warburg effect. Low extracellular pH confers radioresistant tumors to glial cells. Notably GPR68, an acid sensing GPCR, is upregulated in radioresistant GBM. Usage of Lorazepam, which has off target agonism of GPR68, is linked to worse clinical outcomes for a variety of cancers. However, the role of tumor microenvironment acidification in GPR68 activation has not been assessed in cancer. Here we interrogate the role of GPR68 specifically in GBM cells using a novel highly specific small molecule inhibitor of GPR68 named Ogremorphin (OGM) to induce the iron mediated cell death pathway: ferroptosis. METHOD: OGM was identified in a non-biased zebrafish embryonic development screen and validated with Morpholino and CRISPR based approaches. Next, A GPI-anchored pH reporter, pHluorin2, was stably expressed in U87 glioblastoma cells to probe extracellular acidification. Cell survival assays, via nuclei counting and cell titer glo, were used to demonstrate sensitivity to GPR68 inhibition in twelve immortalized and PDX GBM lines. To determine GPR68 inhibition's mechanism of cell death we use DAVID pathway analysis of RNAseq. Our major indication, ferroptosis, was then confirmed by western blotting and qRT-PCR of reporter genes including TFRC. This finding was further validated by transmission electron microscopy and liperfluo staining to assess lipid peroxidation. Lastly, we use siRNA and CRISPRi to demonstrate the critical role of ATF4 suppression via GPR68 for GBM survival. RESULTS: We used a pHLourin2 probe to demonstrate how glioblastoma cells acidify their microenvironment to activate the commonly over expressed acid sensing GPCR, GPR68. Using our small molecule inhibitor OGM and genetic means, we show that blocking GPR68 signaling results in robust cell death in all thirteen glioblastoma cell lines tested, irrespective of genetic and phenotypic heterogeneity, or resistance to the mainstay GBM chemotherapeutic temozolomide. We use U87 and U138 glioblastoma cell lines to show how selective induction of ferroptosis occurs in an ATF4-dependent manner. Importantly, OGM was not-acutely toxic to zebrafish and its inhibitory effects were found to spare non-malignant neural cells. CONCLUSION: These results indicate GPR68 emerges as a critical sensor for an autocrine pro-tumorigenic signaling cascade triggered by extracellular acidification in glioblastoma cells. In this context, GPR68 suppresses ATF4, inhibition of GPR68 increases expression of ATF4 which leads to ferroptotic cell death. These findings provide a promising therapeutic approach to selectively induce ferroptosis in glioblastoma cells while sparing healthy neural tissue.

Soluble PD-L1 reprograms blood monocytes to prevent cerebral edema and facilitate recovery after ischemic stroke.

Acute cerebral ischemia triggers a profound inflammatory response. While macrophages polarized to an M2-like phenotype clear debris and facilitate tissue repair, aberrant or prolonged macrophage activation is counterproductive to recovery. The inhibitory immune checkpoint Programmed Cell Death Protein 1 (PD-1) is upregulated on macrophage precursors (monocytes) in the blood after acute cerebrovascular injury. To investigate the therapeutic potential of PD-1 activation, we immunophenotyped circulating monocytes from patients and found that PD-1 expression was upregulated in the acute period after stroke. Murine studies using a temporary middle cerebral artery (MCA) occlusion (MCAO) model showed that intraperitoneal administration of soluble Programmed Death Ligand-1 (sPD-L1) significantly decreased brain edema and improved overall survival. Mice receiving sPD-L1 also had higher performance scores short-term, and more closely resembled sham animals on assessments of long-term functional recovery. These clinical and radiographic benefits were abrogated in global and myeloid-specific PD-1 knockout animals, confirming PD-1+ monocytes as the therapeutic target of sPD-L1. Single-cell RNA sequencing revealed that treatment skewed monocyte maturation to a non-classical Ly6Clo, CD43hi, PD-L1+ phenotype. These data support peripheral activation of PD-1 on inflammatory monocytes as a therapeutic strategy to treat neuroinflammation after acute ischemic stroke.

Management and Molecular Characterization of Intraventricular Glioblastoma: A Single-Institution Case Series.

While the central nervous system (CNS) tumor classification has increasingly incorporated molecular parameters, there is a paucity of literature reporting molecular alterations found in intraventricular glioblastoma (IVGBM), which are rare. We present a case series of nine IVGBMs, including molecular alterations found in standardized next-generation sequencing (NGS). We queried the clinical charts, operative notes, pathology reports, and radiographic images of nine patients with histologically confirmed IVGBM treated at our institution (1995-2021). Routine NGS was performed on resected tumor tissue of two patients. In this retrospective case series of nine patients (22% female, median (range) age: 64.3 (36-85) years), the most common tumor locations were the atrium of the right lateral ventricle (33%) and the septum pellucidum (33%). Five patients had preoperative hydrocephalus, which was managed with intraoperative external ventricular drains in three patients and ventriculoperitoneal shunts in one patient. Hydrocephalus was managed with subtotal resection of a fourth ventricular IVGBM in one patient. The most common surgical approach was transcortical intraventricular (56%). Gross total resection was achieved in two patients, subtotal resection was achieved in six patients, and one patient received a biopsy only. Immunohistochemistry for IDH1 R132H mutant protein was performed in four cases and was negative in all four. Genetic alterations common in glioblastoma, IDH-wildtype, were seen in two cases with available NGS data, including EGFR gene amplification, TERT promoter mutation, PTEN mutation, trisomy of chromosome 7, and monosomy of chromosome 10. Following surgical resection, four patients received adjuvant chemoradiation. Median survival among our cohort was 4.7 months (IQR: 0.9-5.8 months). Management of IVGBM is particularly challenging due to their anatomical location, presentation with obstructive hydrocephalus, and fast growth, necessitating prompt intervention. Additional studies are needed to better understand the genetic landscape of IVGBM compared to parenchymal glioblastoma and may further elucidate the unique pathophysiology of these rare tumors.

An asynchronous web-based intervention for neurosurgery residents to improve education on cost-effective care.

OBJECTIVE: To gauge resident knowledge in the socioeconomic aspects of neurosurgery and assess the efficacy of an asynchronous, longitudinal, web-based, socioeconomics educational program tailored for neurosurgery residents. METHODS: Trainees completed a 20-question pre- and post-intervention knowledge examination including four educational categories: billing/coding, procedure-specific concepts, material costs, and operating room protocols. Structured data from 12 index cranial neurosurgical operations were organized into 5 online, case-based modules sent to residents within a single training program via weekly e-mail. Content from each educational category was integrated into the weekly modules for resident review. RESULTS: Twenty-seven neurosurgical residents completed the survey. Overall, there was no statistically significant difference between pre- vs post-intervention resident knowledge of billing/coding (79.2 % vs 88.2 %, p = 0.33), procedure-specific concepts (34.3 % vs 39.2 %, p = 0.11), material costs (31.7 % vs 21.6 %, p = 0.75), or operating room protocols (51.7 % vs 35.3 %, p = 0.61). However, respondents' accuracy increased significantly by 40.8 % on questions containing content presented more than 3 times during the 5-week study period, compared to an increased accuracy of only 2.2 % on questions containing content presented less often during the same time period (p = 0.05). CONCLUSIONS: Baseline resident knowledge in socioeconomic aspects of neurosurgery is relatively lacking outside of billing/coding. Our socioeconomic educational intervention demonstrates some promise in improving socioeconomic knowledge among neurosurgery trainees, particularly when content is presented frequently. This decentralized, web-based approach to resident education may serve as a future model for self-driven learning initiatives among neurosurgical residents with minimal disruption to existing workflows.

The mFI-5 and Postoperative Outcomes in Brain Tumor Patients: A Bayesian Approach to Quantifying Uncertainty.

OBJECTIVE: To the best of our knowledge, prior research has not investigated the uncertainty in the relationship between patient frailty and postoperative outcomes after brain tumor surgery. The present study used Bayesian methods to quantify the statistical uncertainty between the 5-factor modified frailty index (mFI-5) and postoperative outcomes for patients undergoing brain tumor resection. METHODS: The present study used retrospective data collected from patients undergoing brain tumor resection during a 2-year period (2017-2019). Posterior probability distributions were used to estimate the means of model parameters that are most likely given the priors and the data. Additionally, 95% credible intervals (CrIs) were constructed for each parameter estimate. RESULTS: Our patient cohort included 2519 patients with a mean age of 55.27 years. Our multivariate analysis demonstrated that each 1-point increase in the mFI-5 score was associated with an 18.76% (95% CrI, 14.35%-23.36%) increase in hospital length of stay and a 9.37% (CrI, 6.82%-12.07%) increase in hospital charges. We also noted an association between an increasing mFI-5 score and greater odds of a postoperative complication (odds ratio [OR], 1.58; CrI, 1.34-1.87) and a nonroutine discharge (OR, 1.54; CrI, 1.34-1.80). However, no meaningful statistical association was found between the mFI-5 score and 90-day hospital readmission (OR, 1.16; CrI, 0.98-1.36) or between the mFI-5 score and 90-day mortality (OR, 1.12; CrI, 0.83-1.50). CONCLUSIONS: Although mFI-5 scores might be able to effectively predict short-term outcomes such as length of stay, our results demonstrate no meaningful association between mFI-5 scores and 90-day readmission or 90-day mortality. Our study highlights the need for rigorously quantifying statistical uncertainty to safely risk-stratify neurosurgical patients.

Establishing proof of concept for sonolucent cranioplasty and point of care ultrasound imaging after posterior fossa decompression for Chiari malformation.

BACKGROUND: Evaluation after posterior fossa decompression for Chiari malformation can require repeated imaging, particularly with persistent symptoms. Typically, CT or MRI is used. However, CT carries radiation risk and MRI is costly. Ultrasound is an inexpensive, radiation-free, point-of-care modality that has, thus far, been limited by intact skull and traditional cranioplasty materials. Ultrasound also allows for imaging in different head positions and body postures, which may lend insight into cause for persistent symptoms despite adequate decompression on traditional neutral static CT or MRI. We evaluate safety and feasibility of ultrasound as a post-operative imaging modality in patients reconstructed with sonolucent cranioplasty during posterior fossa decompression for Chiari malformation. METHODS: Outcomes were analyzed for 26 consecutive patients treated with a Chiari-specific sonolucent cranioplasty. This included infection, need for revision, CSF leak, and pseudomeningocele. Ultrasound was performed point-of-care in the outpatient clinic by the neurosurgery team to assess feasibility. RESULTS: In eight months mean follow up, there were no surgical site infections or revisions with this novel sonolucent cranioplasty. Posterior fossa anatomy was discernable via transcutaneous ultrasound obtained point-of-care in the clinic setting at follow up visits. CONCLUSION: We demonstrate proof of concept for ultrasound as a post-operative imaging modality after posterior fossa decompression for Chiari malformation. With further investigation, ultrasound may prove to serve as an alternative to CT and MRI in this patient population, or as an adjunct to provide positional and dynamic information. Use of sonolucent cranioplasty is safe. This technique deserves further study.

Deoxyhypusine hydroxylase: A novel therapeutic target differentially expressed in short-term vs long-term survivors of glioblastoma.

Glioblastoma (GB) is the most aggressive neoplasm of the brain. Poor prognosis is mainly attributed to tumor heterogeneity, invasiveness and drug resistance. Only a small fraction of GB patients survives longer than 24 months from the time of diagnosis (ie, long-term survivors [LTS]). In our study, we aimed to identify molecular markers associated with favorable GB prognosis as a basis to develop therapeutic applications to improve patients' outcome. We have recently assembled a proteogenomic dataset of 87 GB clinical samples of varying survival rates. Following RNA-seq and mass spectrometry (MS)-based proteomics analysis, we identified several differentially expressed genes and proteins, including some known cancer-related pathways and some less established that showed higher expression in short-term (<6 months) survivors (STS) compared to LTS. One such target found was deoxyhypusine hydroxylase (DOHH), which is known to be involved in the biosynthesis of hypusine, an unusual amino acid essential for the function of the eukaryotic translation initiation factor 5A (eIF5A), which promotes tumor growth. We consequently validated DOHH overexpression in STS samples by quantitative polymerase chain reaction (qPCR) and immunohistochemistry. We further showed robust inhibition of proliferation, migration and invasion of GB cells following silencing of DOHH with short hairpin RNA (shRNA) or inhibition of its activity with small molecules, ciclopirox and deferiprone. Moreover, DOHH silencing led to significant inhibition of tumor progression and prolonged survival in GB mouse models. Searching for a potential mechanism by which DOHH promotes tumor aggressiveness, we found that it supports the transition of GB cells to a more invasive phenotype via epithelial-mesenchymal transition (EMT)-related pathways.

Self-assembling paclitaxel-mediated stimulation of tumor-associated macrophages for postoperative treatment of glioblastoma.

The unique cancer-associated immunosuppression in brain, combined with a paucity of infiltrating T cells, contributes to the low response rate and poor treatment outcomes of T cell-based immunotherapy for patients diagnosed with glioblastoma multiforme (GBM). Here, we report on a self-assembling paclitaxel (PTX) filament (PF) hydrogel that stimulates macrophage-mediated immune response for local treatment of recurrent glioblastoma. Our results suggest that aqueous PF solutions containing aCD47 can be directly deposited into the tumor resection cavity, enabling seamless hydrogel filling of the cavity and long-term release of both therapeutics. The PTX PFs elicit an immune-stimulating tumor microenvironment (TME) and thus sensitizes tumor to the aCD47-mediated blockade of the antiphagocytic "don't eat me" signal, which subsequently promotes tumor cell phagocytosis by macrophages and also triggers an antitumor T cell response. As adjuvant therapy after surgery, this aCD47/PF supramolecular hydrogel effectively suppresses primary brain tumor recurrence and prolongs overall survivals with minimal off-target side effects.

First Experience With Postoperative Transcranial Ultrasound Through Sonolucent Burr Hole Covers in Adult Hydrocephalus Patients.

BACKGROUND: Managing patients with hydrocephalus and cerebrospinal fluid (CSF) disorders requires repeated head imaging. In adults, it is typically computed tomography (CT) or less commonly magnetic resonance imaging (MRI). However, CT poses cumulative radiation risks and MRI is costly. Ultrasound is a radiation-free, relatively inexpensive, and optionally point-of-care alternative, but is prohibited by very limited windows through an intact skull. OBJECTIVE: To describe our initial experience with transcutaneous transcranial ultrasound through sonolucent burr hole covers in postoperative hydrocephalus and CSF disorder patients. METHODS: Using cohort study design, infection and revision rates were compared between patients who underwent sonolucent burr hole cover placement during new ventriculoperitoneal shunt placement and endoscopic third ventriculostomy over the 1-year study time period and controls from the period 1 year before. Postoperatively, trans-burr hole ultrasound was performed in the clinic, at bedside inpatient, and in the radiology suite to assess ventricular anatomy. RESULTS: Thirty-seven patients with sonolucent burr hole cover were compared with 57 historical control patients. There was no statistically significant difference in infection rates between the sonolucent burr hole cover group (1/37, 2.7%) and the control group (0/57, P = .394). Revision rates were 13.5% vs 15.8% (P = 1.000), but no revisions were related to the burr hole or cranial hardware. CONCLUSION: Trans-burr hole ultrasound is feasible for gross evaluation of ventricular caliber postoperatively in patients with sonolucent burr hole covers. There was no increase in infection rate or revision rate. This imaging technique may serve as an alternative to CT and MRI in the management of select patients with hydrocephalus and CSF disorders.

Predictors of surgical site infection in glioblastoma patients undergoing craniotomy for tumor resection.

OBJECTIVE: Surgical site infections (SSIs) burden patients and healthcare systems, often requiring additional intervention. The objective of this study was to identify the relationship between preoperative predictors inclusive of scalp incision type and postoperative SSI following glioblastoma resection. METHODS: The authors retrospectively reviewed cases of glioblastoma resection performed at their institution from December 2006 to December 2019 and noted preoperative demographic and clinical presentations, excluding patients missing these data. Preoperative nutritional indices were available for a subset of cases. Scalp incisions were categorized as linear/curvilinear, reverse question mark, trapdoor, or frontotemporal. Patients were dichotomized by SSI incidence. Multivariable logistic regression was used to determine predictors of SSI. RESULTS: A total of 911 cases of glioblastoma resection were identified, 30 (3.3%) of which demonstrated postoperative SSI. There were no significant differences in preoperative malnutrition or number of surgeries between SSI and non-SSI cases. The SSI cases had a significantly lower preoperative Karnofsky Performance Status (KPS) than the non-SSI cases (63.0 vs 75.1, p < 0.0001), were more likely to have prior radiation history (43.3% vs 26.4%, p = 0.042), and were more likely to have received steroids both preoperatively and postoperatively (83.3% vs 54.5%, p = 0.002). Linear/curvilinear incisions were more common in non-SSI than in SSI cases (56.9% vs 30.0%, p = 0.004). Trapdoor scalp incisions were more frequent in SSI than non-SSI cases (43.3% vs 24.2%, p = 0.012). On multivariable analysis, a lower preoperative KPS (OR 1.04, 95% CI 1.02-1.06), a trapdoor scalp incision (OR 3.34, 95% CI 1.37-8.49), and combined preoperative and postoperative steroid administration (OR 3.52, 95% CI 1.41-10.7) were independently associated with an elevated risk of postoperative SSI. CONCLUSIONS: The study findings indicated that SSI risk following craniotomy for glioblastoma resection may be elevated in patients with a low preoperative KPS, a trapdoor scalp incision during surgery, and steroid treatment both preoperatively and postoperatively. These data may help guide future operative decision-making for these patients.

Patient Safety Indicator 04 Does Not Consistently Identify Failure to Rescue in the Neurosurgical Population.

BACKGROUND: Improving neurosurgical quality metrics necessitates the analysis of patient safety indicator (PSI) 04, a measure of failure to rescue (FTR). OBJECTIVE: To demonstrate that PSI 04 is not an appropriate measure for capturing FTR within neurosurgery. METHODS: We conducted a single-center retrospective cohort study. Patients from January 1, 2017 to June 1, 2021, who sustained a PSI 04-attributed complication (pneumonia, deep vein thrombosis/pulmonary embolism, sepsis, shock/cardiac arrest, or gastrointestinal hemorrhage/acute ulcer), underwent a neurosurgical procedure, had inpatient mortality, and were identified using patient safety indicator 04 (PSI 04) tracking algorithm. The primary outcome was whether the attributed PSI 04 designation was the primary driver of mortality. RESULTS: We identified 67 patients who met the PSI 04 criteria (median age, 61 years; female sex, 43.4%). Nearly 20% of patients met the PSI complication criteria before admission. Patients who underwent emergent bedside procedures were more likely to present with a poor Glasgow Coma Scale ( P = .016), more likely to be intubated before admission ( P = .016), and less likely to have mortality due to a PSI 04-related complication ( P = .002). PSI 04-related complications were identified as the cause of death in only 43.2% of cases. Procedures occurring in the interventional radiology suite (odds ratio, 23.2; 95% CI, 3.5-229.3; P = .003) or the operating room (odds ratio, 6.2; 95% CI, 1.25-39.5; P = .03) were more likely to have mortality because of a PSI 04-related complication compared with bedside procedures. CONCLUSION: In total, 65.7% of patients were inappropriately flagged as meeting PSI 04 criteria. PSI 04 currently identifies patients with complications unrelated to operating room procedures. Improvement in patient safety within neurosurgery necessitates the development of a subspecialty specific measure to capture FTR.

Recruitment of women in neurosurgery: a 7-year quantitative analysis.

OBJECTIVE: The authors aimed to characterize which US medical schools have the most female neurosurgery residents and to identify potential associations between medical school characteristics and successful recruitment of women pursuing a neurosurgery career. METHODS: The authors evaluated a total of 1572 residents in US neurosurgery programs accredited by the Accreditation Council for Graduate Medical Education as of February 2021, representing match cohorts from 2014 to 2020. The authors extracted US medical school characteristics and ranked schools based on the percentages of women graduates entering neurosurgery. They additionally studied yearly trends of the percentage of women constituting incoming neurosurgery resident cohorts as well as associations between female recruitment percentage and medical school characteristics using univariable and stepwise multivariable linear regression (including significant univariable factors). RESULTS: The cohort consisted of 1255 male and 317 (20%) female residents. Yearly trends indicated a significant drop in incoming female residents in 2016, followed by significant increases in 2017 and 2019. On multivariable analysis, the following factors were associated with a higher average percentage of female graduates entering neurosurgery: total affiliated neurosurgery clinical faculty (ß = 0.006, 95% CI 0.001-0.011, p = 0.01), allopathic versus osteopathic schools (ß = 0.231, 95% CI 0.053-0.409, p = 0.01), and top 10 U.S. News & World Report ranking (ß = 0.380, 95% CI 0.129-0.589, p < 0.01). When the number of female clinical faculty was added to the model, the variable was not statistically significant. Multivariable bibliometric analyses indicated a higher mean preresidency H-index for men, with an even greater gender difference identified in the 2021 H-index. CONCLUSIONS: This study characterizes which medical schools are most successful at recruiting female students who constituted the total neurosurgery resident workforce of the 2020-2021 academic year. The overall number of clinical neurosurgery faculty rather than faculty gender was independently associated with female recruitment. Gender differences in research productivity persisted with control for confounders and increased between preresidency and 2021 time points. Such understanding of factors that influence the recruitment of women can help improve female representation in neurosurgery residency training moving forward.

Automatic detection of foreign body objects in neurosurgery using a deep learning approach on intraoperative ultrasound images: From animal models to first in-human testing.

Objects accidentally left behind in the brain following neurosurgical procedures may lead to life-threatening health complications and invasive reoperation. One of the most commonly retained surgical items is the cotton ball, which absorbs blood to clear the surgeon's field of view yet in the process becomes visually indistinguishable from the brain parenchyma. However, using ultrasound imaging, the different acoustic properties of cotton and brain tissue result in two discernible materials. In this study, we created a fully automated foreign body object tracking algorithm that integrates into the clinical workflow to detect and localize retained cotton balls in the brain. This deep learning algorithm uses a custom convolutional neural network and achieves 99% accuracy, sensitivity, and specificity, and surpasses other comparable algorithms. Furthermore, the trained algorithm was implemented into web and smartphone applications with the ability to detect one cotton ball in an uploaded ultrasound image in under half of a second. This study also highlights the first use of a foreign body object detection algorithm using real in-human datasets, showing its ability to prevent accidental foreign body retention in a translational setting.

MCP-1/CCR2 axis inhibition sensitizes the brain microenvironment against melanoma brain metastasis progression.

Development of resistance to chemo- and immunotherapies often occurs following treatment of melanoma brain metastasis (MBM). The brain microenvironment (BME), particularly astrocytes, cooperate toward MBM progression by upregulating secreted factors, among which we found that monocyte chemoattractant protein-1 (MCP-1) and its receptors, CCR2 and CCR4, were overexpressed in MBM compared with primary lesions. Among other sources of MCP-1 in the brain, we show that melanoma cells altered astrocyte secretome and evoked MCP-1 expression and secretion, which in turn induced CCR2 expression in melanoma cells, enhancing in vitro tumorigenic properties, such as proliferation, migration, and invasion of melanoma cells. In vivo pharmacological blockade of MCP-1 or molecular knockout of CCR2/CCR4 increased the infiltration of cytotoxic CD8+ T cells and attenuated the immunosuppressive phenotype of the BME as shown by decreased infiltration of Tregs and tumor-associated macrophages/microglia in several models of intracranially injected MBM. These in vivo strategies led to decreased MBM outgrowth and prolonged the overall survival of the mice. Our findings highlight the therapeutic potential of inhibiting interactions between BME and melanoma cells for the treatment of this disease.

Predictors and Impact of Postoperative 30-Day Readmission in Glioblastoma.

BACKGROUND: Postoperative 30-day readmissions have been shown to negatively affect survival and other important outcomes in patients with glioblastoma (GBM). OBJECTIVE: To further investigate patient readmission risk factors of primary and recurrent patients with GBM. METHODS: The authors retrospectively reviewed records of 418 adult patients undergoing 575 craniotomies for histologically confirmed GBM at an academic medical center. Patient demographics, comorbidities, and clinical characteristics were collected and compared by patient readmission status using chi-square and Mann-Whitney U testing. Multivariable logistic regression was performed to identify risk factors that predicted 30-day readmissions. RESULTS: The cohort included 69 (12%) 30-day readmissions after 575 operations. Readmitted patients experienced significantly lower median overall survival (11.3 vs 16.4 months, P = .014), had a lower mean Karnofsky Performance Scale score (66.9 vs 74.2, P = .005), and had a longer initial length of stay (6.1 vs 5.3 days, P = .007) relative to their nonreadmitted counterparts. Readmitted patients experienced more postoperative deep vein thromboses or pulmonary embolisms (12% vs 4%, P = .006), new motor deficits (29% vs 14%, P = .002), and nonhome discharges (39% vs 22%, P = .005) relative to their nonreadmitted counterparts. Multivariable analysis demonstrated increased odds of 30-day readmission with each 10-point decrease in Karnofsky Performance Scale score (odds ratio [OR] 1.32, P = .002), each single-point increase in 5-factor modified frailty index (OR 1.51, P = .016), and initial presentation with cognitive deficits (OR 2.11, P = .013). CONCLUSION: Preoperatively available clinical characteristics strongly predicted 30-day readmissions in patients undergoing surgery for GBM. Opportunities may exist to optimize preoperative and postoperative management of at-risk patients with GBM, with downstream improvements in clinical outcomes.

Reexamining the Role of Postoperative ICU Admission for Patients Undergoing Elective Craniotomy: A Systematic Review.

OBJECTIVES: The standard-of-care for postoperative care following elective craniotomy has historically been ICU admission. However, recent literature interrogating complications and interventions during this postoperative ICU stay suggests that all patients may not require this level of care. Thus, hospitals began implementing non-ICU postoperative care pathways for elective craniotomy. This systematic review aims to summarize and evaluate the existing literature regarding outcomes and costs for patients receiving non-ICU care after elective craniotomy. DATA SOURCES: A systematic review of the PubMed database was performed following PRISMA guidelines from database inception to August 2021. STUDY SELECTION: Included studies were published in peer-reviewed journals, in English, and described outcomes for patients undergoing elective craniotomies without postoperative ICU care. DATA EXTRACTION: Data regarding study design, patient characteristics, and postoperative care pathways were extracted independently by two authors. Quality and risk of bias were evaluated using the Oxford Centre for Evidence-Based Medicine Levels of Evidence tool and Risk Of Bias In Non-Randomized Studies-of Interventions tool, respectively. DATA SYNTHESIS: In total, 1,131 unique articles were identified through the database search, with 27 meeting inclusion criteria. Included articles were published from 2001 to 2021 and included non-ICU inpatient care and same-day discharge pathways. Overall, the studies demonstrated that postoperative non-ICU care for elective craniotomies led to length of stay reduction ranging from 6 hours to 4 days and notable cost reductions. Across 13 studies, 53 of the 2,469 patients (2.1%) intended for postoperative management in a non-ICU setting required subsequent care escalation. CONCLUSIONS: Overall, these studies suggest that non-ICU care pathways for appropriately selected postcraniotomy patients may represent a meaningful opportunity to improve care value. However, included studies varied greatly in patient selection, postoperative care protocol, and outcomes reporting. Standardization and multi-institutional collaboration are needed to draw definitive conclusions regarding non-ICU postoperative care for elective craniotomy.

Impact of virtual vs. in-person interviews among neurosurgery residency applicants.

BACKGROUND: The interview is considered a key factor in selecting residents in various medical and surgical specialties. However, the reliability of the interview process in selecting neurosurgery training program applicants remains largely under-investigated. OBJECTIVE: To investigate the reliability of the interview process for neurosurgery residency applicants and to evaluate the impact of virtual interviews on this process. METHODS: We analyzed the records of neurosurgery residency applicant interviews at our institution between 2016 and 2021. An average of 20 neurosurgery faculty members (clinical and research) interviewed each applicant and graded them 1 (best) to 4 (worst). Intraclass correlation coefficient (ICC) and Levene's test were used to assess the inter-rater and intra-rater reliability, respectively. RESULTS: 214 neurosurgery residency applicants were interviewed at a single institution between 2016 and 2021. The mean applicant rating each year ranged from 1.77 to 1.92. Inter-rater agreement was relatively poor in each year, (ICC < 0.5, P < 0.05). Among 60% of the raters, variability of scores significantly changed from year to year, (p < 0.05). When comparing the scores submitted during the virtual interview process (2021) with the scores submitted in the previous years (2016-2020), 2 interviewers (10%) had less variability using the virtual process. CONCLUSION: Our analysis found that the current interview process for neurosurgery residency applicants' selection suffers from poor inter- and intra-rater reliability. Virtual interviews may be part of a cost-effective strategy to improve the reliability of the interview process. Further validation is needed, as well as identification of novel strategies to maximize the reliability of the selection process.